Will Flat Towed Vehicle Charge Line Kit Prevent Back-Feed and Overcharging?

Question:

on your kit I do not see anything the isolates the toad battery from the coach battery. so I have two questions is there anyway from keeping the coach battery from over charging the battery in the towed car. and is there anyway to prevent the towed battery from feeding the 12 volts back to the coach battery.

asked by: Raymond Q

Expert Reply:

The Roadmaster Battery Charge Line Kit for Towed Vehicles # RM-156-25 has a circuit breaker to help isolate that circuit from issues, but it will not prevent back-feeding. If you want to prevent back-feeding which isn't typically an issue, you can use the Roadmaster Single Park Light Diode # RM-690. Because you are sharing power between two batteries at a low amperage there is very little risk of a surge issue. Another option is to use the Battery Isolation Solenoid # PK5231201 which will prevent power transfer between batteries unless the accessory post (connected to ignition) is activated.

Most systems will only allow a few amps of power that aren't being used by the towing vehicle to be transferred to the toad battery. This is really a maintenance charge which would not cause any overcharging or back-feed as the toad will also use battery power for lights or supplemental braking.

expert reply by: Jason S