Why would you need a new controller?!?!? and thats for one pack. the 2P means that there are 3 groups in series of 2 cells in parallel.

You would need two of those packs.

I guess i thought i would since the burst is at 128 amps. the 9920 is only at 95 amp rating. but, i may not totally understand all that. So if i ran one 3s2p and one 2s2p at 8000 mah with the 9920 that would work? Making it a 5s lipo 8000 mah?

Yes, that would work. Don't try to correlate the battery's amp-handling capabilities and the 9920's amp-handling capabilities, they have nothing to do with each other. What you do need to work with is the motor that you're using.

I have the 10xl wanderer...As the other thread i started, here is my end thought....one 3s2p 8000mah, one 2s2p 8000 mah bringing me to i think 18.5 volts in series wiring and balancing my truck. So, here would be my set up: 9920/10xl with 5s 8000mah lipo with UE diffs and 40 series tire. what speeds would i be looking at?

About 52. About 59 on 6S LiPo

Ok. The reason i ask is because I have the UE diffs. And after putting those in, my truck seemed considerbly slower. I'm assuming because the gear ratio changed (duh). So I bumped up my pinion to an 18T. I ran again last night(second run), It still seemed REAL torquey(if that's a word), but added some speed. My temps are still down pretty good so I'm gonna try the 20T I have tonight and see what that does. FYI 20T/51 spur. Does Ofna make a smaller spur that I could use with the strobe slipper to add more speed if I wanted to try that? But this is without the LIPO, 16 ib3800's. thanks for all the help guys!
Squee: When did you become a MOD?

I think Mike might be able to get you a bigger pinion if need be. And no, there aren't any more spurs :frown:. Oh, and I've been a mod for about 2 months :p.

For some reason, i never noticed until last week, just never asked i guess! Great JOB! Thanks for all your help on LIPO once again! I think i may have a pretty good grip now!

No problemo man!