Will a small 12v battery work?

[MADMAX2]

I have built a circuit in the car for an accessory and need the smallest 12v battery to power it I don't want it powered from the car battery ( too much hassle long story!!!!) I have found the small aa type 12v battery but shorter which would be perfect size but would it power the circuit if I connected a pos and neg to it? It's only for a light in a very small space I tried it on a small 12v motorcycle size battery and it worked I need it to be as small as the aa style 12v battery as there is no space


Will the small 12v battery work?