New Car project, with budget.

Looks like that I take HongNor X1CRT Pro to my project ( same as Ofna Jammin truck ) .

But, now I am thinking about the batteries. Is those hobby-city's Zippy packs really safe choose to this project ? I really hope that those batteries won't get damaged and get smoked if I choose them.

But the problem is that those Zippy packs are over if I need 5000mAh packs... And I don't know what is good voltage for 1700-2200rpm .