Month: March 2026

Short answer: a 950mAh LP-E17 that will sit unused should be stored at four to six tenths of charge, at 15-25°C, and topped up every three to six months. Charging it fully before putting it away is the most common mistake: at a full charge the cathode sits at a high potential, side reactions are more active, and a few months of that can cost more capacity than a year of normal use. Storing it completely flat is just as bad, because a deep over-discharge can kill the battery outright.

The 950mAh sits in the middle of the three tiers, neither small nor large, which makes it the easiest to forget: it is not carried as a casual spare like the 750mAh, nor used daily as a primary like the 1050mAh, so it often sits for six months at a time. This tier needs a clear set of storage rules more than the others.

Why four to six tenths and not full

A lithium-ion battery is most stable at a moderate state of charge. At a high charge the cathode material is strongly oxidizing, side reactions with the electrolyte run faster and the SEI layer thickens sooner. At a low charge the anode potential rises, the copper current collector is at risk of dissolving, and an over-discharged battery may never charge again.

Four to six tenths is the balance point between those two risks. You do not need to be precise: two bars on the camera gauge, where full is three or four, lands roughly in that range, or you can pull the battery off the dock partway through a charge. Approximate is fine.

Temperature matters as much as charge level. Side reactions accelerate noticeably in the heat, so keep batteries away from balconies, radiators, cars and anything that runs warm. Dry, dark and 15-25°C is ideal.

How often to top up

Self-discharge in a lithium-ion battery typically runs at 2-5% a month, and the protection board’s quiescent draw adds a little more. At that rate, going from five tenths down to below two tenths takes roughly three to six months, which is where the top-up interval comes from.

A top-up does not mean a full charge. Take the battery off at around halfway and put it back into storage; charging it fully every time recreates the harmful full-charge state. If your dock has no way to stop partway, timing it with a watch gives a close enough estimate.

A storage routine you can follow as written

1. Clean the contacts. Wipe the metal contacts on the battery and in the body with a dry soft cloth to remove fingerprints and oxidation. Do not use much alcohol and do not scrape.
2. Set the charge level. Bring the battery to four to six tenths. If it is already full, fit it in the body and run it down for a while, or shoot a few dozen frames.
3. Take it out of the body. Do not leave it in the camera long term. Even switched off, a body draws a little, which can drag a battery into over-discharge, and the battery compartment is also where moisture collects.
4. Store it separately. Use the original box or a battery case with dividers, and keep it away from keys, coins and metal fittings to prevent a short across the contacts.
5. Choose the place. Cool, dry and dark, away from heat. A small sachet of desiccant in the case helps, especially in a humid season.
6. Set a reminder. Put a date three months out in the calendar to check the charge and restore it to five tenths. This step is the easiest to skip and the one that decides the outcome.

If you store several batteries, label each one with the date it went in and its charge at the time, so the next retrieval needs no guesswork. That habit pays off most for anyone mixing capacities.

Three common mistakes

Mistake one: the fridge will extend life. Not advisable. A domestic fridge is humid, condensation forms on the battery as you take it out, and moisture working into the case seams adds risk. Repeated temperature swings also increase internal stress. A cool spot at room temperature is enough.

Mistake two: charge it full so it is ready next time. Convenient, but it accelerates aging. If you really need a battery that is ready at any moment, keep one emergency battery full and store the rest at five tenths, accepting that the emergency battery will have a shorter life.

Mistake three: leaving the battery in the camera counts as storing it. A camera is not a storage box. Removing the battery when the camera is not in use is basic practice, as the LP-E17 overview also notes. Fit the battery compartment cover afterwards to keep dust out.

One more point: if a battery swells, smells odd or becomes unusually hot during storage, do not charge it and do not keep it. Dispose of it under your local electronic waste rules. This is uncommon, but there is no recovery once it happens.

When you bring a battery back into use after several months, check first that the case is flat, then charge it on the dock and watch whether the process behaves normally. On the first use after a full charge the runtime may come in slightly below what you remember; that is usually a normal dormant state, and two or three full cycles bring it back close to where it was.

If it is still clearly short after two or three cycles, that is genuine degradation. Use the method for judging capacity fade as a reference, or check the capacity and compatibility guide to decide whether a replacement is due. For this tier, allow some margin on the first two shoots after a long rest and avoid scheduling anything that cannot be interrupted.

FAQ

How often does a stored 950mAh need a top-up?

Usually every three to six months, depending on storage temperature. Warmer storage means faster self-discharge, so in summer shorten it to three months; in a stable cool place four months is fine. Top up to five tenths, not to full.

Can long storage ruin a battery?

It can, but it is usually avoidable. The real risks are the two extremes: sitting fully charged for months, or sitting fully discharged for months. Kept at four to six tenths and checked regularly, most batteries lose very little capacity over a year. Left completely flat and never recharged, a battery may never come back.

Can I store batteries in the camera bag?

Yes, with two conditions: the batteries come out of the body, and each one goes in its own case or pouch. A camera bag is not sealed, so add desiccant in the humid season and avoid leaving the bag on the floor or against an outside wall.

Should I drain a battery before storing it?

No, that is a habit from the nickel-cadmium era. Lithium-ion batteries have no memory effect, and draining one only adds over-discharge risk. The goal before storage is a middle charge, not zero.

Short answer: recording 4K on the EOS R8, most sessions hit the body’s thermal limit before the battery runs down. The job of a 1050mAh is to raise how much you can record in total, not to stretch any single clip indefinitely. As a rough estimate, at room temperature in the low twenties with the screen on and intermittent recording, a fully charged 1050mAh supports around sixty minutes of accumulated 4K footage, and where it lands in that range depends on resolution and frame rate, bit rate, and cooling; with one continuous clip, the heat warning usually arrives first.

Where the R8’s 4K heat comes from, and what the battery contributes

4K power draw goes mainly to three places: high-resolution readout from the sensor, encoding in the image processor, and card writes. The R8 body is compact with limited surface area, so heat accumulates in the space between the sensor and the main board and bleeds out slowly through the shell. That is why it barely warms up when shooting stills and becomes obvious the moment you switch to 4K.

The battery also produces heat, but on a much smaller scale. One quiet advantage of a 1050mAh over a 950mAh is that at the same output power the cell discharges at a lower rate, so less is lost to internal resistance and converted into heat. That will not cool the body, but it keeps the rise around the battery compartment slightly lower, which helps on long recordings.

Worth noting: a warmer battery has higher internal resistance, and higher resistance brings more voltage sag and more heat, a small feedback loop. So when a battery feels hot to the touch after continuous outdoor shooting in summer, its usable capacity is effectively discounted. That is a separate issue from body overheating, but the two happen at the same time.

Realistic runtime ranges in three scenarios

Treating “recording 4K” as a single activity leads to bad estimates. The table below splits it into three common patterns. The figures are ranges that move with bit rate, temperature, screen brightness, and stabilization, and are for planning only, not a promise.

Why might one long clip use less power? Because every start and stop sends the sensor and processor through another warm-up and initialization, and the transient draw exceeds the steady state. Intermittent recording, on the other hand, keeps the body cooler so the thermal limit arrives later. The two pull against each other; the right choice depends on whether you need one complete long take or a steady stream of material all day.

Heat first or empty first: three variables decide

Ambient temperature is the first. Recording 4K outdoors in winter, the thermal limit will basically never appear and you will genuinely use the pack up; on a summer afternoon the body may throw a temperature warning while you still have half a charge. This is why many people find batteries “long-lasting” in winter and “useless” in summer. It is the same battery.

Second is resolution and frame rate. 4K 50/60p puts clearly more readout and encoding load on the system than 25p, raising heat and draw together. If the deliverable only needs 25p, there is no reason to run high frame rates all day.

Third is the screen and ports. A screen held at high brightness, Wi-Fi transfer left on, and an external monitor all add several watts. Against a battery in the seven-and-a-half watt-hour class, those small loads are a meaningful share.

A sequence for getting the most out of a 1050mAh

1. Charge fully before you leave and confirm the pack is at room temperature. Do not take a battery straight out of an air-conditioned room and put it into a body that has been sitting in the sun.
2. Set the body to its standard power-saving profile, drop screen brightness one notch manually, and turn off wireless features you do not need.
3. Open with 4K 25p for the main shots and save high frame rates for the takes that genuinely need them, cutting unnecessary encoding load.
4. Every ten to fifteen minutes of recording, let the body idle for a minute or two to shed heat. Do not blast the lens mount with a fan; a sudden chill causes condensation inside.
5. Start planning the finish when the gauge reaches two bars, not at auto-shutdown. Lithium-ion voltage falls quickly at the tail, and a sudden cut can leave the last clip incompletely written.

If a day involves a lot of 4K, the practical approach is two 1050mAh packs in rotation rather than expecting one to last. Let a freshly pulled pack cool in the open air before it goes on a charger. In this role the YO LP-E17 1050mAh is the standard primary pack, with the 950mAh tier as a sensible backup.

One more point that is often missed: a battery with a USB-C port solves off-camera replenishment, not on-camera power. Whether you can charge and record at the same time depends on whether the body supports a USB power-delivery protocol, and such modes usually restrict recording specifications. Check the body manual rather than assuming that plugging in means unlimited recording.

FAQ

Can a 1050mAh record a full hour of 4K on the R8?

With intermittent recording at normal temperature and 25p, it can approach that. Continuous single clips, high frame rates, or hot conditions usually fall short. Treat an hour as an upper reference and plan on about seventy percent of it.

After a heat warning, can I swap batteries and keep recording?

That does not address the cause. The thermal limit comes from the body’s internal temperature, and a fresh battery will not cool it; most bodies restrict recording specifications for a period. Switch off and let it cool instead of retrying repeatedly.

Why is charging from a power bank while recording not recommended?

For one thing, charging and recording at once adds heat to a body that is already thermally tight. For another, some bodies restrict 4K specifications in that state. For long sessions, prefer an external power solution or shoot in segments, and check the body manual for what is supported.

How many extra minutes does 1050mAh give over the original 1040mAh?

The difference is on the order of one percent, theoretically under a minute, and in practice it is lost in heat and shooting rhythm. The case for 1050mAh rests on the gap to the 750 and 950 tiers, not on ten milliamp-hours against the original. For more on the tiers, see the 1050mAh category.

Short answer: for an eight- to ten-hour wedding on a full-frame mirrorless body like the EOS R8 or RP, mixing the screen and the viewfinder, four 1050mAh packs is usually the safe number, with one in the body and three in the bag. On a DSLR built around the optical finder, such as the 850D or 77D, three is often enough. The real risk is rarely “not enough capacity.” It is rotation chaos: reaching for a pack at the critical moment and finding it empty, or having two full ones buried at the bottom of the bag.

This is not a general article about saving power. It breaks the budget down along the actual shape of a wedding day and gives a rotation routine you can follow as written.

The day’s power budget, stage by stage

Wedding shooting does not draw power evenly. The preparation stage is heavy on screen review and focusing, the ceremony on continuous tracking and bursts, the banquet on power cycling and playback, and the location shoot may involve long idle periods. Splitting the day into four stages is more useful than asking how many frames one battery takes.

That totals three and a half to four and a half packs, estimated for a mirrorless body using the electronic finder throughout. A DSLR on the optical finder with light review can come in around two and a half. The figures are empirical ranges; body model, temperature, stabilization, and wireless transfer all shift them, so plan to the upper bound rather than the average.

Arranging four packs: a rotation routine you can execute

1. Charge everything and number the packs before you leave. Mark 1, 2, 3, 4 on the back with a paint pen or a sticker, and keep the numbering tied to a fixed slot so you are not identifying packs by feel on site.
2. Use them in numerical order. The body always holds the lowest number; when you pull one, it goes straight into a designated “used” pouch in the bag, never mixed with the charged ones.
3. Swap at safe moments. Choose low-risk windows such as the end of the ceremony, the car between locations, or just before the banquet is served, rather than waiting for the low-battery warning.
4. Top up once mid-day. During the lunchtime move or a banquet lull, put the two used packs on the dock. Many shooters drop their real daily need from five packs to four this way.
5. Split them onto chargers the moment you finish. Get all four on power so that tomorrow does not start at half charge because you forgot.

The point of the routine is not saving power but turning “how much charge do I have left” into a state you can read at a glance. Event lighting is difficult and the pace is fast; anything that requires on-the-spot judgment costs attention.

Three details that go wrong

Spare packs go in a pocket against your body, not the bottom of the bag

Lithium-ion internal resistance rises in the cold and usable capacity falls. On a winter location shoot, an inside jacket pocket will get noticeably more out of a spare than a side pocket of the backpack. The difference is obvious at outdoor weddings in cold regions, and never store a pack against an ice pack either.

Do not stretch one pack across an entire ceremony

The ceremony is the part you cannot redo. Even if the current pack looks sufficient, fit a full one before it starts and save the half-used pack for the banquet. Trading headroom for insurance is the best deal in event work.

Wipe the contacts and the compartment

When you swap often, sweat and dust on the contacts cause poor connection, false charge readings, and even sudden shutdowns. Keep a clean microfiber cloth and wipe the contacts at each swap. That prevents more incidents than carrying an extra battery.

Why events call for 1050mAh rather than 750mAh

The 750mAh version is fine as a backup pack or for short top-ups, but in a setting where you cannot afford an interruption its weakness is not total energy. It is swap frequency. Each tier down costs you one or two extra swaps a day, and every swap is a window of risk. A 1050mAh carries about forty percent more rated capacity than a 750mAh and typically brings five swaps down to around three.

If the budget is tight, mix: two 1050mAh for the critical ceremony and banquet blocks, two 950mAh for preparation and the location shoot. For the differences between tiers, see the specifications in the 1050mAh category and the 950mAh category, then set your own ratio.

YO is conservative about capacity claims: 1050mAh is the rated figure, with no extra marketing padding. For event work that consistency is worth more than an impressive number, because knowing how long the pack in your hand will last is what lets you plan the next step.

FAQ

Are three 1050mAh packs enough for a wedding?

Usually enough on a DSLR using the optical finder with light review; on a full-frame mirrorless body using the electronic finder throughout it is tight, so plan for four and top up at lunch.

Can two packs be charged and used alternately?

Yes, but avoid charging one while shooting with it on site. A dock needs time to fill, and with a tight schedule two packs in rotation can leave you with a gap during a move; three or more is more comfortable.

Does storing a battery full shorten its life?

Yes. Long storage at full charge or fully drained both accelerate capacity loss. If the pack will sit unused after the wedding, discharge it to about half, store it, and top it up every few months.

Is fast drain in cold weather a sign the battery is failing?

Usually not. Cold temporarily raises internal resistance and lowers usable capacity, and it typically recovers at room temperature. Only if runtime is clearly short at normal temperatures should you consider replacing it.