Thanks for the quick answer.
Could you please explain what do you mean by "5 heat cycles" ?
Is that heating the engine 5 times ?
During a race day i have to start the engine at least 6 times (practice, 3 quals, semi, final).
The benefit i see with the 12V version is to be able to use it when there's no 110/220V available at the track.
So it means that i will have to get 2 lipo packs.