How much battery to stop a runaway trailer?

[indybp57]

This is not really an RV or Forest River question, but since there is a wealth of wisdom and experience on this forum I thought I would take advantage of it. Our church has a 5000# cargo trailer with dual Dexter axles and brakes on every wheel. The battery that came with it for the break-away brake circuit is a cheap little 12v - 5.4ah gel cell. The trailer sits about 350 days out of the year. Obviously, the battery does not stay charged sitting there for that long, and when I do get around to charging it prior to a trip more often than not it won't hold a charge very long, and I don't really trust it to do it's job in an emergency. For the cost of this little gel-cel, I can buy a 200 cca garden tractor battery at Tractor Supply. I know it is complete overkill but if it's more robust and reliable and is probably cheaper, than why not? My question is, how much current does it really take to activate a trailer brake, and is there any reason this is a bad idea?

[OldCoot]

On our race car trailers we always used a car battery for the emergency brakes and didn't worry about it.

[Crusadernoob]

I would suggest a new battery the same as your daily driver would work, but I would tie it into your daily driver's electrical system so it will keep a charge, then just install it back to the trailer, or think about a battery maintainer, never tried one for that long of a period but I would do something instead of buying batteries all the time.

[RPAspey]

Our trailers at work sit idle for weeks/months at a time. The mechanics put the batteries in a box which have a solar maintainer built into the lid. You might be able to buy one of those and after replacing the battery, try it.

[youroo]

Originally Posted by indybp57

This is not really an RV or Forest River question, but since there is a wealth of wisdom and experience on this forum I thought I would take advantage of it. Our church has a 5000# cargo trailer with dual Dexter axles and brakes on every wheel. The battery that came with it for the break-away brake circuit is a cheap little 12v - 5.4ah gel cell. The trailer sits about 350 days out of the year. Obviously, the battery does not stay charged sitting there for that long, and when I do get around to charging it prior to a trip more often than not it won't hold a charge very long, and I don't really trust it to do it's job in an emergency. For the cost of this little gel-cel, I can buy a 200 cca garden tractor battery at Tractor Supply. I know it is complete overkill but if it's more robust and reliable and is probably cheaper, than why not? My question is, how much current does it really take to activate a trailer brake, and is there any reason this is a bad idea?

The way this trailer is being used,buy a New batt(Original size or larger) place it on a (Good battery tender) put it on the trailer (ONLY) when needed for travel,the rest of the Year have it back on the Tender! No more Dead Batt.
The way you are using it now requires changing or charging it anyway,and not a Strong batt.when done! Youroo!!

[indybp57]

Those are all great ideas, my problem is I don't always know when someone is going to decide to use the trailer on a whim and I wouldn't have a chance to get the battery in it. In fact it happened just the other day, and I had the old battery at home. I looked up the specs on the 12v/5.4ah battery and they claim the internal leakage is such that it would only need to be recharged every few months. Our trailer has the breakaway system from Curt that will charge the battery from the TV, so as long as the battery is viable then we should be OK. Odds are it would never come into play, and if it does the battery is rated to provide 16 amps max for 5 minutes to draw it down to 9v. I would think at max braking the trailer would come to a stop in a few seconds. The 7 inch brakes are spec'd to draw 2.5 - 3 amps per wheel.

[youroo]

I didn't know (Anyone) could use it,most trailers are secured from use. If it is that easy to get to I am surprised that you even have a Batt or entire trailer! Youroo!!

[indybp57]

Originally Posted by youroo

I didn't know (Anyone) could use it,most trailers are secured from use. If it is that easy to get to I am surprised that you even have a Batt or entire trailer! Youroo!!

Well, almost anyone. Shortly after we got it someone took a hammer to the coupler lock but was not able to break it. As an extra measure we sank a big logging chain into about 3' of concrete and padlock it to the tongue. We have had batteries stolen out of our bus and our wdh coupler and torsion bars stolen out of the trailer. Anything is fair game anymore.

[Evereddie]

Fresh battery and a solar panel charger?