How do you store your batteries?

I know your not supposed to, but I typically store mine charged in plastic cases designed for that size cell. If I had a charger that would do a storage charge, I would use that. I have a few cells, 18500s and 16340s, that I have nothing to use in right now.

I “store” mine at 75%. Low enough to improve the lifespan of the cell while still allowing for a decent usable capacity if I need it right away. Room temp, which can hit 80F where I live.

What is that?

What happens when you keep a lithium-ion battery fully-charged all the time:

This was not an isolated incident. The entire test lab had similar problems, multiple phone models from multiple manufacturers, because they were constantly plugged in and the charge kept oscillating between ~95% and 100% as the devices went through automatic top-off cycles. The pattern at the right of this graph was basically repeated nonstop whenever the devices were plugged in, which was all the time in a test lab environment:

The inflated battery shown earlier is what would happen pretty consistently after about 6 to 18 months of being plugged in, even if it was idle most of the time. At about 18 months, no devices were functional any more. However, an extra which was stored half-full with the power off … was still nearly as good as new.

Cylindrical cells don’t tend to balloon like that, due to the outer shell being strong, but they still lose capacity and build up pressure.

Keeping li-ion cells full in storage, and topping them off frequently, is one of the most effective ways to kill them faster.

:+1: thanks :slight_smile:

Same here…I don’t have any extra LiIon cells. When I’m going hiking, boating, camping, whatever for a while, regular light gets a top up so it’s good to go for the “event”, and it gets used a fair bit. I have 2 x 18650 cells for flashlights and one is always in the truck, and one is at home by the bed - both get used regularly and I swap the batteries around when charging as the one in the truck is used a bit more frequently. This helps to keep the cells at similar capacities. If one fails, I’d just order another protected 18650 cell.

For NiMH which can be stored fully charged, I have a lots of spares and I rotate them through remotes, clocks, small flashlights for backup and around the house activities, etc. These I top up and store in a room temperature drawer till they get swapped out, which is fairly often for remotes. I make sure to rotate them when charging too.

I didn’t vote in the poll as there is no option for “I don’t store them, I use them”. :smiley:

I had two nimh packs which I left charged (without using) for a year or two, they died completely.
Won’t hold any capacity, and produce very little voltage.
:frowning: rip

Should have cycled them every few months I guess.

And yeah you’re right, if you just use batteries without storing then the poll doesn’t really apply to you :stuck_out_tongue:

+ 1 in my opinion. Being through the east eye wall of Katrina. I’ve gotten to wear I horde batteries now. All the pulls I can find. Usually anything 1200+ Ill keep and fully charged. Just for hurricane preparedness. Like you said if there’s warning I’ll top them all off for whatever self discjarge occoured. Used and free not really concerned if they loose some life at full charge.

Edit, my good cells I use in my flashlights get rotated about every 4-6 weeks. I’ll put them in a powerbank and use them. But all the extra free pulls over the last 6 months of recycle bin pulling stay fully charged. But my opus only charged to 4.13 so I guess its not really maxed topped off. Usually settle to around 4.1

Fully charged, boxed and in the fridge.

I stopped using protected cells because there’s always a small parasitic drain from the protection circuit. The only cells I had actually croke dead from disuse were protected. I still have the 2 original protected panny-Bs, but I keep them in my regular-use lights (EDC and headlamp).

The other lights are more or less special-purpose, but still somewhat regular use. C8 for yard-snooping, VG10 for non-EDC general-purpose use, etc. The other unprotected panny-Bs and 30Qs, and some powerbank pulls, I keep shelved at less-than-topped-up levels.

Only in case of a big storm coming, high winds, etc., will I grab all the in-light cells and top them off. Worst case, I can always top up cells when needed from inside the car.

Old NiMH batteries tend to die anyway. They basically had to be re-conditioned on a regular and frequent schedule.

Newer “LSD” NiMH is much better at remaining useful for years and years, and doesn’t require much maintenance or special care. It’s still a good idea to fully charge and fully discharge them though.

Li-ion is different than either of the above, since it doesn’t like being fully charged and really doesn’t like being fully discharged. It’s happiest right in the middle.

LSD like the drug? :stuck_out_tongue:
I mean I didn’t expect them to die so fast, some of my other nimh RC battery packs were perfectly fine sitting fully charged for long periods of time.
They must have been lower quality cells or something.

I use eneloops, so I voted for fully charged. The poll did not specify what chemistry . . .

I have some experience with 10 year old nimh non eneloops I came across recently. Roughly 50% were toast, the other 50% I was able to charge and discharge a few times and now they deliver near capacity. I don’t have a accurate way of measuring the capacity, but they last for 5 hours at 75 lumens in my TN Archer 1AV3. This is how long Thrunite claims they will run at 75 lumens, but does not specify a battery type. So these old cells can still be usedful. Mine were a mixture of Energizer 2500s and duracell 2650s. I will say the duracells had a much higher recovery rate than the energizers. Like 7-8 duracells and 2-8 energizers. I think the energizers had seen a few quick (15 min) charge cycles in their life though.

HPAC: High Precision Air Conditioning.
Designed specially to cool temperature heating from equipment. On the other site are comfort air conditioner designed for home application.

I keep them at 100%, battery are cheap enough to not worry about replacing them, But in an emergency every % point may count.

Any of my device with built in li-ion battery`s phone/tablet are charged to 80% and never drop below 20% apart from an 12 month recalibration charge.

John.

I keep hundreds of 18650 laptop pulls in original condition, some still in battery packs; and
old RC li-pos and assorted other potentially toxic or energy dense dangers, in tin boxes in a shed away from the house.

Lots of fully charged Li-ions are kept in torches all over the place, and a bunch of depleted cells waiting to be charged are kept piled in plastic boxes on a desk.

No special voltage for storage, some fully charged, some fully depleted. Have a couple of hundred lithium ion batteries and in 8 years or so have only had 2 or 3 batteries go bad, this is including 8 year old batteries. Storage voltage level is overrated.

I agree on this, I keep extra batteries for emergencies. Whenever I would need it I know its fully charged. That’s the reason I bought a lot of 18650 for power outage in an inevitable time.

I try to keep mine stored at 3.6V to 3.7V. Of course the few I use, I fully charge. I recently found a Panasonic 18650B in a light that used to have 3300mAh when I first got it. It now only has a capacity of around 2800mAh. It was sitting fully charged for about 2 years. BTW, as a fully charged cell self discharges, the stress on the cell is relieved somewhat as the voltage declines. Even though, it harms the cell. Imagine how much more harm is done when cells are left constantly charging in laptops that are plugged in. Those cells see tremendous stress as they are constantly topped off and receive more stress with no relief.
Then think of the even more stress that GPS units receive stuck to the windshield of a car in the hot sun. In fact that combined with the black case many of them have, leads to an early death. The only GPS units I have that still have working cells are the ones with white cases.
I was greatly encouraged when I opened up a brand new, unused GPS receiver that I had purchased in 2006. Before I turned it on I opened it up and checked the voltage on the included Li-ion cell. Even though it was 10 years old, it was sitting at around 3.5V. I charged it up and did a capacity check with my OPUS. I don’t remember the exact number but it tested out to around 95% of capacity. Also the GPS had a run time of about 3 hours, it’s stated runtime, and that too confirmed that Li-ion cells do very well stored at half capacity, even the ones manufactured 10 years ago. I can only assume they are even better now.

I don’t really “store” cells… even though i have a small metal suit case with between one and half dozen spare of each size - probably more 18650 though, in appropriate plastic cases. Those are ‘new’ or not yet used except for a few i happen to use in a rotation - but i usually don’t put them in this ‘bin’; i tend to keep them close to the device they are used in.

The big chunk of my cells are ‘stored’ in flashlights (totally lost count since i joined BLF), hopefully fully charged. Most i don’t use much, and when i happen to use one, i usually top off the cell right away before putting the light back in it’s place.

I understand that Li-ion batteries will last longer if treated just right… but i’d rather have cells ready to use that will decline faster then cells i can’t use right away if i need them, but that will last longer. During the past four years i’ve used them, li-ion cells have evolved faster then their obsolescence rate so that you probably want to renew them for increased capacity and/or amps.