[tc3_racer_001]

a123 are pretty much the safest battery...
u over charge it, they just die, no fire or exploision...
u over discharge it, o well, just dont do it too much or it will lose capacity
u charge it too fast - i doubt u will be charging it faster than 40A anyway! (10A - 15Aper cell(in parallel) is recommended)

and if they get punctured then they dont catch fire!