Well I just received my "36v 20ah" battery from the seller of the kit you bought..
The reason I put the 36v 20ah in quotes is because this battery LOOKS SMALLER than me 36v 15ah battery and weighs less...
I will be testing the supposed AH rating tonight and will give you all the details..
The 36v charger that came with it , seems to be an SLA charger..
I'll test that out too.