I just installed a 48 V ebike conversion kit on one of my bicycles. I will power it with 4 12 V, 12 Ah, lead acid batteries connected in series because of the cost of 48 V, 12 Ah lithium batteries designed for the purpose. (I may buy the lithium batteries later if I find that I use the bike regularly.)
My question is in regards to charging the batteries. It seems that I have three choices:
1) Charge each battery individually with a 12 V charger.
2) Charge them in parallel with one 12 V charger.
3) Charge them in series with a 48 V charger.
I currently own two 12 V chargers and no 48 V chargers. I am thinking that charging them in two banks of two, in parallel, would be my best option without buying more chargers. Any comments on the pros and cons of any of these options would be appreciated.