mjk1040 wrote:Source of the post....Thought I saw 3 separate feeds coming off the OEM ACtoDC charger to the three OEM batteries....
Correct, but when you set the selector switch to "BOTH" you are connecting "both" banks together electrically, that's what the switch is designed to do in that position. When you do that, it's like having one big battery, but now the two banks aren't isolated, they are combined. It won't matter where the charger legs are connected, it all becomes part of the same circuit no matter where in the circuit things are hooked up. It would be like hooking up 2 charger outputs to one battery. This confuses some chargers as the two outputs now hooked to the same bank electrically may conflict with one-another. While the two outputs are trying to output a charge of say 14V, each may see 14V already there from the other leg thus think that the battery/bank is charged. Some chargers may be able to deal with this, but some go into a float mode right away or keep cycling on and off, while some chargers shut down completely (all outputs) because of the conflict. The cycling on and off is like trying to start your car on a dead battery. The clicking you hear is the starter solenoid engaging, when it does, the voltage drops even further and causes the solenoid to disengage. When it disengages, the voltage rises again engaging the solenoid again, when it does, the voltage drops again, and so on.....cycling on and off.