Battery Question for a G&G M4 Electric Blowback

So I just got a new G&G M4 Commando Electric Blowback and bought a 9.6v 2300mah crane stock style battery and for some reason I can't get the battery to operate the gun. Thought it might not be holding a charge but had it tested at Batteries Plus and it's just fine. I hooked up another battery I had that was a 9.6v 1600mah and the gun worked just fine. Any suggestions as to why the bigger battery wouldn't work?

try looking at the connector, that could be the problem.

I even tried the new battery (9.6v 2300mah) on a different gun of mine and it worked just fine. For some reason it just doesn't like the G&G M4.

IF Fuse install check it, Fuse okay then remove you End motor plate and ensure wires to motor are still connected. If wires are still connected, then it's a internal problem with gear box wiring