Yep, another newbie question. This has to do with storage.
If I were to buy new batteries and not use them, how do I store them. I have read to keep them cool and dry, keep them at a certain charge, checking them every few months to maintain that charge.
I have also read two different things on storage life. One said they can last up to 10 years, (not sure if that is storage or in use), and another site said 3-5 years even if unused, and another said they will lose 20% capacity each year no matter how they are stored or used.
I don’t want to keep a lot of unused batteries laying around if shelf life is only a few years.
Even if the capacity of the cell decreases by 20% every year (which I don’t think is the case), it wouldn’t be too noticeable so I wouldn’t be too concerned.
It’s good to have a cell for each flashlight just in case, but I haven’t been concerned about shelf life.
It’s recommended to store them at 50% charge, which falls between 3.75-3.80V in order to maximize the shelf life.
There are a number of conflicting reports on how they will degrade over time, although I find much of it is overstated. I have cells dated 7+ years old which have lost less than 25% capacity whilst having been in use for a lot of that time.
The optimal way to store them is somewhere around 30-50% charged (3.6-3.8v) and at cool temperatures, e.g. in the fridge. You don’t want to take them too cold or overdischarge them though.
Most cells will come with a good charge for long term storage so you can just leave them somewhere cool if you don’t plan on using them straight away. The key things to remember are not to leave them anywhere hot, not to leave them fully/over discharged for any time period, and not to leave them fully charged for long time periods.