An RVer converting to LiFePO4 batteries asked how to add a DC-DC charger, why the existing charging/boost solenoid needed disabling, and whether the chassis battery positive could supply the charger. A responding member explained that the solenoid connects the chassis and house batteries during engine operation and for emergency starting assistance. The RVer concluded that disabling the automatic connection would prevent charging from bypassing the DC-DC charger, while a switch in the...
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An RVer converting to LiFePO4 batteries asked how to add a DC-DC charger, why the existing charging/boost solenoid needed disabling, and whether the chassis battery positive could supply the charger. A responding member explained that the solenoid connects the chassis and house batteries during engine operation and for emergency starting assistance. The RVer concluded that disabling the automatic connection would prevent charging from bypassing the DC-DC charger, while a switch in the solenoid control circuit could preserve emergency battery boost. They planned to supply the charger from the chassis battery positive.
The responding member emphasized checking the actual wiring before modifying it, particularly because three-terminal and four-terminal solenoids have different grounding arrangements, and older components may have been replaced. A separate question about the heavy cable to the generator was answered as its 12-volt starter supply, distinct from the generator’s AC output feeding the converter. The exchange clarified the intended approach, but no completed installation or test results were reported.