What charge level do you typically store your lithium ion batteries at?

The Opus 3100 V2.2 has a hidden slide switch under the bottom cover that limits charge voltage. It's set to 4.2v from the factory. The other settings are 3.7v and 4.35v. I cut a small hole in the bottom cover so I could easily adjust it to 3.7v for cell storage. The switch is undocumented in the owners manual. I learned about it here in a 3100 thread.

slmjim

Fully charged; topped off monthly. (usually)
I have some computer battery pulls that are over 10 years old and still work fine.

now someone chart how much you can save {money}
vs. amount of time and brain energy expended doing so

I keep my edc light pretty well topped off. Other lights that get less frequent use I prefer to keep in the mid 3V range, but I don’t go out of my way to charge or discharge to that level. If I notice they’re getting down below the mid 3 range I’ll toss them on the charger for a little while but I may or may not pull them before they get completely topped off.

This is pretty much what I do too.

For storage, I am only concern by voltage and don’t care about capacity and % of capacity.

This is a good question, as I know I’m pretty bad about this.

I tend to keep a bunch my lights fully gassed up and ready go, north of 4 v. Darkness might strike at any moment. This means the batteries in lights I use frequently get topped off a lot. I know this is a bad habit, as this is more than twenty lights and some don’t get turned on for weeks, but this is not always about being rational.

I keep a just couple of batteries fully charged outside of lights, just if I need to take a spare 16340 or 18650 with me somewhere. Batteries that I’m storing are south of 3.8 volts.

Storing all spares in the fridge is something I should probably think about. Good idea!

Whenever I get any new cells (discrete or included with lights) I always cap-test them, so they typically go back up to 4.2V, as I don’t stay up all night babysitting them.

I might give ’em a blast on turbo to burn off a fractional-volt or so, but that’s it.

I just bought an EXTAR VC8 + 8 bay charger and it has a storage setting. It will discharge or charge to get to 3.7 volts. I have several chargers but I am kinda digging this one as it does it all. Hope this helps

Not sure if any others already mentioned, but the SkyRC MC3000 specifically allows to do that, even allowing other charging parameters (like the charge current and end-charge/termination current, which also affects the charged voltage a bit). Although the MC3000 is a much more expensive charger.

One can set up to what voltage the battery gets charged to, or when discharging, up to what voltage (in 0.01v increments)
Or when set to “storage” mode, the charger will then charge or discharge up to the user-specified voltage.

Usually around half charge. I only usually fully charge cells if I am going to be using a light for a few hours. Otherwise its a quick charge at my desk.

Are you sure it has a storage setting, I cannot find that anywhere.

yeah you could spend hours doing that and save 23 cents when the light lasts 3.3 weeks longer than otherwise

Lots of interesting replies.
I try to make my batteries last as long as possible since i can’t afford to replace them.
I guess if that was not a concern i could just store everything fully charged. It would certainly be easier/less work to do that.

I try to store batteries around 4V or 80%. Though with my new EDC (Wurkkos FC11) with integrated charging i am just fully charging it then recharging when empty a week or two later and considering it a throwaway battery when its toast.

So you can set this charger to charge to exactly 4.0V for example?

usually you cannot set charger termination voltage

I knew this already :wink:

% is a weird symbol to use for volts.
I only charge mine to 4.2 volts. I don’t recommend any of those other options unless you have a bunch in series.

100% positive , I have been using this function. Its the 8 bay plus model . You must use the first 4 bays and must hold the mode button down until GRAD comes up. Then you push it one more time and STORE lights up . Will do 4 at a time for those 2 functions. All 8 bays will do IR ,CUR, CAP.

With the SkyRC MC3000, set the battery type to “Li-Ion”, set to “Charge” mode, I can set the end-charge voltage to anywhere from 4.00 to 4.25v, in 0.01v increments.

If I had wanted to charge the battery to lower than 4.00v, set to “Storage” mode instead, then I can set the end-charge voltage from 3.65 to 4.00v, in 0.01v increment

If I want to charge to lower than 3.65v, I can set to “LiFe” mode, then the Charge voltage or Storage voltage can be lower voltage.

Setting to “Discharge” mode, set to “Li-Ion” battery type, can discharge the battery to anywhere from 3.65v down to 2.50v, in 0.01v decrement.

So it’s basically fully programmable. But there may be a learning curve to use this charger, depending on how familiar one is with regards to changing settings.

Very nice!
I will have to save up for one.