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pweekly's avatar
pweekly
Explorer
Aug 25, 2018

Generator draining chassis batteries

Hi all:
We have a 2005 Mandalay 400HP Cummins and don't use it a whole lot. (although have been better this summer). We take it yearly to a football game weekend and use the generator. Sevel times, while running the generator from a Friday to Sunday morning, the chassis will be dead. I am thinking that the generator is running off the chassis so rather than charging it up, it is slowly draining it. the house batteries are fine. I started the generator and if I switch the chassis batteries to the disconnect, it kills the generator (leading me to think what I do about them working together for more than just powering up the penny).

So, given that we are going next weekend on a football weekend, would attaching a battery minder like the Noco Genius to the chassis batteries solve my problem (if only temporarily).? Any other ideas you can think of? Thanks so much.
Trish

13 Replies

  • You mite look into a Trick-L-Start, or for this week-end just get two large alligator clips and some heavy wire and hook the pos house battery to the pos starting battery when the generator is running and take it off when it isn't running
  • Our Onan generator does not charge the battery. It uses the battery to run the 12 volt items on the generator ( fuel pump etc). If 12 volts is disconnected the generator shut down. The Inverter/battery charger in the RV charges the battery when running off the generator or shore power. Your might be the same check fuses. Until you find problem you can connect a 110 volt battery charger to battery to keep battery charged. We have done that when our inverter burned a circuit board.