Charging RV battery while driving

[davidsp]

2004 Wildcat 5th wheel, the owners manual says charging the battery charges when plugged in to a pedestal or from generator. While driving if I ran a wire from the running lights to the battery would this charge the battery when the lights are turned on.

[bikendan]

Hi and Welcome to FRF!
Your trailer 7-pin cable should provide a charge from your tow vehicle IF you have your truck enabled to provide a charge. Sometimes a fuse or relay needs to be installed. You need to check your truck's 7-pin outlet and see if that pin is working.
Be aware that most tow vehicles only provide a trickle charge at best.

[babock]

If you really want to charge your trailer batteries while driving, run a large gauge wire through a fuse or circuit breaker from your truck battery to the bed of the truck. Use a high current connector like an Anderson connector and then run a large cable to a DC to DC converter charger that sits as close to your batteries as possible.

Here is a 40A Renogy version.
https://smile.amazon.com/Cargador-ba...0693211&sr=8-3

[TitanMike]

Originally Posted by babock

If you really want to charge your trailer batteries while driving, run a large gauge wire through a fuse or circuit breaker from your truck battery to the bed of the truck. Use a high current connector like an Anderson connector and then run a large cable to a DC to DC converter charger that sits as close to your batteries as possible.

Here is a 40A Renogy version.
https://smile.amazon.com/Cargador-ba...0693211&sr=8-3

Amen to the above. I got the Renogy 20 amp unit because my TV alternator is somewhat smaller than many vehicles come with today. Charges my Battleborn Lithium batteries in the average drive time between boondocking spots, usually at a constant 20 amp unless batteries are close to full.

[TitanMike]

Originally Posted by babock

If you really want to charge your trailer batteries while driving, run a large gauge wire through a fuse or circuit breaker from your truck battery to the bed of the truck. Use a high current connector like an Anderson connector and then run a large cable to a DC to DC converter charger that sits as close to your batteries as possible.

Here is a 40A Renogy version.
https://smile.amazon.com/Cargador-ba...0693211&sr=8-3

Amen to the above. I got the Renogy 20 amp unit because my TV alternator is somewhat smaller than many vehicles come with today. Charges my Battleborn Lithium batteries in the average drive time between boondocking spots, usually at a constant 20 amp unless batteries are close to full.

Also could work in the unlikely event I need to charge the batteries to make it through a nite by hooking up to the TV and letting the engine idle for an hour. If I ever needed to do that it meant my generator and solar panels were inoperative for some reason but it is a third level backup.

[rsdata]

I would also think that recharging current provided by the engine alternator would be limited somewhat by the capacity of the alternator and the electric being supplied to run the automotive needs at the time. I know sometimes when purchasing tow-ready trucks they come with high-output alternators, but I do not know what spec that meets.

[babock]

What limits the charging is all the voltage drop in the wiring between the battery and the 7 pin connector.

Originally Posted by rsdata

I would also think that recharging current provided by the engine alternator would be limited somewhat by the capacity of the alternator and the electric being supplied to run the automotive needs at the time. I know sometimes when purchasing tow-ready trucks they come with high-output alternators, but I do not know what spec that meets.