Why Should You Disconnect The Battery When Flat Towing

Question

Question:

What is the purpose of disconnecting the battery?

asked by: Chris W

1

Helpful Expert Reply:

The general reason a battery needs to be disconnected for flat towing is because there are certain functions that need to be disabled to prevent your vehicle's battery from draining. You wouldn't want to get to your destination and unhook and then have a dead battery and not be able to move your vehicle. You should always follow your vehicle's manual to the letter to prevent damage to your vehicle.

If you want to install a switch to make disconnecting and reconnecting the battery simple you can install the Roadmaster Automatic Battery Disconnect with Switch for Towed Vehicle w/ Supplemental Braking System Item # RM-766.

Braking systems will connect to your battery and drain it so using a battery charger like the BrakeBuddy Towed Vehicle Battery Charge Kit Item # BB54FR will keep your battery topped off. If you purchase a Brake Buddy branded braking system it will come with the battery charger included.

If you need help picking out any other flat towing equipment then just reply back with the year/make/model of your vehicle.

expert reply by: Kevin C

1

Robert B.

9/1/2024

I plan on purchasing a 2025 trax and it requires the battery to be disconnected. Could you not use the battery charging lead to charge the car battery while going down the road

Kevin C.

9/2/2024

@RobertB You can still have a charge line # RM-156-25 running to the battery even though the battery is disconnected. The disconnect is just between the battery and the vehicle's systems. You'll still likely have your braking system wired directly to the battery, draining it as it activates. The charge line would also run directly between the battery and the 6-pole socket # PK12720.

Jim G.

10/20/2024

@KevinC The Trax Owners Manual says disconnect the positive cable which is a bear on the 2025 Trax. The negative cable is a piece of cake. Am I missing something or isn’t disconnecting the negative cable doing exactly the same thing? Jim

Kevin C.

10/21/2024

@JimG If you're going with a disconnect switch like the Roadmaster # RM-766 then you would have to go with the positive wire, but if you're just physically disconnecting the wire each time you flat tow you can just disconnect the negative cable.

See All (4) Replies to Robert B. ∨

Answer 1

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Answer 2

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Answer 3

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Answer 4

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Answer 5

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Answer 6

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Answer 7

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Answer 8

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Answer 9

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Answer 10

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Answer 11

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