Charging a towed vehicle's battery

JRscooby wrote:
Not sure "always hot" is the best idea. I think a better idea was have the charge pin controlled by the ignition switch of MH. (If it ain't running, it won't charge anyway)
And the toad end can't be mounted solid, unless you use a removable cord. A switch near toad battery to disconnect would stop a hot wire from causing trouble when not towing.

Indeed, I mis-wrote in my post. The "always hot" pin was wired to the ignition-controlled circuitry on the MoHo. I don't really want it charging when the rig is shut down.
The MoHo had the 7-bladed plug, and I used an adaptor to go to the more typical 7-pin plug to connect the toad.