Can Camper Battery be Charged While Driving by Running Wire from Vehicle Battery to Camper Battery
Question:
I installed one of your solenoids on my pickup and wired it to the camper batteries, about 25 ft of 8 gauge. Were just running a small freezer in the camper Max 3 amp draw. While were driving the system appears to remain stable, that is the batteries do not loose charge. However, they do not seem to charge. We get 14.5 volts at the trucks battery but only 14 v at the campers battery. Do you have any idea as to why the camper batteries do not appear to charge up while were driving? Do we need a bigger cable? Any help would be appreciated. Thanks
asked by: Martin
Expert Reply:
The distance from the vehicle battery/alternator to the camper battery is too long to be able to charge up the camper battery. Going to larger wire will not help and can actually make it worse. Pushing back the required amount of amperage, not voltage, to charge up the battery would require a powerful alternator and large enough wire, like battery cable only maybe a little smaller, and it just isn't really feasible on a passenger vehicle.
The only sure way to charge up the trailer battery while you drive is to use a DC to DC charger, # 331-BCDC1240D as an example, either connected to a 12 volt circuit in the trailer connector or to the vehicle alternator.
If you want to save some money you could instead use an AC charger, # CTEK56353, when you have access to shore power. I own this charger and it works great. I have linked videos of both chargers for you.

Products Referenced in This Question
Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp
- Battery Charger
- Battery Charger
- RV/Camper
- Trailer
- 200 Ah
- Charges/Maintains
- DC to DC
- 12V
- Solar Panels to Auxiliary Battery
- Vehicle Battery to Auxiliary Battery
- Redarc
more information >
CTEK MULTI US 7002 12-Volt Universal Battery Charger w/ Pulse Maintenance and Backup Power
- Battery Charger
- Battery Charger
- Car/Truck/SUV
- Motorcycle
- Trailer
- Lawn Mower
- Jet Ski
- 150 Ah
- Charges/Maintains
- AC to DC
- 12V
- Wall Outlet to Vehicle Battery
- CTEK Power Inc
more information >
Product Page this Question was Asked From
Starter Solenoid - SPST - 12 Volt - 100 Amp - Continuous Duty - Grounded
- Accessories and Parts
- Battery Boxes
- Switches and Solenoids
- 100 Amp
- Pollak
more information >
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