A123 5s or 6s runtime question

Hi guys,

Was just out at the track today with my newly converted B-Revo, which ran awesomely. Its running a Mamba Max ESC with a CCBEC and a 8XL motor. ESC and Motor were warm after putting 2 battery packs through so I'm happy with that setup I guess.

My question is this. I was running 5S A123 2300mAh packs. If I go up to 6S (my Monster Mamba Max is still coming, if the Mamba Max can't handle 6S), will I get a little more run time? I know if they're in series, I'll get more voltage , but does anyone know if the runtime will change at all?

The reason I ask is that the club I race at does 6 min races, and so with a decent run, you can put in 6-7 laps, 8 if you're very fast.

The first pack today died about half way through the 6th lap, and the 2nd died just before finish line to complete 7 laps.

thanks!