Breakaway battery dead, or breakaway brakes not holding

If the breakaway battery is dead or the brakes do not grab when the pin is pulled, your trailer has no brakes if it ever comes off the ball. The fix is usually a new battery, a new switch or a charging fault, and a breakaway switch or kit installed typically runs $100 to $250. Florida requires breakaway brakes on any trailer over 3,000 lb gross that stay applied for at least 15 minutes.

Check this first

1. Find the battery box, usually on the tongue. Is the battery there, and are the terminals clean and tight?
2. Check the charge. Many boxes have a test button and light. A battery that will not light the test, or reads under 12 volts on a meter, is not ready. Dexter’s troubleshooting for its electric-over-hydraulic units says breakaway voltage should be at least 12 volts.
3. Look at the switch and cable. Is the cable frayed, the pin missing, or the switch cracked?
4. Pull the pin and test. Sundowner’s manual: pull the pin and test tow at under 5 mph; you should feel the trailer resist. Replace the pin immediately after, because the battery drains fast with the pin out.
5. Think about charging. If the battery is dead every time the trailer has sat, either it is not being charged from the tow vehicle or it is simply old.

What is usually wrong

Full ranges are on the pricing page.

Why it happens

A breakaway battery is small, and it drains while the trailer sits. Dexter’s storage advice is to remove the breakaway battery and store it inside, out of the weather, and charge it at least every 90 days. A horse trailer that sat through the summer in the pasture is the textbook case. Dexter’s and Featherlite’s maintenance schedules both put the breakaway battery and switch on the check-every-use list.

Why it matters

Florida’s s. 316.261(4) exists for the one moment you hope never comes: the coupler lets go. A charged battery and a working switch are what stop the trailer. Sundowner adds a warning worth repeating: the breakaway is not a parking brake. Chock the wheels when you unhitch.

When to call

If the battery is new and charged and the brakes still do not apply on the pin pull, the fault is in the switch, the wiring or the brakes. See trailer brake repair and trailer wiring and lights. Also check the coupler and chains, which are the first line of defense.