How to Power Two 12 Volt Trailer Batteries with 2012 GMC Sierra

Products Featured in This Question

Starter Solenoid - SPST - 12 Volt - 100 Amp - Continuous Duty - Grounded

(12)

$33.90

Bulldog Winch Rear Wiring Kit - Quick Connect to Terminal End - 3 Gauge - 24' Long

(9)

$257.99

Question:

Hello, I tow with a 2012 GMC 1500 6.2L. After reading how to set up and isolate my truck battery from the trailer batteries using: Battery Isolation Solenoid PK5231201 and DW05705-1, Fuse Tap Kit F2526, Pollak Pin Socket PK11851 and PK11852 with PK11771, 10 guage wire 10-1-1 and 4 guage battery cable, can you please clear up my confusion? Will my alternator keep three batteries charged? If not, should I install a second truck battery, and set it up for the starting battery? I do see any questions of setting up the TR118665 with two batteries. Thank you.

asked by: Danny M

Expert Reply:

The Solenoid # PK5231201 is designed to allow you to keep your trailer connected to your truck, with the truck's ignition off, without draining the truck's battery. It connects between the truck's battery and the 12 volt pin on the 7-way at the rear of your truck.

The alternator of your 2012 GMC 1500 supplies power to both batteries and maintains a charge. However, due to the distance needed to cover to get that much power back to your trailer you won't get enough power to charge them back to life if they're dead. No matter what gauge wire you're using. For a 3-gauge wire you could use Bulldog Winch Universal Wiring Kit # BDW20026 and you should use a circuit breaker to protect your truck's battery from shorts along the circuit.

expert reply by: Charles S