Month: September 2026

Long-term storage comes down to three rules: hold roughly 40–60% charge, keep it cool and dry at about 15–25°C, and top up every three months. Lithium cells self-discharge and age even while unused. Sitting at full charge accelerates capacity loss, and sitting empty risks discharging below the point where a charger will accept it again. Storage is not something you do once — it is a state you maintain.

Before storage: six steps

Step 1: bring the charge to 40–60%

• Step 1: if it is full, put it in the body and shoot for a while, or otherwise bring it down to two or three bars.
• Step 2: if it is nearly empty, charge to about half first.
• Step 3: no need for an exact percentage. Two or three bars on the body, roughly half, is fine.

Step 2: clean the contacts and shell

• Step 1: wipe the contacts with a dry soft cloth to remove fingerprints, sweat and dust.
• Step 2: confirm the contacts are not discolored or deformed and the shell is not bulging.
• Step 3: if there is any moisture, let it dry fully before sealing it away.

Step 3: protect against short circuits

• Step 1: fit the original terminal cover, or use the pack’s own cap or sleeve.
• Step 2: do not stack bare packs where metal contacts can touch each other.
• Step 3: keep them out of bags and pockets shared with keys and coins.

Step 4: choose the right spot

• Step 1: pick a cool, dry place around 15–25°C, out of direct sun.
• Step 2: away from radiators, stoves and windowsills where temperature swings, and never in a summer car.
• Step 3: in humid climates a sachet of desiccant in the storage box helps, without letting the pack touch the chemicals directly.

Step 5: set a top-up reminder

• Step 1: put a recurring three-month reminder in your phone for each pack.
• Step 2: when it fires, check the charge level and bring it back into the 40–60% band if it has dropped.
• Step 3: use a matching charger, and either unplug at full or stop around half.

Step 6: label it

• Step 1: mark the pack with purchase date and the date of the last top-up.
• Step 2: with several packs, number them so rotation and condition tracking stay simple.

Check it again when you take it out

• Step 1: look for bulging or a deformed shell. If it has swollen, stop using it and take it to a recycling or household hazardous waste point. Do not puncture or burn it — see the battery swelling and error code FAQ.
• Step 2: clean the contacts, fit it to the body, and confirm it is recognized.
• Step 3: charge it fully before heading out, and note whether runtime is markedly shorter than before storage.
• Step 4: if the gap is large, run a full cycle so the body can recalibrate. The method is in first charge and calibration.

Without maintenance, a stored pack can self-discharge to a level that causes problems. To judge whether it needs replacing, see NP-FZ100 lifespan and capacity loss.

Storage mistakes we see often

• “Full is safer”: the opposite. Long periods at 100% speed up wear. 40–60% is better.
• “The fridge is ideal”: household fridges are humid and prone to temperature swings, and condensation on the way out is a real risk. Skip it.
• “Empty costs less”: storing empty risks self-discharging below recovery, after which it may never charge again.
• “Set it and forget it”: self-discharge is real. Check at least every three months.
• “Batteries can go in checked luggage”: spares go in carry-on only, with terminals protected. Follow your airline’s rules.

Two notes on the storage environment

On temperature, “cool” matters more than “cold”. Warmer surroundings generally mean faster aging, but that is not a reason to use a fridge — the humidity and condensation risk outweigh the benefit. If you live somewhere humid, a small desiccant sachet in the box plus occasional contact checks is a reasonable routine.

On quantity, keep several stored packs in one numbered case and check them together with the three-month reminder so none gets missed. Planning the numbering and rotation at purchase time makes it easier; for bulk setups, the wholesale inquiry page is the place to start.

FAQ

What charge level is right for storage?

Around 40–60% is the common recommendation. Two or three bars on the body is close enough; there is no need to hit an exact number.

How often should I top it up?

Every three months is a good default. In warmer storage, self-discharge runs faster, so shorten the interval a little.

Is it usable after two years in storage?

It depends on how it was maintained. With regular top-ups most packs still work, though some capacity loss is likely — run a session before making it your main pack again.

Can I leave the battery in the camera?

We suggest not. Bodies draw a small standby current. Remove the pack, store it separately, and protect the terminals.

Good storage buys you an extra year or two. For rotation and spares, start with the YO NP-FZ100 compatible battery (2280mAh / 7.2V / about 16.4Wh, around $17.89); the two-battery kit at around $36.74 lets you run one while storing the other. The higher-capacity TNP-FZ100 at 2400mAh / about 17.3Wh is available too. Studios and rental houses managing stock should use the wholesale inquiry page — one batch makes numbering and scheduled maintenance simpler.

Short answer: the 12-hour first charge is a myth, and following it can do more harm than good. The advice comes from nickel-cadmium and nickel-metal hydride days, when cells had a memory effect and needed a long trickle charge to wake up. The NP-FZ100 is lithium-ion. It has no memory effect and ships with usable charge. A matching charger switches its indicator and stops output when the pack is full, so leaving it connected adds nothing but hours at 100%.

Five steps for the first use

Step 1: inspect it out of the package

• Step 1: check the shell for dents, bulges or deep scratches, and the contacts for discoloration or deformation.
• Step 2: confirm the markings on the pack match what you ordered — NP-FZ100 is 2280mAh / 7.2V / about 16.4Wh.
• Step 3: confirm the model suits your body. NP-FZ100 covers the A7 III, A7R III/IV/V, A7 IV, A7S III, A9 series, A1, A6600, A6700, A7C series, FX3, FX30 and ZV-E1. The A6400, A6500 and A7 II series use NP-FW50 — check the Sony mirrorless battery cross-reference.

Step 2: shoot first or charge first, either is fine

• Step 1: new packs usually arrive with partial charge, so you can mount and shoot. A full charge first is not required.
• Step 2: if the body says remaining charge may not display accurately, that is common and you can keep shooting. It comes from how the body estimates remaining charge.
• Step 3: for a “cannot recognize” or “cannot use” message, power down, clean the contacts, reseat, and contact support if it persists. Process in warranty and returns.

Step 3: charge normally with a matching charger

• Step 1: confirm the charger lists NP-FZ100 compatibility and that pins and sockets are snug.
• Step 2: start the charge. Slight warmth during charging is normal.
• Step 3: once the indicator turns green, unplug. There is no need for extra hours on top.
• Step 4: if it becomes hot or smells, cut power and stop using the pack.

Step 4: run a few full cycles to calibrate

• Step 1: for the first two or three uses, run from full down to the low-battery warning, then charge fully.
• Step 2: this is not about waking up the cell. It gives the body a reference discharge curve.
• Step 3: after calibration, go back to topping up as you go. Do not deliberately drain it every time.

Step 5: confirm the runtime you get

• Step 1: under your usual settings, note the frame count or recording time from full to the low-battery warning.
• Step 2: official CIPA figures usually sit between 500 and 700 frames, with real-world results commonly 60–80% of that, lower for video.
• Step 3: if the gap looks large, rule out temperature and settings, then check whether the capacity matches the label.

Why the 12-hour rule stuck around

It was not invented from nothing. It is a habit left over from an earlier technology:

• Nickel cells did need it: early rechargeables had a memory effect, and long trickle charging helped realize capacity.
• Early chargers were crude: cutoff logic was imprecise, so extra time was treated as insurance.
• Lithium is different: packs and chargers now include overcharge protection, and long periods at full charge tend to accelerate capacity loss.

Three reminders for first use

• Do not drain it on purpose: deep discharge does lithium cells no favors. Top up when the camera warns you.
• Do not leave it charging unattended overnight: unplugging when full is steadier, and lets you notice abnormal heat sooner.
• Store at half charge if it will sit: around 40–60%, in a cool dry spot at 15–25°C, topped up every three months. Details in long-term storage guidance.

If the pack sat around before first use

Treat it as stored stock first. Check for bulging, shell deformation and contact oxidation. If charge is clearly low, bring it to roughly half before shooting rather than deep-cycling it immediately. The full storage and retrieval routine is in long-term storage guidance, and telling wear from failure is covered in NP-FZ100 lifespan and capacity loss. If it has swollen, stop using it and route it to recycling — do not puncture or burn it. Dispose of it through a proper recycling point.

FAQ

How long does a new pack take to charge?

Go by the indicator. It is usually on the order of an hour or two depending on starting charge and current, and no extra top-up time is needed.

Is a part-charged new battery a defect?

No. Packs ship with partial charge so you can use them straight away. Just charge it up.

Must the first charge run until the camera shuts off?

No. A full cycle is for calibrating the body, worth doing a couple of times. Day to day, top up as you go.

Can I shoot while charging?

Some bodies accept power through their USB port, with charging speed and heat varying by model. For long recording, a dummy battery with an adapter is steadier — match voltage and connector.

For a new pack, the order is simple: confirm recognition, charge normally, calibrate over the first few cycles. For spares or rotation, the YO NP-FZ100 compatible battery (2280mAh / 7.2V / about 16.4Wh, around $17.89) and the two-battery kit at around $36.74 cover most setups, and the higher-capacity TNP-FZ100 at 2400mAh / about 17.3Wh suits video users. Studios and rental houses ordering 100 units or more should use the wholesale inquiry page.

An NP-FZ100 commonly retains around 80% of its capacity after 300–500 cycles, and that number is not fixed — habits push it either way. What works is not complicated: keep the pack out of extreme charge states, out of heat, and out of long storage without attention. Below are five habits, ordered by how easy they are to adopt, each with steps.

Habit 1: top up early, avoid deep discharge

Lithium cells have no memory effect, so there is no need to empty them first. Running to zero repeatedly does more harm than good.

• Step 1: charge after a session rather than waiting for the low-battery warning.
• Step 2: plan to charge somewhere around 20–30% remaining instead of pushing to auto shutdown.
• Step 3: if the pack did run flat and the camera cut out, recharge the same day. Do not leave it empty.
• Step 4: do not leave it parked at 100% on the charger either. Unplug once it is full.

For a new pack, see how to charge an NP-FZ100 the first time.

Habit 2: keep it away from heat

Heat drives lithium degradation, often more than cycle count does.

• Step 1: never leave packs in a sunlit car, on a windowsill or next to a radiator.
• Step 2: charge on a ventilated surface. Do not drape clothing or paper over the charger and pack.
• Step 3: warmth after long recording is normal. Let a pack cool before sealing it into a tight case.
• Step 4: on summer location work, keep spares in shaded packaging rather than exposed to sun.

Habit 3: store at half charge when it sits

This is the one people skip, and it costs them. Both long-term full and long-term empty storage accelerate aging.

• Step 1: bring the pack into roughly 40–60%. No need to hit an exact figure.
• Step 2: store cool and dry, around 15–25°C, away from damp and sharp temperature swings.
• Step 3: set a calendar reminder and top up every three months, returning to the half-charge state.
• Step 4: before reuse, check for bulging and contact oxidation. Full process in long-term camera battery storage.

Habit 4: matched charging gear, unplug when full

Charger logic and pack protection are two separate lines of defense. Mixing in a charger of unknown spec weakens that redundancy.

• Step 1: confirm the charger lists NP-FZ100 compatibility, with tight connectors and pins.
• Step 2: slight warmth while charging is normal. Hot or smelling means cut power and stop using it.
• Step 3: pull the pack once the indicator turns green. Overnight unattended charging is not something we recommend.
• Step 4: clean pack contacts and charger springs periodically. Oxidation causes poor contact and heat.

Swelling and charging heat are worth reading up on separately.

Habit 5: number your packs and rotate them

Without a system, one pack gets deep-cycled every weekend while another sits untouched for months.

• Step 1: label each pack with a number and its purchase date.
• Step 2: rotate by number so cycles spread evenly.
• Step 3: twice a year, do a rough check — under similar conditions, which one empties first?
• Step 4: demote the weakest to backup or retire it. Around two years is a common replacement point; see NP-FZ100 lifespan and capacity loss.
• Step 5: when flying, spares go in carry-on only, never checked, with terminals protected.

One popular tip worth correcting

Some widely shared “life extension” tricks do little. Running a full charge and discharge cycle on a schedule is one of them. Its real effect is helping the body calibrate the display; it does not meaningfully help the cell, and each deep discharge uses up a cycle. What does move the needle is storage charge level, ambient temperature and depth of discharge. Put your attention there instead of collecting tricks — calibration steps are in first charge and calibration.

By the same logic, there is no need to insist on 100% every time. The protection circuit cuts off at the upper limit, so leaving a pack on the charger after the light turns green adds nothing except more hours spent at full charge, which is the state that wears cells fastest. A pack charged to around 80% before a local shoot, then topped up fully before travel, is a reasonable compromise if you want to fuss over it.

FAQ

Does charging to 100% every time hurt the pack?

Occasional full charges are fine. The thing to avoid is sitting at 100% while connected to mains for long periods. Charge before a shoot, unplug when it is done.

How often should I replace a battery?

Capacity is commonly near 80% after 300–500 cycles. Depending on how often you shoot, around two years is a typical replacement point.

Does fast charging shorten life?

Higher current means more heat. If a pack gets noticeably hot while charging, we suggest moving to a gentler charge rate.

Is a pack usable after a year in storage?

Check the shell and charge behavior first. With no swelling and normal charging it is generally usable, though some capacity loss is likely — run a shooting session before trusting it as a main pack.

Building these habits saves more than buying one extra pack. Start with the YO NP-FZ100 compatible battery (2280mAh / about 16.4Wh, around $17.89) or the two-battery kit at around $36.74; the higher-capacity TNP-FZ100 at 2400mAh / about 17.3Wh suits video and cold work. Studios and rental houses managing many packs should use the wholesale inquiry page — one batch makes numbering and rotation far easier.

In one line: a chipped pack talks to the body; a non-chipped one only supplies power. The percentage on your screen is not measured directly. It is estimated by the battery or the camera from voltage, current and elapsed time. A chipped NP-FZ100 passes that information along, so bars and percentages track reality more closely. Without a chip, the body falls back on a rough voltage estimate, which is where display drift comes from.

How the charge display is actually worked out

A lithium discharge curve is very flat through the middle, so voltage and remaining capacity do not map neatly. Estimation generally takes one of two routes:

• Voltage method: read terminal voltage against the discharge curve to infer remaining capacity. Cheap to implement, but it moves with load — during a burst the voltage sags and the indicator can drop sharply, then recover once you stop.
• Coulomb counting: integrate current in and out over time. More accurate, and the usual approach on packs with communication.

The number on screen is often a blend of both, plus temperature compensation and learned history. That explains two familiar behaviors: why the indicator jumps around, and why a fresh pack seems to calibrate over the first few cycles. It also explains why a pack reading 15% in the cold appears to recover after warming in a pocket — the estimate tracks conditions, not only stored energy.

Which route a pack uses has practical consequences. Voltage-based estimation reacts to load, so a burst sequence can drop bars before much energy has actually been drawn. Coulomb counting copes better with that, but drifts over time and benefits from an occasional full cycle to reset. Most bodies blend the two for exactly that reason.

Chipped versus non-chipped

Aspect	With communication chip	Without communication chip
Body charge display	Percentage or reasonably accurate bars	Voltage-based estimate, prone to jumping
Low-battery warning	Timing is generally sensible	May warn early, or fall to zero suddenly
Body recognition	Usually recognized, communication completes	Compatibility messages possible; some functions limited
Safety protection	Handled by the protection circuit, a separate layer	Also handled by the protection circuit — not unprotected
Cost	Slightly higher	Slightly lower

One misconception worth clearing up: the chip handles communication, not safety. Over-charge, over-discharge, over-current and short-circuit protection live in the protection circuit on a different part of the board. A chip does not make a pack safer, and no chip does not mean no protection. For the safety side, see third-party battery safety and swelling.

About the Sony compatibility message

Some Sony bodies show a notice that remaining charge may not be displayed accurately when a compatible pack is fitted. This is common and you can keep shooting — the body simply cannot fully verify the battery’s data. A “cannot recognize” or “cannot use” message is different and worth working through, usually in this order:

• Power down, take the pack out, wipe the contacts with a dry soft cloth, and reseat it.
• Confirm you have an NP-FZ100 and not an NP-FW50, which serves the A6400, A6500 and A7 II series. See the Sony mirrorless battery cross-reference.
• Cross-check with another pack or another body to see whether the fault follows the battery or the camera.

Buying and usage notes

• Prefer a spec that states communication support: a usable display makes it easier to plan a shooting day.
• Do not call a pack faulty over a jumping display: check first whether it happened during burst shooting, recording or cold weather, where estimation drift is normal.
• Give the body a little calibration time: after a few full cycles the display usually tracks better.
• Weight capacity and energy figures more heavily: a stated 2280mAh / 7.2V / about 16.4Wh tells you more than the single word “chipped”. Checks are in how to spot inflated capacity claims.
• Expect a low reading in cold conditions: capacity drops noticeably below freezing and recovers once warmed. It recovers once the pack warms back up.

FAQ

Will a non-chipped pack work in an A7 IV?

It generally powers the camera, though the charge display may be inaccurate and a compatibility message may appear. Whether that is acceptable depends on how you shoot.

Does a chipped battery need activating?

No special procedure. After a few normal charge and discharge cycles the body’s estimate improves. That is calibration, not activation.

It shut down at 30%. Is the battery bad?

It may be an estimation error, or rising internal resistance as the pack ages. If it happens often, check how many cycles the pack has seen.

Does the chip store data about the battery?

The communication chip mainly exchanges charge and status information; exact capability depends on the design. Go by the function description on the product page.

Do I need a chipped pack if I only shoot stills?

Not strictly, and plenty of shooters run non-chipped packs without trouble. The trade-off is planning: with a percentage readout you know when to swap, while a drifting bar display means you swap on a guess or after a warning. If you shoot paid work with no gap for a surprise shutdown, the chipped spec is the easier choice.

If a usable charge display matters to you, choose a spec that states communication support. The YO NP-FZ100 compatible battery (2280mAh / 7.2V / about 16.4Wh, around $17.89) is built to the NP-FZ100 standard, and the two-battery kit at around $36.74 makes rotation and comparison easy. The higher-capacity TNP-FZ100 at 2400mAh / about 17.3Wh sits in the same family. Studios and rental houses ordering 100 units or more should use the wholesale inquiry page to keep model and batch consistent.

“Where is cheapest” is the wrong question on its own. After-sales certainty, the cost of getting the model wrong, and your time count too. Ordering the wrong model, discovering a recognition problem on arrival, or having nobody to contact when something fails all cost more than a few dollars of difference. Below is a side-by-side of four common channels, so you can match one to your quantity and use case.

Four channels compared

Channel	Price profile	Strengths	Watch out for
Camera brand service center / official store	High — a genuine Sony NP-FZ100 usually runs $70 and up	Model certainty, complete service network	Heavy on budget; multi-pack setups get expensive fast
Brand-direct compatible seller (such as YO here)	Clear pricing: NP-FZ100 single around $17.89, two-battery kit around $36.74	Stated specs, published model list, findable support channel	You must confirm your body is on the compatibility list
Local camera store	Varies widely; room to negotiate	Test the fit on the spot, confirm compatibility immediately	Inconsistent batches and stock age; support depends on the shop staying open
Wholesale inquiry	Quoted by volume at 100 units or more, not publicly listed	Suits studios, rental houses and resellers; one consistent batch	Confirm the model list and defective-unit handling up front

Why the same model varies so much in price

Three variables drive the spread:

• Cell grade and batch: the main source of cost difference, and it shows up in cycle life and whether the rated capacity holds.
• Whether support cost is included: products with a stated warranty and return route price that service in.
• Channel depth: every step between factory and buyer adds cost, and lengthens the chain of responsibility when something goes wrong.

Our NP-FZ100 price breakdown goes deeper on cost structure. One caution: a price far below what reasonable cells cost usually means a compromise on cell grade or protection.

Three typical situations

One or two packs for personal use

Prioritize clear specs and findable support. A plainly priced single at around $17.89 or a two-battery kit at around $36.74 beats hours of comparison shopping. Confirm your body is listed: NP-FZ100 covers the A7 III, A7R III/IV/V, A7 IV, A7S III, A9 series, A1, A6600, A6700, A7C series, FX3, FX30 and ZV-E1. The A6400, A6500 and A7 II series use NP-FW50, and the RX100 series uses NP-BX1. Model details are in the Sony mirrorless battery cross-reference.

Two or three packs, and you need a charger

Kits usually beat buying separately. The NP-FZ100 two-battery kit is around $36.74 and the TNP-FZ100 version around $39.92 — comparison in kit versus single. How many you need depends on how long your shooting day runs.

Studios, rental houses and resellers

For 100 units or more, go straight to the wholesale inquiry page. Volume buys more than unit price — it buys one consistent batch, so capacity and internal resistance match across the order, which makes numbering and rotation manageable and lets you settle defective-unit handling at quote stage. With large orders we suggest a small trial run first to confirm compatibility and wear before scaling; the capacity measurement methods described on this site apply here.

Four checks before you order

• Model: confirm which battery your body takes. Do not order on looks alone.
• Specs: do capacity, voltage and energy agree — for example 2280mAh / 7.2V / about 16.4Wh?
• Support: warranty length, return conditions and who is responsible. Detail in warranty and returns.
• Shipping and stock age: cells age on the shelf, so ask for a recent production date.

Hidden costs people forget when comparing

Beyond the sticker: the wrong model means a return cycle, uncertain compatibility means trial and error on set, and no support means you absorb the loss. On paid work these usually outweigh the difference in battery price, which is why we suggest favoring channels with a clear model list and a findable support route. Model details are in the Sony mirrorless battery cross-reference.

SKUs within one channel also differ in value. Here, the single is around $17.89, one battery with charger around $22.93, and two batteries with charger around $36.74, with a standalone charger adding roughly $5. Combining to fit your needs beats defaulting to a kit — the arithmetic is in kit versus single.

FAQ

Online or in-store?

Depends on the situation. In-store lets you test the fit, which helps when you are unsure of the model. Online gives fuller specs and written return terms, and suits comparison and bulk buying.

Does a low price mean a bad product?

Not necessarily, but we suggest weighting self-consistent specs, a support route and batch information over the price tag.

How much do I save buying several?

There is usually a gradient, and the size varies by channel. Buying two or three at once commonly costs less per unit than three separate orders, largely because packaging and shipping are shared. For 100 units or more, check through the wholesale inquiry page.

Is a used battery worth it?

Lithium cells have a finite cycle count and you cannot easily tell how many are left. We suggest caution, and skipping any pack with visible dents or bulges.

For transparent pricing, a published model list and reachable support, look at the YO NP-FZ100 compatible battery (2280mAh / about 16.4Wh; around $17.89 for a single, around $36.74 for the two-battery kit). The higher-capacity TNP-FZ100 at 2400mAh / about 17.3Wh is available too. Studios, rental houses and resellers ordering 100 units or more should use the wholesale inquiry page for volume pricing and a single batch.

Spotting an inflated rating takes a method you can measure, not a feel for the plastic. An NP-FZ100 is rated 2280mAh / 7.2V, which is about 16.4Wh; the 2400mAh version of the same size is about 17.3Wh. Any measurement moves with temperature, discharge current and cutoff voltage, so results land in a band. A figure in the 2200–2260mAh range would be broadly consistent with the label. There is no value in chasing a number down to the last mAh, and no single measurement should be treated as a verdict on its own.

Start by checking the specs against each other

Two quick checks before any hardware comes out:

• Energy conversion: capacity in Ah times voltage in V gives Wh. 2280mAh is 2.28Ah; at 7.2V that is about 16.4Wh. A listing that quotes a large mAh figure with no Wh, or where the two do not match, deserves caution.
• Model and spec: NP-FZ100 is a 7.2V nominal pack covering the A7 IV, A7R V, A7S III, A9 III, A1, A6600, A6700, A7C series, FX3, FX30 and ZV-E1. The A6400, A6500 and A7 II series take NP-FW50 — if the model is wrong, capacity is beside the point. See the Sony mirrorless battery cross-reference.
• Weight as a hint: packs of the same spec tend to cluster in a similar weight range, and a noticeably light one often means less cell capacity. Useful as a secondary clue, not as proof.

Method 1: constant-current discharge (the more accurate route)

This is what hobbyists and repair shops use. You need an electronic load or a discharger with a constant-current mode.

• Charge the pack fully, then let it rest so the voltage settles.
• Set a constant discharge current, roughly 0.2C to 0.5C — somewhere between a few hundred milliamps and just over 1A — and note the start time.
• Stop at the cutoff voltage given by the cell specification, and record total elapsed time.
• Capacity is approximately discharge current times discharge time. At about 1A, a pack that runs a little over two hours is broadly in line with 2280mAh.

Two caveats: higher discharge current usually yields lower measured capacity, and cold conditions push results down. It is more sensible to compare two packs side by side under identical conditions than to fixate on an absolute number.

Method 2: measuring charge input (no special gear)

Without a load, you can estimate indirectly using a charger or USB meter that logs energy.

• Run the pack down to the camera’s low-battery warning — no need to force a shutdown.
• Charge it fully through a metering device and read the accumulated mAh or Wh.
• Allow for charge efficiency and for the charge that was left at the start; the result usually reads a little above what the pack actually delivered. Treat it as an order-of-magnitude check: well under half the rating is a red flag; close to it is reassuring.

Method 3: frames per charge (closest to real use)

For most shooters, what matters is how much you get through in a session.

• Charge one pack and shoot continuously under fixed settings — same body, same mode, similar temperature — noting the frame count at the low-battery warning.
• Official CIPA figures usually sit between 500 and 700 frames, with real-world results commonly 60–80% of that, lower for video and burst work.
• Compare against another pack you know is healthy. A difference inside a reasonable band is fine; if it is clearly short, confirm with method 1.

If capacity genuinely looks far off the label, talk to support; the process is outlined in warranty and returns. Note also that capacity is commonly around 80% after 300–500 cycles, so a low reading on an older pack may just be wear.

Cases that look like inflation but are not

• Cold: capacity drops noticeably below freezing and may be roughly halved near -10°C. Warm the pack to room temperature before measuring. See cold-weather runtime tips.
• High current draw: burst shooting and 4K recording reduce usable capacity below the rating.
• Charge display jumping: that is estimation and communication behavior, not directly a capacity shortfall. It comes from estimation and communication behavior rather than stored energy.
• An old pack: on a battery past two years, wear can exceed any inflation gap.

FAQ

Does measuring below the rating mean the rating is fake?

Not on its own. Temperature, discharge current and cutoff setting all move the result. Compare like with like and accept a band of error.

How many more frames does 2400mAh give over 2280mAh?

About 5% more energy in theory. In practice the difference depends on body and settings, rarely scales linearly, and is modest in daily use.

Can I test with a phone charger?

We do not recommend working directly on battery terminals. Charge camera batteries in a proper charger, and keep any measurement within safe practice.

What if my result is clearly low?

Rule out temperature and age first, keep your measurement notes, then contact support. Do not keep using a pack that runs unusually hot or has started to swell.

Choosing a product that states its specs clearly saves you the testing. The YO NP-FZ100 compatible battery is listed at 2280mAh / 7.2V / about 16.4Wh, and the TNP-FZ100 at 2400mAh / about 17.3Wh; the two-battery kit at around $36.74 also makes side-by-side comparison easy. Studios and resellers ordering 100 units or more should use the wholesale inquiry page — a small trial order first, then scale up.