I have a "bunch" now and more coming. Problem is that for long term storage, they need to be stored at a lower voltage. I don't have a good way to lower the voltage. All my chargers are just chargers. None of them are made to discharge. From all I read, the cells should be stored at between 30-50% charge.
I have been storing them fully charged, but apparently, that is not the correct method. Since I only really use them for testing lights, they see long storage times, with little use.
I got some of those lime green cells from a laptop pull once - loved the color, but they were in bad shape. Only tested to 800mAh with high resistance…
Out of curiosity, what is your charging schedule? I usually keep about 10x18650’s charged and ready to go, and charge all regularly used cells once a week on the weekend.
OldLumens - I store mine in the 3.6-3.8V range. I use either a usb power bank to discharge them on the Lii-300 analyzer (which I have up for sale ), then top off a bit to get them in this range. Stacked neatly in a couple of very well fitting small boxes. They do lose more capacity over time when stored full.
Fun part is remembering what has and hasn’t been charged. What light has what cell in it and did I lock it out? I have woken up and gone check a light. Bit anal, but hey that is the fun in the hobby.
OL is right. Unless you plan on using these cells within a couple of months they should NOT be stored fully charged. Nor should they be stored fully discharged.
This is no time to be OCD about keeping ALL of your cells charged up.
BTW, there is a switch inside the OPUS that can be set to charge up to 3.7v, an ideal storage charge.
The 'storage charge' setting would be a good suggestion to Xtar for the next iteration of their chargers. And if that setting charges to 3.6 volts, it facilitates the LiFePo-lovers without having to say that and thus avoid liability for misuse. Design weirdness like hiding the LiFePo inside on the circuit board is not neccessary that way.
I have a two bay charger and it takes forever to charge.
I have around a dozen of Sanyo 2600 laptop pulls. I charge in two steps. First round it to bring them up to 4.0V. Second round is to charge them up to 4.2V.
You would think a dozen batteries is a lot, but I can discharge them back down to 3.7V in just a couple days of normal use.
If I am awake and around my charger is busy charging. I don’t dare charge unattended or when I’m sleep. Even Eneloops.
Say it isn’t so. Use a flashlight to discharge batteries? I’ll have to try that :bigsmile:
So far, I typically rotate mine through a 3 step process. I use mine until they start to dim, then I charge them until about 3.6-3.8v and put them in the fridge. Then I take some out of the fridge and charge them to full. Then I take my already full stockpile and put them in my lights. I’m fairly new to all of this, and would have normally just charged them all and stored them, but this website is a wealth of knowledge. The only reason I charged up all of them today is I plan on doing some modding and light testing over the next week or two and I know I’m going to go through some batteries. When I’m done, I’ll just go back to my rotation.
I store my batteries fully charged. Even if I assume that it will shorten their lives in half, they’ll still last for years with my rate of usage. So why bother?
If you don't go through a lot of batteries, why bother keeping them all charged? Li-ion that is...
If disaster strike, it should be easy to charge all your li-ion batteries using a charger that can run from a car battery, if needed.
I also do as some already have suggested: I try to rotate as few li-ion as possible. Just the ones that already are in use. If I buy a new torch I often pension another. I try to put all the wear on as few batteries as possible. I store spares cool and dry at 3.7V until needed, when I notice (Charge Test on my Opus 3100) that the capacity of the batteries in use start to drop. And you are this way likely to have more and better batteries as spares. If I notice that I don't have a lot of unused spares, I send for more. No hurry, 3-4 months surface mail delivery is fine...
LSD Ni-MH (Eneloop/Ready-To-Use/LADDA/...) should be treated in the opposite way. Spread the wear on all of them, and try to make sure they all get a discharge/recharge cycle at least every 6 months or so. And store them fully charged. I rotate and "exercise" all my Ni-MH during the holidays in winter.
Normal (high self discharge) Ni-MH should be rotated even more often.
I have just enough batteries for few lights, power bank + few spares. I don’t use them often, but if I go camping I do need most of them. Topping up even 10 batteries with i2 would take couple of days. I just don’t think the profit of extended battery life is worth all the hassle of keeping the batteries half discharged most of the time, not for me at least. Maybe if I had huge pile of spares I would keep them at 50% until I need them to replace worn off batteries.
), then top off a bit to get them in this range. Stacked neatly in a couple of very well fitting small boxes. They do lose more capacity over time when stored full.
