Charging Capacity of 12-Volt Circuit on Vehicle 7-Way Socket

Question:

Reno H advised that Since your truck has a 7-way connector, you could maintain the power to the battery but not charge it.inch If I connect the Red/ Black wire to a battery charge controller shouldnt I be able to charge my trailer battery? Question 2: if I have a charge controller connected to a solar panel, can I use the Purple backup wire to maintain charge on my car battery? assume the 16g wire is sufficient Thanks.

asked by: Brian D

Expert Reply:

The power delivered on the 12V circuit of a 7-way trailer connector is enough to maintain a charged battery while you travel down the road, but this circuit does not have enough juice to re-charge a battery that has been depleted from use. Depleted batteries need a shore-powered charger like one of the CTEK units, such as # CTEK56353.

Solar battery chargers like Performance Tool # PTW2997 can be used to provide a trickle charge to a battery mounted on a trailer but I do not recommend it for a vehicle battery since it will not charge it nearly as much as simply operating the vehicle will. The vehicle alternator will deliver far more charging current than a solar panel.

Wire of 10-gauge like # 10-1-1 is appropriate for a 12V circuit; 16-gauge is too light for this application.

expert reply by: Adam R