I have an electric motorcycle I built out of a 1995 Suzuki GS500e.
Right now it has four Optima Yellow Top AGM batteries in series giving me around 48v of power.
I want more range out of the bike without sacrificing performance, so I have been looking into Nissan Leaf Li-Ion cells. They're cheap, small and stackable.
At 7.6v each, I'd need 8 of them to get me to where I am, and as I hone in on my desired range, I will just add batteries (my AXE controller allows scaling).
Through all of my research, I can't figure out the best way to charge them while connected in the array (safely). Presently, I have an on-board charger and I can plug in at Level 1 EV charging stations, i'd like the same for the Leaf batteries.
What would I need to do to accomplish this?
Best Answer
Li ion batteries are charged with balancing in mind.
simulate this circuit – Schematic created using CircuitLab
In the schematic imagine that the voltage sources are batteries. In the first schematic a bunch on cells are in series. The cells are charged by some high current source. The cell voltages are monitored by balancing circuitry. The circuitry will bypass some charge around cells that are more charged than others. The circuitry reports to the high current source letting it know how the cells are doing and what mode to charge the cells in. The starting mode is constant current and when the cells reach a predetermined voltage the mode switches to constant current.
This setup scales when adding more cells in parallel.
You would need to buy a charger that connects to the batteries as described. That can talk to a charging station. That supports balancing lithium ion cells.