Best use for excess electricity on a bike?

[pete c]

Since it will be fully enclosed, perhaps you can have enough cells to have a small bit of surplus electrons.

I think this would be best used by increasing your battery size a bit to a modestly sized deep cycle to ensure longer alternator off driving during cloudy/night driving. Not sure I would use this to power much other than maybe a laptop for a short period as it will run the battery down quickly and shorten its life.

[Ryland]

average sun hours in the USA is between 3.5 and 6 depending on where you are, 4-5 is most common, so really if you plan to ride for 4-5 hours per day (120 to 300 miles, depending on speed) you could very easily use up any stored energy, like I said before, I'd be tempted to run at a higher voltage and have a step down converter to run the motorcycle, BMS's on lithium batteries tend to have a low and high voltage cut off control so you don't kill the battery, hooking it up to a DPDT switch to turn the alternator back on would allow you to run 99% of the time off solar with a safe cheap back up.