How to Fix a Drained Battery on Flat Towed Vehicle

Published 06/22/2022

Products Featured in This Question

Roadmaster Even Brake Portable Flat Tow Brake System - Proportional

(57)

$1930.00

Roadmaster Battery Charge Line Kit for Towed Vehicles

(1299)

$43.00

Roadmaster Battery Charge Line Kit for Motorhomes

(148)

$66.00

Question:

So Ive set my TOAD up with a Roadmaster Even Brake and of course it uses the Toad battery to run its compressor and ancillary parts. I havent done anything to charge the battery in the TOAD. In your real world experience, will it be necessary or does a brake system use a negligible amount of energy to run on a daily basis? I know theres variables, but on average, is running down the Toad battery a concern? The Even Brake manual says the unit will go into a battery saver mode, so theres that, too. The Toad is a FIAT 500 so no key in the ignition and no other drain on the battery other than the normal clock and radio stuff.

asked by: Stu G

Expert Reply:

As you stated, there are variables at play. Congested driving conditions result in greater application of brakes than driving across the interstate but still, that does not mean the brake system will be engaged each time you apply the brakes on the motorhome. The Even Brake allows you to fine-tune the braking sensitivity to fit your personal preference. By adjusting the sensitivity on the operating unit, you get to decide how intense the change in forward momentum must be for the electromagnetic valve to respond.

Because the braking system typically draws its power from the towed vehicle to activate, some will start the engine on their towed vehicle and idle for a period of time while they take a break every couple hundred miles. I suggest you use the system then decide what is best for you. However, because it is not that uncommon for vehicle batteries to be depleted when the vehicle is being flat towed, we have the solution of the Roadmaster Battery Charge Line Kit for Towed Vehicles, # RM-156-25. This allows up to 15 amps from your RV's battery to be used to maintain the charge of your towed car's battery while the car is being towed. The charge line connects to the 6-way or 7-way plug on your vehicle and requires separate charge line in RV.

I f you do not already have a hot lead on the RV side, we have the Roadmaster Battery Charge Line Kit for Motorhomes, # RM-156-75.

expert reply by: Michael R