Generator draining chassis batteries

pweekly wrote:
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

First thoughts are that something else is on and draining the chassis batteries.
The Genset doesn't run off of them, except for maybe providing excitation and control voltage.
So, I'd say that the Big Boy Relay or other, isn't closing, as it should and thereby is incapable of charging the chassis batteries.
Do you have a voltmeter handy and what are the readings for the both the house and chassis batteries? Also what change in voltage is there, with no outside power and with the genset running?
Does it stay charged with shore power?