I bought a bunch of 40AH lithium cells that had been lightly used, this is a shot of 42 of them on the bench.
I strapped them together in parallel to equalize them and charge all at once with a bench supply.
A full week was needed just to raise the voltage to 3.69 from 3.3V, not surpising with a combined AH of 1680 or so.
I purchased a miniBMS setup from Cleanpowerauto.com to stop the charger if any cell gets charged above 3.8V.
The BMS will give me a method to terminate charge, as well as an alarm to indicate a low cell while driving, but I don't plan on that depth of discharge.
I also purchased a cycleanalyst to keep track of amp hours out and in. While not a real necessity, it will make tracking my charge much easier. The stock meter will go to zero and I will still have capacity, I could ride to zero and recharge and all would be fine. The stock meter is set to 32AH so I would use 80% of the 40AH battery and stay within the safe range but I like the idea that I can keep an eye on things and if I need to stretch my range I can keep track.