Charging a towed vehicle's battery

[fwtraveler1]

I can not get my RVI battery charger to work towing my 2020 Chev Equinox. Is there another/better system out there for charging a towed vehicle behind an RV?

[willald]

It is true that the MH will have an 'always hot' pin in the back, usually part of the 7 pin connector back there.

HOWEVER, as someone previously stated, do NOT assume that said pin is indeed hot. Check it with your voltmeter!

On Ford's F53 chassis, they do NOT wire that pin to 12V power from the factory. Neither do most RV manufacturers. We learned this with our Newmar we just bought a few months ago.

On ours, Newmar *did* run the wire from up under the dashboard, right out to the 7 pin connector at the back; They just didn't connect it at either end. I had to do that, before the charge wire would work.

Sooo, whether you use a simple charge wire or some kind of charger...Don't assume the wire thats supposed to be always hot, is. Check it with the voltmeter first.

[dodge_guy]

The MH should have a pin that’s 12V hot when the engine is running. I use a 6-way at the toad (standard for RV use). However some cars require the battery to be disconnected to tow. With that you could get a small lawnmower type battery and wire it in as a dedicated battery for he brake controller and run the charge wire to that and run a 12V outlet for the brake system.

[lryrob9301]

fwtraveler1 wrote:
I can not get my RVI battery charger to work towing my 2020 Chev Equinox. Is there another/better system out there for charging a towed vehicle behind an RV?

Are you pulling the fuse for the rear windshield wiper as per instructions?

"NOTE: Towed Battery Charger Plus is compatible with all 12 volt batteries including trailers. 2019-present Chevy Equinox must pull rear windshield wiper fuse."

[obgraham]

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.

[bighatnohorse]

I'm currently installing an Invisibrake system and I have run a charge wire from the truck battery to the tow'd.
The hot wire is fused at both the truck and tow vehicle batteries.
The hot wire is always hot.

[JRscooby]

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.

[mowermech]

obgraham wrote:
In the receptacle on the motorhome there is an "always hot" pin. At least there was on mine. I had them run a separate wire from that pin directly to the toad battery.

THAT is the best idea! Yes, it will require a 7-pin plug on the toad, but that is easily doable. Be sure that "always hot" pin is wired with 10 gauge wire from the power source in the motorhome all the way to the toad battery, and be sure there is a 30 amp fuse or circuit breaker installed in the line at the motorhome power source. Higher amperage may be required.

[jdc1]

Just toss a solar charger on the dash.

[CA_Traveler]

It could be defective, mis wired, inadequate wiring, no input from the MH. A voltmeter is your friend.

[Lwiddis]

Excellent suggestion IMO.

[obgraham]

In the receptacle on the motorhome there is an "always hot" pin. At least there was on mine. I had them run a separate wire from that pin directly to the toad battery.