I have a king quad and the battery went dead. Would not hold a charge and only showed 6volts after being on a charger for 24 hours. I replaced it with a brand new one, and fully charged it. A little over a week later the battery is again dead. I just measured it and it's at 4.3 volt when in circuit. There are no add on electrical accessories. What can kill the battery when it's just sitting in there and connected. Would appreciate any points as to where to look. -Thanks.

Update: I removed the battery and measured 32k ohm with the switch off across the positive and negative battery terminal wires, 16 ohms when the switch is in the on position and 1.6ohm with the switch in the head light position. I would think that with the switch in the off position I'd see something more in the Meg ohm range. The battery measured out of the ATV was just over 4v so am trying to charge it again.

 

There appears to be a draw on the battery when the quad's key is in the off position.With the key in the OFF position, disconnect the neg. cable from the battery and connect the positive lead of a VOM to the neg post on the battery. Then, connect the Negative lead of the VOM to the battery end of the negative battery cable. Set the VOM's DC amperage to 5 amps and take a reading. If the VOM shows a current (amps) value you have a Negative draw. In other words, some component, ie stator, headlamp, taillamp, horn circuit, etc is providing an easier path back to ground potential. Current is leaking back to ground and discharging your battery. If your VOM shows a value on the display, with the VOM connected "in series" with the battery as described above, begin carefully disconnecting the various circuit connectors on your quad. Some of these circuits are: the main wiring harness that comes from the frame and connects to the motor, the connector on or near the handlebars that feed the headlamp, the connector near the rear of the quad the goes to the tail light, etc etc. If you see value on the display of the VOM drop significantly when you disconnect a wiring harness connector, you have found the circuit that is draining the battery. It could be as simple as replacing a burnt out and shorted tail light / brake light bulb or cleaning a coroded connector or straightening a bent tab in a connector.

 

I think I may have found a bad regulator/rectifier module. When I disconnect it the battery has stayed above 12v. When it's hooked up then the voltage continues to drop at a slow rate.