Since I got mostly laptop pulls I keep em fully charged don’t really care about degradation. I’ve got 2 protected pannies for my headlamp that I use daily so I keep em fully charged. And an unprotected GA for my MH20 that I use with a diffuser as a lantern. When it runs out of juice I replace it with a laptop pull (which are 4.25V charged to 4.10-4.15V).
I’ve got one more laptop pack that I didn’t open yet and 4 unprotected GA for the Q8 at storage voltage. My 14500 I have to recharge everyday if/when I use them.
I don’t really see the point of storage charge for me cause I deplete em all within a month or 2. The protected pannies I charge every few days. But that might change since the days are getting much longer now and I get more power from my solar setup…
How do you guys and girls treat your power tool packs?
I am quite confident in my choice. I ‘store’ at 4.10v. The idea is it packs them with nearly a full charge, but doesn’t stress them. I believe saying lithium can charge to 4.20v is a something manufacturers do to squeeze the best specs out of lithium, and rightfully so… I charge to 4.20 on the ones I use regularly. But I consider that stressing them. It makes a lot of sense if you think in terms of material science, not in terms of spec sheets we have all come too familiar with. 3.6v would be a bit better, but screw that. I keep the batteries around for a reason.
Despite what it is said there (60 - 65% of available stored energy left at 3.9V), after taking a look at some of HKJ's discharge graphs and doing some math (average voltage × capacity sections), modern cells still hold above 70 - 75% of the available energy at 4.2V if stored at 3.92V for loads rated at around half of the maximum recommended continuous discharge current. This is fine for me.
Heck, I am going to convert my inexpensive hairclipper to li-ion cells and I am going to fix the charge voltage to 3.92V with a CC/CV buck converter. Zero worries with cell wear out, it's gonna be a massive performance upgrade anyway: from 2S AA Ni-MH to high current 2P 14500 li-ion.
