charging a battery

[wgr]

Any of you guys know of a way to keep a battery charged on a car that's being towed.

[rl69]

.???? Not sure what your need is. If you need to run flashers you can get tow lights that run off the pull vehicle.

[wgr]

need to keep the battery charged at all times on my towed car. would like to run the cars signal lights also. will be towing behind a motor home

[Tracy]

The motorhome should have an auxiliary 12V output in the trailer connector.

[bangerjim]

Get a 12v solar panel at HF. Mount it on top of your motor home. Wire it to the car battery and your battery will be trickle charged when the sun is out.

https://www.harborfreight.com/15-Watt-Solar-Battery-Charger-68692.html


Banger

[rl69]

https://www.etrailer.com/faq-wiring-kits-for-vehicles-being-towed.aspx

[rockrat]

I had gotten a setup that you run a harness to the back of the towed vehicle and it connects to the rear lights. Up front , hook it to your trailer connection and you have left/right/stop and running lights at the back. Doesn't mess with the towed car battery.

[Paper Puncher]

If you have a 7 pin trailer connector on the motor home one pin should be 12v. You can connect to this pin and run a wire (suggest 8 ga) to the cars battery. Make sure both ends are fused (at the motor home and at the car). Two 20 amp fuses should be adequate. The connector on the motor home may already be fused. A good ground to the car is important.

[Driver man]

I have a lead I made up with a cig lighter plug on each end. I plug the towed vehicle into the towing vehicle through their respective cig sockets. As long as I don't draw more than 10 amps everything in the towed vehicle works just fine.

[Tatume]

If your battery is depleted after only a few hours (8-10) being towed something is wrong. You should locate the source of the battery drain. Or perhaps your battery is defective.

If you have a good battery and you just don't use the towed vehicle very much, then do what I've done. Get a $10 battery charger and mount it inside the engine compartment. When you are stopped for the night, drop an extension cord to the battery charger and let it charge over night.

The charger I'm talking about is a compact, solid state device with no switches or controls. I have them in two and three amp charging capacity. My under-hood charger is mounted with zip ties. Works just fine.

[wgr]

my towed car must be in acc. if that makes a defferance

[metricmonkeywrench]

So just to set the conditions completely you have not made any connections yet and as I understand it you are flat towing with a tow bar nesisating the need to have the towed vehicle ignition in accessory position to unlock the steering lock and allow it to trail without dragging the tires?

May want to consult with an expert as some states require electric brakes and a breakaway on the towed vehicle when flat towed. As a part of that install marker/brake lights are normally part of the package.

Marker/brake lights are easy enough to tap into the towed vehicles system so ling as you can identify and get to the appropriate wires.

[rockrat]

Don't know what vehicle you are towng, but my Jeep Liberty, I can turn the key to unlock the steering wheel without going all the way to ACC.

[wgr]

2018 Cherokee it had to have a switch attached so that the steering would have power at all times guess ill go to a dealer

[leadman]

I tow my wife's '98 Chevy Tracker behind our motorhome on a dolly and I have to disconnect the battery as there is no key position that unlocks the wheel without power turned on.
In your case it should work to put a battery disconnect switch in the car and run a cable from the rear of the motorhome to a point on the towed car to work the lights. This way you have lights without the possibility of other accessories on while you are towing and the battery should stay up. If you aren't concerned about other accessories just run a fused positive and negative to the towed car battery from the coach.