I have two 12v 28ah batteries in my Tiger1 they use up a bit of space but it looks like I can almost run all day. At a recent model show I drove it around all day with half hour breaks . When I got home that night I tested the batteries and they still showed over 24v . The tank went well but I still can't activate the gun noises with my Spectrum dx7s but I have the engine noise so I'm happy with that at the moment .
RGDS Wolfgang