Motorhome charging toad battery

[High Ball]

I just installed base plate, transmission oil pump and finishing final touches on wiring for Even Bake system, I want to install a feed wire to charge the battery on the toad. I don't want to run toad engine at end of day just to make sure battery will be good for the next.
My question is what gauge of wire to use and amps for fuse. I know I should put a fuse starting at MH batteries but do I also install one before the toad battery ??
Thanks for the info

[George Z]

Definitely install a fuse on both ends of the charge line. The toad battery can cause a serious short issue as well as the charging vehicle

[Cobra1]

Remember the alt in rv is going to try to give whatever the car battery can take. I would run a 10gage wire with a 30 amp fuse. That should handle most loads unless the battery is like 1/2 used.

[jrd48]

Use #10 wire with 30 amp fuses (or circuit breakers) at both batteries or #12 wire with 20 amp fuses (or circuit breakers) at both batteries. I used #12 wire with breakers and that works fine for my requirements.

[High Ball]

Thanks very much. Will go with the 10 wire and 30 amps breaker.

[Stealth01]

Consider this: RVibrake Towed Battery Charger, charge line replacement