Once again, dual battery prob.

[ClearStorm]

Here is my problem, When i go to charge my zip(with dual batteries), it doesn't work. BUT i have a 3.0 volt 700mA custom charger. It seems my zip will only charge while the LED is on orange(red), but it is extremely hard to get the zip on orange. And when i try to keep it on orange it will turn green after 30 seconds,and the car will only run for 30 secs before dying out. When i went to check all the connections, everything was fine, but i did notice that the negative terminal for the car was loose. I am now thinking that: 1.) I have fried one of my batteries, or 2.) it just won't charge. What do yall think is wrong? Help would be appreciated.

On a lighter note, the dual battery mod worked the first time i tryed it and it was doing barrel rolls everytime i would attempt to turn and it ran for at least 15 minutes, but when i woke up the next morning i got the problem that happened above.

P.S. thanks to epochracer for his help