i loved my old packs, havn't run these packs yet. i'll run the truck on saturday to make sure it's in check, and race sunday. yep, parallel. 10,000mah and 100/150 amps. conservatively. i've yet to run the truck till the batts run out, but i'd estimate 30min w/ the 4000mah packs. dunno about the 5k's.