RE: GP3300 charging
as long as it can handle 7 cell nimh, it should be ok. I don't know if either one of those do. I use MRC superbrain 959, and it works fine to 8cell. I also have dual charger. most of the better car chargers out there can charge upto 8 cell nihm.. if you want lithium capable or more than 8cell, the price will go up...