Way to Charge Trailer Battery that Provides More than Maintenance Charge

Question:

I have a 2003 Chevy Tahoe with a 5.3 liter V8 and 4-wheel drive and a tow package. We are purchasing a small Casita trailer which has a single 12 volt battery to run various items such as LED lights, refrigerator sometimes, TV sometimes, etc. If I purchase an isolator such as PK5231201, will it be of sufficient capacity to handle the job or do I need to purchase one that can handle more amperage to keep the trailer battery fully charged? If I upgrade to two batteries on the trailer, will I need to get a larger alternator for the Tahoe and at what point would I need to get an isolator that can handle more amperage? Maybe it would be better just to get a larger capacity isolator to begin with in the event of a later switch to two trailer batteries. How do I decide what amperage it needs to handle? Also, how do I know that the wiring back to the trailer from the 7-wire connector is of sufficient size to handle the load? Is there anything else that I need to consider? Thanks for any guidance you can give on this.

asked by: Bob K

Expert Reply:

The Isolation Solenoid part # PK5231201 has an 100 amp rating which is pretty high. This would be more than enough for the 12 volt circuit of your 7-way feeding a battery on your trailer. Typically this circuit is rated at 40 amps or less. This method will provide a maintenance charge on your battery but would not charge a dead battery.

Most likely it's not the alternator that would need to be increased to get more charge on your trailer's batteries. The limiting factor is going to be the wiring of your vehicle back to the trailer connector.

The best way to charge the battery will be with a # BDW20207. Connect the ring terminal to the alternator post and then use the quick disconnect to attach to the other end of the wiring on your trailer battery.

expert reply by: Jameson C