Battery Connections
If it is a OEM converter, the DC off of it could be "rough" and possibly damage LEDs or electronics. If you can connect just one battery utilizing small C-clamps or large clips (like a battery booster clamp) just to make a decent connection and ensuring you do not draw too much power. Just be careful working with the battery.
If you have a quality Inverter c/w charger, you may be able to run w/o a battery.
__________________
|