Typopanther wrote: ↑
Dec 23, 2017 6:17 pm
I imagine I could switch to 60AH cells but that would require a new BMS
It shouldn't require a new BMS. If they are the same kind of cells, and the same number in series, and the output current is the same (just greater capacity total), the same BMS can manage the larger cells. It might take longer to balance them if they aren't good cells and don't stay in balance, but that's the only thing I can think of that would be any different.
If you have the room (probably not) you could even wire the 60Ah in parallel with the 40Ah at cell-level, and use the same BMS for both.
You could also try out some aerodynamics improvements, and see how much that reduces your power usage. Tailsock, taller/wider windshield, etc.
Additionally, at those speeds, if it's possible to go just 5MPH slower, you will also extend your range by reducing power usage. Probably not practical for a commute, though.