just for the batteries:
@flecc:
what are "very heavy batteries" in your eyes ?
the batts he has mounted are
36V (nominal in real is 33V)
9,2Ah
weight should be around 4 - 4,5kg
its one of the few bikes that use real good batteries so
batteries where you can expect many years of use and very high cycle-rates (over 1000cycles in such a bike for sure, even when you run them down from 33volt to 20Volt or 15Volt each time of use)
using 4packs of the Dewalt-kits seems to be easy for the designer of this conversion kit,
but it is also some nonsense:
1.) you need 4 chargers, or you need to charge them one by one
2.) each pack carries his own balancer with it
--> when you remove this you can safe ~300g for each pack
balancing is not realy needed for that cells.. if you want to be on the safe side, do it maybe every 30th charging process
so: the balancer-unit should be placed with the charger in your garage and not in the bike were you have to carry it around with you