Aren’t you even curious whether they are good cells? Might as well open it now just to check the cells out and then charge them to 3.6v (50%) for long term storage.
IMO, definitely pull them and charge. I bring my samsung pack-pulls up to 4.30V resting then let them sit for a week before rechecking. If they hold 4.28-4.30, they’re good. All my cells are in a rotation and get stored at 3.7 - 3.8V. I Have not found a bad one yet, which is pretty amazing.
Mine was $17
Some more for sale cheap. Look here;
Came across a couple more of these packs for sale on eBay for $16.
I think I have enough packs for right now, so when I come across intriguing new, old-stock laptop pack deals I’ll be posting them to this category, on my blog (and on BLF, when I have a chance)
The above is quoted from RMM a few posts up. Not sure why it’s not showing up right.
Lifetime of the cell increases when charged to a lower voltage. Back in the day, common knowledge was: charging a LiIon to 4.2V would give you approximately 300 cycles while charging them to 4.1V would give you closer to 800 cycles. I’m sure charging 4.3 V cells to 4.2V would only increase its lifetime. (some laptop brands have an option to charge their batteries to a lower voltage to increase battery life)
That sounds inflated. The rule of thumb I’ve seen is that life doubles with every 0.1v reduction in charge termination voltage. Still an improvement, but 2x is significantly less than 2.66x.
Its worth keeping in mind though, that the rechargeable battery is just part of a system. A 0.1v reduction in charge voltage results in a sacrifice of about 10% amp capacity every cycle, which means more charge cycles, which eats up part of the increased cycle lifetime. It also results in a greater reduction in energy capacity, because 280 mAh at an average voltage of 4.25 (beginning of discharge) is 1.19W, where as the same 280mAh 3.2v (near the end of discharge) is only 0.88w. Moreover, the current required to deliver a given amount of power also goes up, which means more heat and stress too. (The current/power relationship isn’t an issue with a linear regulator, it is with a switch mode regulator).
A bigger issue might be philosophical: Is the user supposed to serve the battery, or is the battery supposed to serve the user?