connect coach and house batteries?

altblank wrote:

hornet28 wrote:
You have a drain someplace. Use a battery shutoff on the coach battery

agreed totally, there's a definite drain somewhere. but a shutoff means i'm wasting the excess solar power that's generated for free, and i'll just be that bit closer to having the engine battery work better... but not quite.

thanks!

You're not wasting solar, you just aren't leveraging it for charging your chassis battery (coach and house batteries are the same thing). And you shouldn't have to. And a shut off would stop the drain. You wouldn't continually run water to fill your FW tank because it had a hole in it would you? You would find the leak. Your Chassis battery (like any car or truck) gets charged by the alternator when running and if things are working as they should, should not need recharging for a reasonable amount of time. A week is unreasonable. House/coach batteries however get used while camping and thus the reason for the solar charger to keep them topped off.

You are attempting to put a band aid on the problem. You need to find the reason for the chassis battery drain. Or at a minimum, install a shutoff to stop the drain.

On edit - something to consider with your proposed solution of linking the House and chassis batteries together to benefit from the house battery solar charging. Whatever the draw is on your chassis battery could be strong enough to now also drain the house batteries in spite of adding them to the solar chain. The point is that you don't know what this draw is causing the chassis battery to be drained in a week. And if you don't know that, you don't know that the solar which would now be required to charge yet another battery, is enough to offset that drain. You could potentially exacerbate your problem by spreading the drain to the house batteries.