[jhautz]

I did what you are trying to do for a while untill I upgraded my charger. You just have to make sure both packs are topped off, balanced and show the same voltage per cell when you start. I never had any issues, you just need to pay a little closer attention when chargeing and balancing is all. BTW. I have a few sets of the TrueRC 8000 3s+2s setup and really like them for the $$$. Let us know how they work out for you.

Also with the 977 you can charge both packs at once. It has 2 outputs and they can be used at the same time. The 977 limits the amps youc can charge lipo with to 4 amps on a 3s pack and 3 apms on a 2s pack. But it can handle running at this load on both outputs at the same time. That should cut down you charge time a little.

As GD said, the 989 is a really nice upgrade. You can then charge with a Y adapter and a modifed 5s balanceing tap and charge them at the same time as 5s packs.