Do any of y'all keep backup batteries stored at the proper voltage? If so, how many years have they been fine when pulled out and charged up for use?
I have extra-extra batteries I want to keep on standbye and I'm curious what their shelf life might be. They are Keeppower 21700s I plan to test and charge as needed annually.
by a-null-fish-your
4 Comments
I found 4 Varicore 18650 I bought 7 years ago(never used). Worked good, low resistance(<25), capacity as new… But I threw them away, and bought some Tenpower cells from reputable seller in Europe.
I’ve been meaning to test the storage function of my Xtar VX2 Pro to see if it’ll easily drop backup cells to an appropriate level as it claims…
Have some 18650 Panasonic ncm cells from 2012 that are inside a fenix tk75. They seem to take about 85% charge from new.
Now I have a bunch of 21700 lights, a couple are in regular rotation. The rest are at. 60% charge and physically locked out.
I had some 18650 VTC6 stored normally after charging to full, and still above 4V when checked after about 2 years.
If the cell drain by itself in couple months, then it’s faulty…
Just keep in mind I’m talking about unprotected ones.
In your case, you can just store them, and see if voltage isn’t dropping every other month with multimeter…