AnswerID: 666 Submitted: Friday, Jun 22, 2001 at 00:00
Jim Evans
replied:
Jonathan, another option is to (securely) mount a battery, preferably a sealed one, in the rear of your vehicle adjacent to the
fridge. The positive terminal would be connected to the existing vehicle battery by a reasonably heavy wire via an isolating solenoid. The negative side of the auxiliary battery would be connected directly to a suitable ground point on the vehicle body. The solenoid would be operated by the vehicle ignition so that the two batterys are in parallel when the ignition is on, and isolated when the ignition is off. Your
fridge and any other required
accessories could then be run from the auxiliary battery without fear of your main battery being flattened. I have run with this system for many years in a variety of vehicles and have had no problems. A flat auxiliary battery has no effect on the starting ability of your main battery even though they are in parallel when you are trying to start the vehicle as the discharge from the main to the aux is limited by the current carrying capacity of the connecting wire and is only for a very short period before the motor is started. Even on a diesel with preheating this has not been a problem.
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