I had previously considered using a pair of
Boost step up converters to produce a consistent 60V output across the entire battery discharge range using a small, lightweight
(and lower voltage) LiPo battery pack.
Using two of these with a 48V pack should work, but you would need to monitor the battery voltage
(not the output voltage) during use to determine how much battery capacity remained.
Two of the above boosters wired in parallel should be able to produce a continuous output current of 30A @ 60V, which is the maximum that a single Magic Pie will draw with a standard controller.
You would need to accurately set the output voltage of both boosters to the same
60V before connecting the outputs together in parallel to ensure they shared the load evenly.
If it was constructed into a stand alone unit that simply plugged in between the battery and the controller's battery lead using the same style Anderson connectors, it could easily be bypassed in the event of an unexpected failure, so that you are not left stranded without motor assistance.
It would also need adequate airflow to ensure the units did not get too hot.
My biggest concern was whether regen would cause problems, as I don't think it would be possible to feed current back through the boosters.
It may be possible to use a high current relay
(operated by the brake switches) to automatically switch the positive motor lead from the booster "
+ output" to the booster "
+ input" while braking to allow the regen current to flow back into the battery.
Now you've got me thinking out loud too.
Alan
