1) do i connect the fpex2 balancers to the battery while charging ???
Yes, they are the best balancers for those batteries.
Once the individual light starts flashing it means the cell is full and is no longer charging. Once all 10 lights are flashing simultaneously it means all 10 cells are not being charged.
2) or do I only need to use them once in a while ???
You dont have to use the balancers always.
Try every 5 charges
3) what is the best setup for the chameleon 6-330d charger ???
I have the same charger, not sure what you mean by best setup?
That charger will not be able to charge that battery at 4Amps. I think 3 Amps max. But thats a good thing, in my opinion.
I work so I can fly