[suicideneil]

Well, the numbers are in, and:

8.4v (2s lipo at full charge voltage) x 5amps (full current 1c charge rate) = 42watts, so if you charge both batts in series as one pack, you're looking at a saving of ~20% in terms of charge time compared to doing the packs seperately. For the hassle, it would probably be easier and alot quicker to just pickup another charger- they sell for £48 on modelsport, then you'd just need another balancer.

Im personally never in that much of a hurry- charge up all my packs the night before, then have a few hours fun until all the packs are dead- if you race or want more fun time, then a more powerful charger or more batts might be in order..