The other problem alistair is that at 36v they will be pulling nearly 40amps at stall. Thats alot of current and will need a Big speedo to deal with it.
They will also get very hot. Realistically to run golds you will need to use 3amp sanyo cells. These are quite heavy and would weigh 2.85kg.
Another problem with 36vs is a supernova (or replacement) will not charge those batteries.
So perhaps sticking with 24v is a better idea.
Regards
Ian
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