Month: October 2026

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Fujifilm NP-W235 Runtime Guide for X-T5, X-H2 and GFX

Short answer: the NP-W235 is the main battery for Fujifilm’s fourth-generation X series and the GFX line, rated 7.2V and about 2200mAh — roughly 70% more capacity than the previous NP-W126S. The X-T5, X-H2, X-H2S, X-S20, X-T4, GFX100S, GFX50S II and GFX100 II all use it and are directly interchangeable. Against Fujifilm’s CIPA figures, a single pack is rated for roughly 450 to 750 shots depending on whether the body has stabilization, its screen spec and its processor load. Real shooting usually comes in below that; plan on about 70%.

This guide gives runtime references by body, then covers the key points on capacity, charging and buying.

1. Runtime reference by body

The table puts CIPA figures alongside the range most users see in practice, to help size your spare count. The real-world range assumes room temperature, limited playback and no wireless.

Body CIPA reference Common real range Suggested spares
X-S20 About 750 shots About 500-650 shots 2
X-H2 About 680 shots About 450-600 shots 2-3
X-T5 About 580 shots About 400-520 shots 2-3
X-H2S About 580 shots About 380-500 shots 3
X-T4 About 500 shots About 350-450 shots 3
GFX100S About 460 shots About 300-420 shots 3
GFX100 II About 540 shots About 350-450 shots 3

One counter-intuitive point in that ordering: the X-S20 outlasts the higher-positioned X-H2, because its screen and viewfinder specs are more conservative and its processor load lower. The X-H2S, meanwhile, has a stacked sensor and high-speed bursts, so it processes far more data per second and runs noticeably shorter than the X-H2.

The GFX ordering deserves attention too. GFX bodies are larger with better heat dissipation, but the medium-format sensor’s readout draw, the bigger viewfinder and the heavier per-frame processing cancel that advantage out. On top of that, GFX users often shoot electronic-shutter bursts and write high-resolution files, which keeps both card and processor under sustained load.

So “a bigger body must be more efficient” is not a rule. Medium format is better planned as one pack per half day, especially for landscape work that involves long periods of live view while waiting — standby draw adds up.

2. Capacity, size and the compatibility boundary

The NP-W235 and NP-W126S are both 7.2V, but their size, compartment structure and contact positions are entirely different, so neither fits the other’s body. This is where upgrades trip people up: moving from an X-T3 to an X-T5 makes every old pack useless, while moving from an X-T4 to an X-T5 keeps them all. For the differences between the two generations, see the notes on the NP-W126S category page.

Within a generation there are details too. Some third-party chargers claim NP-W235 support but have loose slot tolerances, and repeated insertion wears the battery contacts. When buying, favour chargers that state compatibility with the first-party charger.

3. First-party or compatible packs

  1. Use first-party in the primary slot. For long recordings, commercial delivery or cold-weather work, a first-party pack holds a flatter voltage curve and warns earlier, which makes swapping ahead of time easier.
  2. Compatible packs are fine as spares. The second and third packs play a backup role, so a reputable brand with a clear protection-circuit description and stated capacity and batch is enough.
  3. Do not mix batches for long recordings. Differences in internal resistance make one pack sag first, and an interrupted take costs far more than the price gap between packs.
  4. Read the protection spec, not just the capacity. Overcharge, over-discharge, over-temperature and short-circuit protection all being present matters more than an extra 100mAh on the label.

YO’s NP-W235 compatible pack is positioned for spare duty, well suited as a second or third pack; where continuity really matters, the primary slot should still hold a first-party battery. More product details for this model are on the NP-W235 category page.

4. Charging, grips and travel

The X-T5, X-H2 and X-H2S all support USB-C in-body charging; the X-T4’s USB-C port is mainly for data and charging is still dock-based. Carrying a PD charger of 30W or more lets you add meaningful charge over lunch, though charging while shooting generates extra heat.

The X-T4’s VG-XT4 vertical grip holds two more NP-W235 packs, giving a three-battery system that suits events and weddings where you cannot stop to swap. The X-T5 does not support a grip, so that endurance has to come from carrying more packs.

On flights, lithium batteries must stay in the cabin and cannot be checked. For capacity and declaration rules, see the rules for flying with lithium batteries; enforcement is broadly consistent across brands. Pack spares in insulated pouches so the terminals cannot touch metal objects.

FAQ

Can the NP-W235 be used in an X-T3?

No. The X-T3 uses the NP-W126S, and the two differ in compartment dimensions and contact positions, so it will not physically fit.

Are the X-T4 and X-T5 batteries fully interchangeable?

Yes. Both bodies use the NP-W235, so packs swap directly and chargers can be shared.

Is one W235 enough for a wedding?

Usually not. Weddings involve long hours, heavy bursts and frequent playback, so plan on three packs and rotate at roughly one per half day.

Does a compatible battery void the camera warranty?

In most cases no, but if a battery fault damages the body, service may assess causation. Keeping your receipt and choosing a product with a documented protection circuit reduces the risk.

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Five Common DR-FZ100 Mistakes: Mixed Packs, Overnight, Heat

Short answer: the five easiest ways to misuse a DR-FZ100 are — charging new and old packs of different capacity in the same round; leaving it plugged in all night after the lights go green; burying it at the bottom of a camera bag or stacking gear on top; charging in a car or in direct sun; and leaving an empty slot exposed and powered for long periods. None of these is dangerous on its own, but all of them accelerate wear or add risk, and all are cheap to change.

The DR-FZ100 is a dual-slot charging case, not a battery. It charges two NP-FZ100-class packs at once and stores them when closed. Because it is a box, plenty of people treat it as just another accessory to shove in a bag, forgetting that charging actually has temperature and current requirements.

Mistake one: charging two packs in different states

Putting a brand-new TNP-FZ100 alongside an OEM pack that is two years old and down to eighty percent looks harmless, but the two cells accept charge quite differently. The smaller-capacity pack reaches its 4.2V cutoff first; if the circuit shares a single constant-current path, the pack that filled first then sits under a continuous trickle at high voltage.

The subtler problem is consistency: after a few months of mixed charging, the gap in real capacity between the two widens, and it becomes obvious on the day you need one pack to last two hours. Number your packs and pair packs of the same capacity, age and workload as fixed partners.

What to do instead

  • Pair by capacity and purchase date, and keep each pair in the same slot cycle.
  • When the difference between old and new is obvious, do not put them through the same round.
  • With third-party packs from different brands, watch the gap in finishing time; if it is large, charge them separately.

Mistake two: all-night charging

A lithium pack ages markedly faster sitting at 4.2V than at a middle state of charge. The DR-FZ100 normally drops to a trickle or stops output once full, but the pack still sits at full voltage for hours, and the case has little internal volume to dissipate heat. Across a whole night that is not kind to cycle life.

What to do instead

  • Start charging before bed and unplug in the morning, or use a timer socket to cut power after three or four hours.
  • If you do not need a full pack immediately, take it off at eighty or ninety percent rather than chasing the last bar.
  • Before long storage, leave packs at forty to sixty percent — self-discharge and aging are both slowest there.

Mistake three: stacking and crushing

The usual camera-bag scene: the case pushed to the bottom, with a body, lenses and a gimbal on top. The lid takes continuous load, the packs are pressed down, and the contacts carry lateral force. Nothing shows at first, but over time the contacts wear, the shell distorts slightly and the lid closes loosely.

What to do instead

  • Keep the case in the top layer or a side pocket, not underneath everything.
  • Seat packs properly when loading and unloading rather than forcing them.

Mistake four: charging in high heat

Leaving the case charging in a car in summer is the highest-risk habit of the five. A car in sun runs far hotter inside than outside, and charging a lithium pack at that temperature sharply raises the rate of side reactions and visibly accelerates capacity loss; in extreme cases it can trigger thermal runaway.

Another hot scenario that gets missed is charging straight after a shoot. After continuous recording the pack itself is above forty degrees, and plugging it in immediately means adding heat on top of heat. The suitable charging window is usually 10–30°C; outside it, both efficiency and safety margin fall away.

What to do instead

  • Do not charge in the car, in direct sun or next to a radiator.
  • Let a pack that has just come out of the camera cool for twenty minutes first.
  • Do not wrap the case in clothing or a bag while charging; keep it ventilated.
  • In cold conditions, let packs come back to room temperature before charging — the cold-weather notes cover the details.

Mistake five: powered empty slots left open

When only one pack is charging, the other slot is empty, and many people simply leave the case plugged in. That is not dangerous in itself, but it has two practical consequences: an open slot collects dust and metal debris in the contact area, which in quantity causes poor contact; and on some cases the empty slot stays in a detection standby state, drawing repeated tiny currents to no purpose and adding a heat source.

What to do instead

  • Unplug and close the lid when the case is not in use.
  • Check inside the empty slot now and then, and clear dust with a dry soft cloth or an air blower — never scrape the contacts with metal.
  • If you habitually charge only one pack, put the second in as well to cut the time the slot stays exposed.
Mistake Main effect Typical symptom How hard to fix
Mixed pack states Capacity consistency degrades Runtime gap between the two widens Easy, just pair them
Left plugged in overnight Faster capacity loss Noticeably quicker drain after six months Easy, add a timer socket
Stacked and crushed Contact wear, shell distortion Lid feels loose, occasional poor contact Easy, move where it lives
Charging in heat Accelerated aging, safety risk Case feels hot while charging Moderate, change location
Exposed empty slot Dust on contacts, false status Light on but no charge Easy, just close the lid

Not one item in that table costs money. The value of a charging case is that it centralises charging — but if the way you use it is careless, centralising simply magnifies the error, because one mistake affects two packs at once.

If you own packs with a built-in USB-C port such as the TNP-FZ100, there is a more flexible option: travel with a single cable and charge from a power bank, leaving the case at home for storage. The trade-offs between the two routes are in the direct-charge battery category; the case’s own procedures and indicator meanings are in the other articles in the DR-FZ100 category.

FAQ

Can the DR-FZ100 charge OEM and third-party packs at the same time?

Usually yes — the slots are managed independently and mixing does not directly damage anything. But packs with very different capacity and condition will finish far apart, and over time that hurts pairing consistency. Keep similar packs in the same slot rather than placing them at random.

Is it normal for the case to get warm?

Mild warmth is normal; charging involves losses. If it feels properly hot, or one side is much hotter than the other, that usually points to high internal resistance in that pack or a hot charging environment. Test by moving the case and by swapping the pack separately; if it is still hot, stop using it.

Can the case stay plugged in as a permanent dock?

Short term yes, long term no. Constant power keeps the pack at full voltage for hours and adds risk when nobody is watching. Charging to full, then cutting power and closing the lid, is the safer habit.

Does an empty slot slow the other one down?

On most products the slots work independently, so an empty slot does not affect the other’s speed. A few designs share total output, in which case charging both is slower per slot. The output specification in your documentation is the authority.

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Can You Fly With TNP-FZ100 Batteries? Carry-On Rules

Short answer: yes. The TNP-FZ100’s rated energy is about 16.4Wh, far below the 100Wh cabin threshold, so it can travel with you on both domestic and international flights without airline approval. One hard rule still applies: spare lithium batteries go in carry-on only, never in checked baggage. The contacts also need protection against short circuits, and the quantity has to stay within what is reasonable for personal use. Below we separate the arithmetic, the energy bands and the practical security routine so you can tick them off before you leave.

Where 16.4Wh comes from

Aviation rules work in rated energy, in watt-hours, not in milliamp-hours. The formula is capacity times voltage divided by a thousand: 2280mAh × 7.2V ÷ 1000 ≈ 16.4Wh. That is the original NP-FZ100 rating, and the TNP-FZ100 is built to the same specification, so it lands in the same bracket.

The point is worth stressing because people often compare a 20,000mAh power bank with a 2,280mAh camera battery and conclude that the camera battery is “tiny, so obviously fine”. The conclusion is right but the reasoning is not: a power bank is rated at 3.7V cell capacity, so 20,000mAh comes to about 74Wh, still inside 100Wh; at 27,000mAh you are close to the ceiling. Convert to Wh before comparing and the milliamp-hour figure will not mislead you.

The three energy bands

Rated energy Cabin allowed Requirement
Up to and including 100Wh Yes No approval needed, quantity within personal use
100Wh to 160Wh Yes, with approval Airline consent required, usually limited to two
Above 160Wh No Prohibited in the cabin and in checked baggage

The TNP-FZ100 falls in the first band, the least restricted category. Most carriers limit first-band spares to a quantity reasonable for personal use; IATA guidance is commonly twenty per passenger, individual carriers may be stricter, and their published rules take precedence. Five or six packs for a shoot rarely raises a question; a case of identical batteries invites one about what they are for.

Cabin or hold: the rule people get wrong

The distinction turns on the state of the battery. A pack installed in a camera, with the camera switched off and protected against accidental activation, can generally travel in checked baggage with the equipment. Spare packs carried separately must go in the cabin. The reason is that a short-circuit fire in the hold cannot be dealt with by the crew in time; in the cabin it can.

In practice, packing every battery into the checked suitcase is the common mistake. The correct split is one pack in the body, the rest in your carry-on bag, and power banks in the cabin as well. This holds for domestic and international flights alike, and virtually every carrier applies it.

Contact protection: what security is really looking at

The hazard in a lithium battery is the positive and negative terminals being bridged by metal at the same time. Loose in a bag with keys and coins is the textbook short circuit. Any one of three accepted measures will do.

  • Keep the original packaging, one pack per slot — factory state is the safest.
  • Tape over the metal contacts with insulating tape, or fit the supplied plastic cap.
  • Put each pack in its own zip bag or battery case so they cannot touch.

A dual-slot charging case works too: the shell isolates the contacts and the closed lid doubles as storage, at the cost of a little more bulk than loose packs. For how these accessories are used, see our dual-slot case guide.

The practical order of operations at security

  1. Before leaving, gather the batteries into one inner pocket of your carry-on rather than spreading them across three bags.
  2. Confirm every pack is protected — original box, tape or a bag — with no exposed contacts.
  3. If you are asked, say plainly that they are camera spares, and show the camera if it helps.
  4. Do not put batteries in a metal case; metal reads as a muddle on the scanner and invites a hand search.
  5. Once aboard, do not use a power bank to charge batteries; some carriers explicitly prohibit power bank use in flight.

Most of the time the X-ray shows a few neat rectangular blocks travelling with a camera, and the officer can identify them at a glance without further questions. What gets stopped is loose packs, unprotected packs and unusual quantities.

Edge cases that come up often

On a connection through a third country, local civil aviation rules apply. Most align with the standard, but a few regions are more sensitive about quantity, so on long multi-leg itineraries keep the count to four or fewer. International check-in desks occasionally ask to see the markings; a pack worn too smooth to read is easy to refuse, which is another argument for keeping the original packaging.

As for the battery’s own condition, capacity, temperature and swelling all matter. If the shell is visibly bulging before departure, do not board with it — that is a replacement signal. For more on judging battery condition and body compatibility, see the TNP-FZ100 section. If you are travelling with a full kit, the longer NP-FZ100 flight guide covers the rest.

FAQ

Will six TNP-FZ100 packs be stopped at security?

Usually not. Six come to roughly 98Wh in total, still within personal use, provided they are split across your carry-on and the contacts are protected. If you are carrying a dozen or more, it is worth preparing a commission letter or an itinerary in case you are asked.

Can batteries go in checked luggage?

Spares cannot. A pack installed in a device that is switched off and protected against activation is accepted by most carriers. When in doubt, keep it in the cabin — that choice is never wrong.

The shell is scuffed and the ratings are unreadable — can I still take it?

There is a risk of refusal. Security needs to verify rated energy and may decline carriage when the marking cannot be read. Replace the pack with one that has an intact shell, or keep the original packaging as evidence of the specification.

Can I bring a power bank and camera batteries together?

Yes. Both are managed as spare lithium batteries and both travel in the cabin. The difference is that a power bank must keep a legible capacity marking and is usually banned from use in flight; camera batteries have no in-use restriction but still cannot be checked.

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Osmo Action Long Recording, Heat and Cold Weather

Short answer: when a long Osmo Action recording fails, it is usually the body hitting thermal protection rather than the battery running flat. The three things that actually help are lower power draw, continuous power delivery and temperature control. In practice: drop bitrate and frame rate to what you need, switch off unused wireless and the front screen, run a PD power bank while recording, and keep airflow around the body. In the cold you also need insulation — below 0°C a lithium pack’s internal resistance rises, the voltage sags, and the camera shuts down.

The rest of this covers power sources, a settings checklist, power setups and cold handling, and applies to the Action 3, Action 4 and Action 5 Pro; menu names differ slightly between generations.

1. Where the charge actually goes

An action camera’s battery holds roughly a third of a phone’s, yet it has to drive stabilization, high-bitrate encoding and continuous writing, so power density is high. Ordered by impact, the main draws are:

  • Frame rate and bitrate: 4K 120fps can draw two to three times what 4K 30fps does, and heat climbs sharply, often triggering a throttle or stop within minutes.
  • Electronic stabilization: continuous cropping and computation is a standing load on the processor. Turning it off, or using a lower setting, saves a clear amount.
  • Screens, front and rear: two panels running during a long take is a significant share. Dimming them and shortening the timeout pays off directly.
  • Wireless: Wi-Fi monitoring and Bluetooth remote are easy to leave on outdoors, and running them for hours drains steadily.
  • Ambient temperature: heat reduces cooling efficiency so the body protects itself sooner; cold shrinks usable capacity. Both directions cut recording time.

This matters because simply carrying another battery does not solve “it stops at 20 minutes” — the limit is temperature, not charge.

2. A settings checklist for long takes

If the goal is continuous recording rather than maximum image quality, work through these in order; they usually extend usable time considerably:

  1. Drop resolution and frame rate to what you need: 4K 30fps or 2.7K 60fps covers most documentation, with a clear step down in both heat and draw.
  2. Turn off stabilization you do not need: on a fixed mount or a car rig, switch it off and enable it only for handheld work.
  3. Dim the screen and shorten the timeout: if you are not watching it, let it go dark quickly.
  4. Disconnect Wi-Fi and Bluetooth: enable them only for monitoring or offloading.
  5. Leave airflow around the body: avoid wrapping it in clothing or helmet padding, and prefer a metal mount over plastic for heat transfer.
  6. Record in segments: keep takes to 10-20 minutes with a deliberate cooling gap, which is more reliable than running until protection stops you.

Stacked together, these usually gain more than an extra battery. Segmented recording matters even more for clip safety than for runtime — file corruption from a mid-take power loss is not rare on action cameras.

3. Power on location: three typical setups

Different shooting styles call for very different power arrangements. The comparison below is organised by scenario.

Scenario Recommended power Watch out for
Fixed-position long takes (interviews, livestreams, in-car) PD power bank + long cable, charging while recording Choose a PD-capable, stable-output model; the cable must carry both data and current, and a poor one will drop voltage
Handheld moving work (vlogging, hiking) Body battery + 2-3 spares rotated Keep spares against your body, away from keys and other metal
Cycling, skiing, water sports Body battery, no external cable Cables compromise sealing and mounting security; carry more packs instead

Charging while recording has one precondition: the body runs warmer because of the charging, so in hot conditions protection trips sooner. That makes this approach suitable for environments with airflow, air conditioning or water cooling, not sealed hot spaces. Power bank performance also drops in the cold, so in winter an inside pocket beats hanging it off the outside of a pack.

Spare count can be roughly one pack per hour, adjusted for whether you are charging while recording. Third-party packs such as YO’s are made in versions per camera generation, so confirm the match when buying. The Action 3/4 and Action 5 Pro batteries are not interchangeable; the mapping is on the Osmo Action battery category page.

4. Cold-weather drain: why and what to do

In the cold a lithium pack’s electrolyte thickens, internal resistance rises and the usable capacity falls. The typical symptom is a jump from 40% straight to 5% and a shutdown, followed by a partial “recovery” once warm. That is normal physics, not a failed battery. The Action series is officially rated to operate at roughly -20°C, but usable time is still markedly shorter than at room temperature.

There are four responses: keep spare packs in an inside pocket at 10°C or above; let the body and battery equalise in temperature before shooting rather than carrying the camera straight from a warm room outdoors; lower frame rate and brightness to reduce instantaneous current; and do not charge immediately afterwards, waiting until everything is back at room temperature to avoid internal condensation. For a more detailed cold-testing method, see our minus 10°C battery test.

If you travel or fly to shoot locations often, it is worth checking lithium transport rules in advance; the logic in whether camera batteries can fly applies equally to action camera packs.

FAQ

How long can an Osmo Action record continuously?

Officially, under ideal 25°C conditions, the figures are about 160 minutes maximum for the Action 3/4 and up to 4 hours for the Action 5 Pro. Real continuous recording typically lands at 60-70% of that, less with high frame rates, heat or stabilization, and it often stops on thermal protection before the battery is empty.

Does charging while recording damage the battery?

Short-term impact is limited, but sustained charging at high temperature accelerates ageing. Use it in a well-ventilated, reasonably cool place, avoid running maximum bitrate and fast charging at the same time, and leave the body thermal headroom.

What can I do about fast drain in winter?

Warm the pack to above 10°C before fitting it, carry spares against your body, and put the camera back in an inside pocket between takes. Cold-induced jumps usually recover partially on warming, but repeated deep discharge shortens life, so carry one or two extra packs in winter.

Can third-party batteries handle long recordings?

Yes, but choose ones that name the specific camera generation and include a temperature-sensing contact. Long recordings demand stable discharge, and packs with inflated capacity claims tend to sag in the later stages and shut down earlier than a first-party battery.

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Why the R5, R6 and R7 Need LP-E6NH, Not LP-E6N

Short answer: the R5, R6, R7 and R6 II all ship with an LP-E6NH, which is rated for 3.0A of continuous discharge. The earlier LP-E6 and LP-E6N have no such margin. Fitted with a low-drain pack, these bodies trip their protection during peak loads such as high-bitrate recording and burst buffer writes, showing up as slower bursts, errors or a straight shutdown. The pack has not failed; it simply cannot supply the current being asked of it.

Most people fixate on mAh and reason that 1865mAh against 2130mAh is only 14%, so it will do. What actually decides whether a pack works in these bodies is a different figure: continuous discharge current. Capacity decides how long you can shoot; discharge decides whether you can shoot at all.

Why discharge current is a hard threshold

A lithium-ion pack’s voltage sags under load, and the sag equals current multiplied by internal resistance. At light loads the drop is negligible; when the body suddenly calls for 5A or 6A, a high-resistance cell falls below the protection threshold and the camera concludes the pack is empty.

The pattern has a few signatures: the gauge still shows two or three bars and the camera shuts off; powering back on gives another few dozen seconds; a recording stops partway with a battery error. Many people assume a contact problem and clean the terminals repeatedly, which achieves nothing, because the cause is cell resistance rather than the interface.

Capacity and discharge capability are separate properties. A 2130mAh cell with high internal resistance looks good on paper and performs worse under load than a 1865mAh original E6N. This is also why identical capacity can carry very different prices: the difference is nearly always in the cells.

How the loads differ across bodies

Body Heavy-load situations Recommended pack Behaviour on E6N or earlier
EOS R5 8K 30p, 4K 120p, RAW video LP-E6NH (E6P also works) High-bitrate modes limited or will not start; burst rate drops
EOS R6 4K 60p oversampled, 20fps bursts LP-E6NH Will shoot, but long takes hit heat and power cutoffs earlier
EOS R6 Mark II 4K 60p, 40fps bursts, pre-capture LP-E6NH (E6P needs a firmware update) Some high-speed functions limited; buffer writes slower
EOS R7 4K 60p, 30fps bursts, in-body stabilisation LP-E6NH Noticeably shorter runtime; slower write-back after bursts

The R5 is the most demanding of the group. 8K and 4K 120p draw far more power and current than ordinary recording, and the body actively checks what the pack can deliver. The R6 and R7 are more tolerant: an E6N will power on and shoot, but you will meet thermal protection and jumping charge levels sooner. The R7, with continuous in-body stabilisation, is also sensitive to voltage stability.

One point that gets overlooked: bursts place demand on discharge capability as well. During 20fps or 30fps sequences the sensor, processor and card are all at full load, and the instantaneous current is comparable to video recording. So even for stills only, a low-drain pack can leave you feeling that the burst stalls after a second or two.

Spotting a third-party high-drain pack

The original E6NH’s specification is unambiguous; third-party products are where the trouble starts. Plenty of listings claim “fits LP-E6NH” and very few state a continuous discharge current. Filter with the following:

  • Is a discharge current stated? A clear 3.0A or higher at least shows the maker knows what question has to be answered. Capacity alone usually means an ordinary cell in a moulded shell.
  • How does it behave in continuous recording? Fit it to an R5, shoot 8K or 4K 120p, and see whether ten minutes pass without an error and with a smooth decline. Anything that trips mid-take is out.
  • Feel the temperature. Warm after a take is normal; too hot to hold is not. Excess heat means high internal resistance, with energy going into heat instead of the recording.
  • Watch the curve. A healthy pack falls evenly from 100% to 20%. One that drops slowly at first and then jumps from 40% to 5% is padding its estimate.

YO builds the LP-E6 series to a 2130mAh specification, and the same four checks are worth running yourself rather than trusting the packaging. Packs are consumables, but a verification method lasts for years.

Four practical habits

  1. Do not run to shutdown. Repeated deep discharge accelerates capacity loss. Swap at the last bar, especially before an important shoot.
  2. Rotate packs. Alternating two packs balances wear and stops one sitting at full charge for months.
  3. Use external power for long recordings. For fixed-position interviews, streams and conferences, a dummy battery or USB-C PD supply is more stable and reduces body heat. The approach in this FX3/FX30 video power setup applies here too.
  4. Carry an extra in the cold. Below freezing internal resistance rises and usable capacity shrinks; the records in this minus 10°C battery test show how far. Keep spares against your body and swap only when needed.

If you are still weighing whether to save money with an E6N, do the arithmetic this way: one important shoot lost to a mid-take power failure costs far more than the difference between two packs. The logic in this range differs from that of small LP-E17 bodies: there, capacity carries more weight because loads are light; here, discharge capability comes first.

FAQ

What is the difference between E6NH and E6P on an R5?

Both are 2130mAh; the E6P is rated 6.0A continuous discharge against the E6NH’s 3.0A. An E6NH already supports every function on the R5, and moving to an E6P mainly adds margin and slightly lower heat — no extra features unlock. Where the price gap is large, the E6NH is the better buy for an R5.

A third-party pack claims 2130mAh and is very cheap. Will it work?

Ask whether it dares to state a discharge current. Capacity alone usually means an ordinary cell that will drop out under the R5’s high-bitrate modes. Buy one and stress-test it before ordering more; do not buy four at once.

Why is a fully charged pack flat after a week?

First check whether it was left in the body. A camera on standby still draws power, so remove the pack for long gaps. If it still loses half its charge in a week when removed, self-discharge is abnormal or the protection board is leaking, and the pack should be replaced.

Should I worry about a warm pack?

Warm after a long take is normal. Too hot to hold, slight casing deformation, or an odd smell — any one of those means stop at once and isolate it. Do not put it back in a camera, do not keep charging it, and dispose of it through battery recycling. More fault diagnosis is in the LP-E6 section.

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Can You Fly with NP-FZ100 Batteries? TSA and FAA Rules

The direct answer: yes, you can fly with them — and they have to come in the cabin with you, not in checked bags. The NP-FZ100 is rated 7.2V / 2280mAh for roughly 16.4Wh, comfortably under the 100Wh threshold. Under TSA and FAA guidance, loose spares belong in carry-on only; putting them in checked luggage is prohibited. A battery installed in your camera travels with the camera. Spare terminals need short-circuit protection — original packaging, a terminal cover, or insulating tape — and some airlines impose a per-person limit on how many you may bring. Carriers apply the rules with some variation, so confirm details with the airline before you fly. Below: the rules, how to pack, and how many to carry.

The number that matters: 16.4Wh

Aviation rules classify lithium batteries by watt-hours (Wh), not milliamp-hours:

  • Under 100Wh: spares allowed in carry-on. Airlines commonly cap the count at around twenty per person.
  • 100–160Wh: airline approval required in advance, with a lower per-person allowance. Typical of large camcorder bricks.
  • Above 160Wh: prohibited.

At roughly 16.4Wh, the NP-FZ100 falls squarely in the most relaxed bracket. The math is Wh = capacity (Ah) × voltage (V): 2.28Ah × 7.2V ≈ 16.4Wh. The 2400mAh variant works out to about 17.3Wh, still nowhere near 100Wh. How to read those figures is covered in what mAh, Wh, and V mean.

Three non-negotiables

1. Spares go in carry-on, not in the hold

An installed battery stays with the camera; every loose spare goes in your cabin bag. The reasoning is straightforward: if a cell goes into thermal runaway in the cargo hold, nobody can reach it quickly. Security finding loose lithium cells in a checked bag will typically pull the bag for inspection.

2. Protect the terminals

Metal contacts touching keys, coins, or another battery can short. Three accepted methods:

  • Keep them in the original retail packaging — easiest and most common;
  • Fit terminal covers or snap them into a plastic battery case;
  • Tape over the contacts with insulating tape, or use a divided storage wallet.

3. Quantity limits follow your airline

Most carriers set an internal cap — commonly around twenty spare batteries per person under 100Wh — and some are stricter, with higher counts requiring advance notice. There is no single universal figure; check your airline’s website or call. On crew trips, split packs across team members rather than concentrating them with one person.

Getting through security without friction

  • Out of the bag. Put the battery wallet in a tray on its own to reduce the odds of a manual search.
  • Keep markings legible. Capacity and voltage printing should be readable; worn labels are worth re-marking before you travel.
  • Separate camera and spares. Leave the installed pack alone, but carry spares separately.
  • Say it plainly. “Camera lithium batteries, about 16.4Wh, spares in my carry-on” answers most questions in one sentence.
  • Keep them with you. Don’t wedge spares into gaps in an overhead bin where they can be crushed.

How many to bring, by trip

Trip type Suggested count Notes
City break, light shooting One in the body plus one or two spares No issue in carry-on at all
One week, daily shooting Three or four plus a dual charger Recharge at the hotel, rotate through the day
Polar, altitude, or cold destinations Five or six Cold may leave you around half capacity
Commercial crew travel Confirm the cap with the airline first Split across people, carry a spec sheet

One more thing that trips people up: chargers and power banks ride in the cabin too. A power bank counts as a spare battery, is banned from checked luggage, and must have its capacity printed on the case.

Onboard handling

  • Charging during the flight isn’t recommended, particularly through unfamiliar in-camera charging features.
  • Keep packs away from pressure, bending, and loose metal objects.
  • Swelling, leakage, odor, or unusual heat means stop. Don’t use it, don’t fly with it, and route it to recycling.
  • On arrival, bring batteries up to working charge before heading out, and leave extra margin if temperatures are low.

FAQ

Do I need to declare NP-FZ100s to the airline ahead of time?

Usually not for batteries under 100Wh, though the quantity cap still applies. Carrying a lot, or flying a carrier with explicit requirements, means calling before departure.

Does the battery inside the camera count as a spare?

No. A pack installed in equipment travels as part of that equipment. Only loose batteries are treated as spares, with the carry-on and terminal rules attached.

Can I fly with a swollen battery?

Don’t, and don’t keep using it either. It belongs in a hazardous waste or recycling stream — see what to do about a swollen battery.

Are international rules different?

The framework is similar everywhere — Wh-based tiers, spares in the cabin — but specific caps and enforcement vary. On international itineraries, check both your departure and transit carriers.

Do power banks count toward my battery total?

Depends on the carrier, but they’re carry-on only and must be labeled with capacity. Video shooters hauling large banks should confirm before the trip.

Bottom line and travel checklist

Three sentences to remember: 16.4Wh sits well under 100Wh; spares ride in carry-on and never in the hold; protect the terminals and confirm quantities with your airline. Before you go, put everything in a purpose-made battery wallet, screen it separately, and keep a small card noting the spec (7.2V / 2280mAh / about 16.4Wh). Need more packs before the trip? YO’s NP-FZ100 compatible battery is around $17.89, about $22.93 with one battery and a charger, and about $36.74 for two with a charger. The TNP-FZ100 (2400mAh / about 17.3Wh) adds headroom at around $19.66, or about $39.92 as a two-battery kit; Sony’s original runs $70 and up. More quantity-planning logic is in one battery or two. Studios, rental houses, and resellers needing 100 units or more should request pricing via the wholesale inquiry page.

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NP-F Runtime Math for Monitors and LED Panel Lights

Short answer: estimating how long an NP-F pack lasts needs one formula — runtime in hours ≈ battery Wh × 0.85 ÷ device wattage. The 0.85 accounts for conversion losses in step-up and step-down regulation, and Wh = nominal 7.2V × capacity in Ah. An F970, for example, is 7.2V × 6.6Ah = 47.5Wh; driving an 8W monitor, 47.5 × 0.85 ÷ 8 comes to about 5 hours. Learn the formula and you can work out any device yourself instead of guessing.

1. First, convert mAh to Wh

The 6600mAh printed on a pack describes charge, not energy. At the same 6600mAh, a 7.2V battery holds twice the energy of a 3.6V one. Any comparison across devices has to be made in Wh.

The conversion is simple: Wh = voltage (V) × capacity (Ah), where Ah = mAh ÷ 1000. Every NP-F pack is 7.2V, so you just divide the capacity by 1000 and multiply by 7.2.

Model Nominal capacity Voltage Energy (Wh)
NP-F550 About 2200mAh 7.2V About 15.8Wh
NP-F570 About 2600mAh 7.2V About 18.7Wh
NP-F750 About 4200mAh 7.2V About 30.2Wh
NP-F770 About 5000mAh 7.2V About 36Wh
NP-F960 About 5600mAh 7.2V About 40Wh
NP-F970 6600mAh 7.2V About 47.5Wh

One useful reference point: civil aviation allows lithium batteries up to 100Wh in carry-on without declaration, and the F970’s 47.5Wh is barely half of that, so carrying two or three is comfortably within the rules. For the declaration thresholds and quantity limits, see the rules for flying with lithium batteries.

2. Second, confirm what the device actually draws

The usual mistake in runtime estimates is not the formula but the wattage you put into it. Manufacturers’ “maximum power” and “typical draw” often differ by a factor of two. The ranges below are real-world starting points.

Device type Typical draw Notes
5-inch monitor (400-500nit) About 4-6W Moderate brightness, no internal recording
7-inch high-bright monitor (1000nit+) About 8-12W The bright panel is the main load
Wireless video receiver About 3-5W Add to the monitor figure
Small LED panel About 10-20W Varies with brightness setting
High-output LED spotlight About 25-40W At full power, close to the pack’s output ceiling

When no rating is given, there is a rough workaround: take the input current from the manual and multiply by the voltage. A 12V / 0.7A rating works out to about 8.4W. If the manual only says “NP-F970 recommended”, that usually means the draw is mid-to-high and a small pack will hit low-voltage cutoff quickly.

3. Third, run the numbers into a schedule

Feed the first two steps into the formula. The table below already applies the 0.85 efficiency, so it can be used directly for planning.

Device draw F550 (15.8Wh) F750 (30.2Wh) F970 (47.5Wh)
5W monitor About 2.7 hours About 5.1 hours About 8.1 hours
8W monitor About 1.7 hours About 3.2 hours About 5.0 hours
15W panel light About 0.9 hours About 1.7 hours About 2.7 hours
30W spotlight About 0.4 hours About 0.9 hours About 1.3 hours

When scheduling, take another 20% off the result. The reasons are in the next section. In other words, an F970 running an 8W monitor should be planned at 4 hours, not 5.

  1. List every load: if a monitor, a video transmitter and a follow-focus share one pack through a D-tap or splitter, add the wattages together.
  2. Calculate at the highest setting: light output gets adjusted, but the schedule has to assume the brightest setting you might use.
  3. Convert to hours per pack: write the result on a label on the battery so nobody recalculates on set.
  4. Size the count to the day: total hours ÷ hours per pack, round up, then add one spare.

4. Four things that throw the estimate off

The formula gives a theoretical figure, and reality always drifts. Knowing where the drift comes from lets you build in margin ahead of time.

  • Inflated capacity claims: a cheap pack labelled 8000mAh in the same shell as an F970 usually delivers around 5000mAh. Volume sets a physical ceiling on the cells, and labels beyond common sense are not credible.
  • Cold: usable capacity drops noticeably below 0°C, and at -10°C it may be only 60-70% of room-temperature figures. On winter shoots, keep packs in an inside pocket and fit them only when needed.
  • Voltage sag at the end of discharge: a lithium pack’s voltage falls quickly over the last 10%, and many devices trip low-voltage protection early, so usable capacity ends up below the nominal rating.
  • Conversion losses rise with current: efficiency drops below 0.85 at high current; when powering a 30W device, 0.8 is closer to reality.

There is one more point that often gets missed: for LED lights, continuous discharge capability matters more than capacity. Small packs sag badly under high current, which produces the “40% left but the light will not strike” situation. That is exactly why high-output lights are generally paired with an F970 rather than an F550.

If what you need is long-term power for a mirrorless body rather than for monitors and lights, the approach is different: the body’s compartment uses a dedicated adapter, which means a dummy battery setup — see NP-FZ100 dummy battery power for the form it takes. YO’s NP-F range is conservative about capacity figures, so the calculated times generally match real use, which suits anyone scheduling by these methods. For more on the model tiers, see the NP-F960 / F970 category page.

FAQ

Why can’t I compare runtime using mAh?

Because mAh measures charge only and ignores voltage. A 7.2V 6600mAh pack holds twice the energy of a 3.6V 6600mAh pack. Only after conversion to Wh are packs at different voltages comparable.

What is the 0.85 in the formula?

It is conversion loss. The pack outputs 7.2V while the device may step up to 12V or regulate down to 5V internally, and part of the energy becomes heat along the way. Most devices land between 0.8 and 0.9, so 0.85 is a reasonable general compromise.

Why does the monitor’s remaining-time reading differ from my calculation?

Most monitors estimate remaining charge from voltage, and a lithium pack’s discharge curve is very flat through the middle, so the error is large. The display shows an approximate ratio for the current voltage, not true remaining energy. Timing by the clock is more reliable than watching a percentage.

Can two packs in parallel extend runtime?

Yes, with conditions. Parallel operation requires closely matched voltage and internal resistance; mixing old and new packs causes uneven current sharing, and the weaker pack drags the pair down. Proper dual-battery plates usually include isolation circuitry, which a plain splitter does not.

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Nikon Z fc Battery and USB-C Charging Explained

Short answer: the Z fc uses an EN-EL25 battery (7.6V / 1120mAh / about 8.5Wh), the stock charger is the MH-32 dock, and the body has a USB-C port. The most dependable everyday setup is the dock plus one spare. On the road, a USB PD power bank into the body’s USB-C port is a useful supplement for light travel, but it depends on supply wattage and cable quality — plugging in does not guarantee fast charging.

The Z fc’s retro styling makes it easy to underestimate how modern the camera is. It shares its sensor and processor with the Z50 and has a similar power profile, but because the port moved from Micro-B to USB-C there are far more ways to charge it. Choose well and it is effortless; choose badly and it feels as though the camera will not take a charge.

Battery specs and real-world runtime

The EN-EL25 is a small cell at roughly 8.5Wh, half the energy of the full-frame EN-EL15c. The Z fc is an APS-C body with a lighter processor load, though, so frame counts do not shrink in proportion. The CIPA figure sits around 300 shots, and real use tends to land between the low 200s and the mid 300s.

Three things dominate Z fc runtime:

  • EVF or screen. The electronic viewfinder keeps the sensor reading out at continuous high speed, which draws noticeably more than the tilting screen. Street shooters who habitually raise the camera to the eye should plan for the lower end.
  • Dial operation, indirectly. ISO, shutter speed and exposure compensation are all physical dials on the Z fc, so adjusting them does not light up the screen. That actually saves power.
  • Wireless. SnapBridge left running with auto transfer drains the battery in the background. Switch it off when you do not need it.

A related point: the Z fc has no in-body stabilization, which also makes it a little more frugal than the full-frame bodies in the same family. The trade-off is that slow shutter speeds handheld depend on lens VR or a faster shutter.

Three charging routes compared

Route What you need Approx. full charge Best for Watch out for
MH-32 dock Stock dock + wall outlet Around 2 hours Home, hotel overnight Most reliable; stricter about third-party packs
In-body USB-C PD-capable supply + C-to-C cable About 2-3 hours Outdoors, car, café Depends on wattage and firmware; faster with the camera off
Power bank 18W or higher PD bank Depends on capacity Long shoots, travel Compare in Wh; check airline limits

The times above are empirical ranges and will drift with ambient temperature and battery condition. Slower charging in the cold is normal: the battery management system lowers current deliberately to protect the cells.

Four pitfalls of USB-C charging

1. The charger does not support PD

Plenty of older chargers have only a plain 5V/2A USB port. The camera will detect power and start charging, but the current is tiny — a whole night may add only a little. The quick test is the label: look for a 9V or 12V output step. If there is one, it is PD.

2. The cable is a charging cable, not a data cable

Some budget USB-C cables wire up only the power pins and omit the full communication lines, so the camera and the supply never negotiate a higher profile and fall back to 5V. Swapping in a C-to-C cable rated for 60W or 100W usually solves it.

3. Not enough power while shooting

With the camera on, the body’s own consumption is served first and only the remainder goes to the battery. If the power bank outputs 18W and shooting draws close to that, the level barely moves. To gain charge while shooting, budget 30W or more of headroom.

4. Cold-weather protection

Below freezing the body may refuse to charge outright, or stop at some percentage. That is a protection mechanism, not a fault. Warm the battery against your body first, then charge. For how cold affects discharge, see our minus 10°C battery test; the mechanism is common to every brand.

What to pack

  1. Decide whether the dock comes along. For a single day in the city, two EN-EL25 packs are plenty and the dock can stay home. For trips of two or three days or more, bring the MH-32 for peace of mind.
  2. Pick a power bank of 10000mAh or more with 30W PD output. That spec refills the body two or three times and the weight is still reasonable.
  3. Budget one battery per 250 shots. Lean lower if you use the EVF a lot, higher if you mostly compose on the screen.
  4. Spares need not be expensive. Third-party EN-EL25 packs are usually inexpensive; pick one labelled 7.6V / 1120mAh that names the Z fc explicitly. Brands such as YO that list supported bodies make the comparison straightforward.
  5. Check airline rules before you fly. Lithium batteries must stay in the cabin, not checked baggage, and limits on capacity and quantity vary slightly by carrier — see whether camera batteries can fly.

The Z fc’s battery ecosystem is simple: one EN-EL25 plus a dock covers the vast majority of situations. For a side-by-side look at sibling bodies, the EN-EL25 category page compares Z50 and Z30 runtime.

FAQ

Can I charge the Z fc with a phone charger?

Yes, if the charger supports USB PD and has enough wattage. A plain 5V slow charger will usually only maintain the current level and charge very slowly. Use an 18W-or-higher PD charger with a good-quality C-to-C cable.

Can the Z fc shoot while charging?

Usually yes, but whether the level rises depends on supply wattage and the current shooting load. Video draws more; an 18W supply may only hold the level steady. If you want the charge to climb while shooting, 30W or more is the realistic target.

Are the EN-EL25 and EN-EL15 interchangeable?

No. They run at 7.6V and 7.0V respectively and differ in size, so one physically will not fit where the other belongs. The Z fc takes only the EN-EL25 or EN-EL25a.

What if a battery left unused for months will not charge?

First check whether it was stored flat for a long time, which can over-discharge it. Try seating it in the dock and reseating it a few times to wake it. If there is still no response, the cells have gone into protection and the pack should be replaced. For daily storage, keep about 60% charge and top up every three to six months.

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Why NP-W235 Fits Both the Fujifilm X-T4 and X-T5

Short answer: the X-T4 and X-T5 use the same NP-W235 pack, so batteries are fully interchangeable, chargers are shared, and moving from an X-T4 to an X-T5 requires no new batteries. The NP-W235 and NP-W126S, by contrast, cannot be mixed — both are 7.2V, but the physical dimensions, compartment structure and contact positions are completely different, so one will not physically go into the other’s body. In other words, batteries do not carry across generations, and within a generation compatibility is conditional — that is the real shape of Fujifilm’s battery system.

“Same voltage means it works” is the most common misconception in questions like this. The relationships break down layer by layer below.

1. Three relationships, sorted out first

Body Battery model Interchangeable with
X-T4 NP-W235 X-T5, X-H2, X-H2S, X-S20, GFX series
X-T5 NP-W235 As above
X-T3, X-T30 II NP-W126S X-T2, X-Pro3, X-E4, X100V, X-S10, X-H1
X100V, X-E4 NP-W126S As above

The dividing line is very clear: fourth-generation bodies, starting with the X-T4, moved to the NP-W235, while third-generation and earlier bodies use the NP-W126S. Nothing crosses that line.

2. Why W235 and W126S cannot be mixed

Different size and compartment. The NP-W235 is distinctly larger than the NP-W126S, and the compartment depth, width and latch position were redesigned for it. Drop a W126S into an X-T5 and it sits loose and will not lock; push a W235 into an X-T3 and it will not go all the way down.

Different contact layout. The positive, negative and communication contacts sit in different places on the two packs, so even forced contact will not establish a stable connection. The body’s detection logic will simply report no battery or a battery error.

Different discharge capability. The NP-W235 holds about 1.7 times the capacity of the NP-W126S, and the X-T5 and X-H2 processors and stabilization systems are designed around higher continuous current. Running a high-draw cell in an older body would serve no purpose — and physically it cannot happen anyway.

Chargers are not shared. The NP-W235 uses a dock such as the BC-W235, whose slot shape is entirely different from the W126S charger. Mixing them fails at the physical level, which conveniently rules out the mistake.

The body adds another layer of foolproofing. Locating ridges inside the compartment correspond one-to-one with recesses on the pack, so even if someone forces a battery in at an angle, the latch will not close and the body will not power up. The design intent is to make “wrong battery” impossible rather than to rely on users remembering rules.

Contact condition affects this too. On a well-used pack, oxide or wear appears on the contact surfaces, showing up as an occasional failure to power on that needs a reseat. Rubbing the contacts with an eraser is an emergency fix; do not scrape them with a blade, because removing the plating makes oxidation faster.

3. Even within a generation there are exceptions

Sharing the NP-W235 does not mean every accessory carries over. The X-T4 supports a vertical grip that holds two more W235 packs, giving a three-battery system; the X-T5 dropped grip support, so an X-T4 grip cannot be used on it. If you relied on the grip for endurance, that shortfall has to be covered with spare packs after the upgrade.

Charging differs as well. The X-T5 and X-H2 support USB-C in-body charging, while the X-T4’s USB-C port is mainly for data transfer and charging still depends on the dock. On a business trip that directly changes how many chargers you pack.

Also, because both bodies use the same pack, mixing packs in different health states makes the camera report the weaker one. Before a long recording, try to keep the cycle counts of the two packs close. A fitment list for related models is on the NP-W235 category page.

4. Dealing with old batteries when you upgrade

  1. X-T3 to X-T5: none of the old W126S packs will work. Selling them with the old body is better value than hoarding them.
  2. X-T4 to X-T5: keep every battery and the charger. You only need one new pack to cover the endurance the grip used to provide.
  3. Running two systems: an X-T3 plus X-T5 combination needs two sets of batteries and two chargers, which adds bag weight. Work it out before the trip.
  4. Disposing of old packs: do not resell swollen or clearly degraded batteries — take them to a lithium battery recycling point.

If you are still on a W126S body, the recommendations are on the NP-W126S category page. A YO NP-W235 compatible pack works well as a spare for the X-T4 and X-T5, while the primary slot is still best left to a first-party pack, especially for continuous recording.

Watch the model labelling in used sales too. Some sellers bundle a W126S body with a W235 battery, and the buyer only finds out at home. Before paying, ask for a straight-on photo of the battery label and check the model and capacity — that is more direct than trusting the body’s model number.

FAQ

Can an X-T4 battery go straight into an X-T5?

Yes. Both bodies use the NP-W235, and batteries and chargers are interchangeable with no adapter needed.

NP-W235 and NP-W126S are the same voltage, so why are they not compatible?

Voltage is only one parameter. The external dimensions, contact positions and compartment structure all differ, so it cannot physically be fitted and the body cannot recognise it.

Can the X-T5 use a grip to extend runtime?

No. The X-T5 does not support a vertical battery grip, so extra runtime has to come from spare packs or USB-C power.

Does a third-party W235 affect burst speed?

Usually it does not directly change the burst frame limit, but unstable voltage can cause the frame rate to drop mid-burst or trigger an early warning. For important work, use a first-party pack in good condition.

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“LP-E6: Swelling, Fast Drain and Unreadable Packs”

Short answer: a swollen LP-E6 must come out of service immediately. It cannot be repaired and it must never be punctured to vent gas. Fast drain is usually a rise in internal resistance from aged cells, cold conditions or long storage at full charge. When the body refuses to recognise a pack, check contact oxidation and the decoder circuit first. Each of the three has a completely different remedy, so identify which one you have before deciding to repair or replace.

All three share one trait: none of them happens suddenly. Swelling is usually preceded by long periods stored full or used in high heat; fast drain is often preceded by charge levels that jump; a pack the body will not read has often been dropped, exposed to water, or left with blackened contacts. Watching for those early signs is far more useful than reacting afterwards.

Swelling: the only correct response is to stop

The physical cause of swelling is gas generation inside the cell. Overcharging, over-discharging, high heat and simple ageing all break down the electrolyte and release gas, which pushes the foil pouch out and bows the casing. The process is irreversible, and no household method reverses it.

How to check. Lay the pack flat on a table or a sheet of glass and press gently on the corners. If it visibly rocks or lifts, it has swollen. If it feels tighter than usual going into the body, or the door needs force to latch, suspect swelling too. A slight bulge is invisible to the eye but changes how the pack seats.

Three things never to do. Do not pierce it to release gas — lithium reacts violently with air. Do not put it in a freezer — condensation inside raises the short-circuit risk. Do not put it back in the camera to “use it a few more times”. None of these is excessive caution; each is a common origin of real incidents.

What to do instead. Stop using it, cover both terminals with insulating tape, keep it alone in a metal container away from anything flammable, and get it to a hazardous-waste point or battery collection bin promptly. Do not put it in household rubbish and do not leave it sitting at home for months.

One related note: if a swollen pack is already jammed in the bay, do not lever it out with tools. Take it to a repair centre — damaging the bay or puncturing the cell both cost more than a new battery.

Fast drain: rule out the environment, then suspect the cell

Symptom Most likely cause How to check What to do
Full pack drops to half in a week Standby drain inside the body Remove it and repeat the week Take the pack out when not in use
Drains very fast outdoors in winter Cold raises internal resistance See whether charge partly returns once warm Keep spares against your body
First 70% is fine, last 30% shuts down Aged cell, steeper voltage curve Watch whether it repeats Replace the pack
A new pack is worse than the old one Overrated capacity or poor cells Compare charge time and heat Return it, buy one with clear ratings
Gauge jumps from 3 bars to 1 Inaccurate decoder estimate Run a full charge/discharge calibration Replace if calibration does not help

Cold deserves separate treatment. Below freezing, electrolyte viscosity rises and lithium ions move more slowly, so usable capacity shrinks — you see two bars left and a warning after a handful of frames. The pack is not broken; capacity partly returns once it warms up. For how much is lost at different temperatures, the data in this minus 10°C battery test comes from another pack, but the trend is the same.

A pack the body will not read: start at the contacts

When the body reports a communication error or an unrecognised battery, work through the following in order. Eight out of ten cases are solved by the first two steps.

  1. Clean the contacts. Take the pack out, rub the terminals and the metal tabs inside the bay with a clean pencil eraser, then wipe with a cotton swab and anhydrous alcohol, let it dry and refit. Oxide layers and fingerprint grease are the most common cause.
  2. Cross-check with another pack. Fit a known-good pack into the same body. If it behaves, the original pack is the problem; if the error persists, the fault is in the body contacts or firmware.
  3. Check the firmware. Some bodies change how they handle third-party packs after an update. If you upgraded recently and the pack used to work, read the official release notes first.
  4. Check for water damage or a drop. Corrosion on the protection board after moisture, or cracked solder joints after a fall, both break communication. Damage of that kind usually comes with a deformed casing or an odd smell.

If cleaning and cross-checking both fail, the decoder circuit inside the pack has failed. Such a pack will often still supply power, but the body cannot read its charge and treats it as unknown. That is acceptable for unimportant work, but do not take it out for anything that matters — you have no way to predict how much is left.

Making one last longer

  • Do not store packs at full charge. Around half is the most stable state; top up before you go out.
  • Do not run them to shutdown. Swap at the last bar, because deep discharge damages the cell cumulatively.
  • Avoid heat. Do not leave packs in a car in summer, and do not charge them on a duvet or a sofa.
  • Use a matching charger. The LC-E6E will charge all four LP-E6 generations; unbranded chargers with inaccurate cut-off voltages are a common cause of swelling.
  • Run a full charge and discharge every so often so the body can recalibrate its curve — every three to six months is enough.

For how the four generations differ in capacity and discharge, see the LP-E6 family section. Owners of smaller bodies face the same logic but a different pack, covered in the LP-E17 section.

FAQ

Can a slightly swollen pack still be used?

No. Swelling means gas has formed inside and the casing has lost mechanical strength; continuing to charge and discharge risks rupture and fire. “Slight” only means it is not yet visible — a tighter fit in the bay is already the signal. Retiring it is the only recommendation.

Does fast drain mean the pack is failing?

Not necessarily. Rule out three external factors first: was it left in the body on standby, was it used in the cold, had the firmware just been updated. If none applies, run a full charge and discharge to recalibrate. Only if it still drains fast should you conclude the cells are aged.

Can a third-party pack damage the body?

A properly built compatible pack will not harm the camera in normal use. The risk comes from two kinds of product: cheap cells with no protection board, which can overcurrent, and casings with poor dimensional tolerance that are hard to insert and wear the contacts in the bay. Choosing a brand with clearly stated specifications keeps the risk manageable.

What is the safest way to store an old pack?

Charge to about half, store it separately, keep it away from metal objects and top it up every three to six months. Once a pack has swollen or leaked, treat it as hazardous waste rather than keeping it at home. Store it away from radiators, balconies and anywhere children can reach.