hi all,
I have a motorhome with a leasure battery that charges when on mains electric hook up, the charger doesn't charge or maintain the engine battery in any way. The engine alternator charges both batteries.
I have an idea that if I put a high power doide and maybe a current limiting resistor between the positives of the 2 batteries the engine battery can be trickle charged by the hook up but can't be discharged by the TV etc.
What do you brainy people think? I realise there will be a 0.7v drop over the diode but it should still work ok. Unless I'm missing something.

 

I'd say this comes close to an automotive modification, which is not allowed on this forum. The forum owners have decided not to host discussions of automotive mods, and ask that you respect the decision. It is stated in the Terms of Service, in section 6.

 

i promise I won't sue anybody...

How sad...

Ok delete it then

 

I would think a $20 AC powered automotive battery trickle charger would be well worth getting here.