breakaway battery

radioman · Dec 15, 2009

I have a 2 year old going on 3 years 16 ft landscape trailer with a breakaway system. It came with a dinky little battery in a tiny box. Last spring when I took the trailer out to get it road ready, I tested the breakaway and found the battery is dead. There is no charging wire to it. I took it out and tested the voltage and found it was low. I charged it with my regular car charger overnight and the next day it was 12 volts. All good ? I thought so. 2 days later I decided to check it out and sure enough it was dead again.

Being pressed for time and low on cash, I swapped the battery with the RV marine battery from my camper to the trailer and added a power wire to keep it topped off. It been fine ever since.

Now I am getting that nagging feeling again. Checking old battery I learned its a GEL battery. Did I ruin it with car charger? Am I supposed to have something to prevent rv battery from overcharging ? I don't see one on camper. I want to get it right this winter before I put it back on road in spring.

MFRED · Dec 15, 2009

All the trailers I've wired I've put in a seperate charger. They come from Tekonsha and use the trucks 12V power supply to keep the trailer charged. They're about $30 if I remember right. They also have kits with a battery, charger, breakaway switch & mount that are handy if you need more than one of the above. Usually cheaper as a set as well.

I've seen some cheaper trailers with just a diode hooked into the battery. I'm not sure wether it was fed when the brakes were actuated or what. Never really checked. Works, but doesn't seem like the best long term solution.

Diamondpilot · Dec 15, 2009

I have seen them with both a charge circuit and just a wire. Never seen a diode but it could not hurt. Most modern trucks use a relay in the truck to prevent the battery on a trailer from back feeding to the car when the alternator is not running.

I think your battery was just bad. They are only $20. Just pick up a new one and hook up a positive lead from your trailer plug to it. If you have the 7 round which is most common its the pin at the 1 o-clock position as shown in this picture.

Untitled

Here is the charge circuit from the same guy for only $10ish

Battery Charger- 12 volt Trailer Camper Break Away:eBay Motors (item 260436650098 end time Dec-23-09 20:34:17 PST)

Here is a the hole set up for $ 34ish

Trailer battery break away system, w/ CHARGER! New OEM:eBay Motors (item 370273360591 end time Jan-09-10 01:14:20 PST)

Chris

radioman · Dec 15, 2009

I'm thinking the same thing-bad battery. Who knows how long he had battery in the trailer before I got it. I just noticed that there was no charge on trailer when truck is hooked up and running, I know truck is fine cause I checked truck with camper and got charging voltage. I think I'll get the whole shebang from ebay you pointed out since its not that expensive, I just thought the battery will be over 30 bucks. Looks like I owe another one to TBN for better prices.

Diamondpilot · Dec 15, 2009

The guy on Ebay is Paul. He runs R@P Carriages. Great guy and his wife also. Give them a call. It will save you a few $$$ and he will make a little more off the deal since he will not have to pay Ebay. I buy most my stuff from him. A+ service and fair prices. Plus he will be there to answer any questions.

R and P Carriages Trailer Sales, Service, Parts and Rentals

Chris

Ken45101 · Dec 16, 2009

Some trailers are wired to charge the battery, others are not.

Even my dump trailer will not charge off of the truck

I brought one in a couple of years ago from the horse trailer to charge it. It's never made it back to the trailer

They really ought to charge automatically, IMO.

Ken

Diamondpilot · Dec 16, 2009

Just wire it up correctly and it will charge. I or any other tech familiar with trailer wiring could fix your problem in 10 minutes.

Chris

kennyd · Dec 16, 2009

Some are hooked up to the brake light circuit and are "supposed" to charge when the brake lights are on-Yeah right

But the trailer OEM's get away with it.

kennyd · Dec 16, 2009

Ken45101 said:
Some trailers are wired to charge the battery, others are not.

Even my dump trailer will not charge off of the truck

That is a simple fix, does your trailer plug have +12v to it when the truck is running?

Diamondpilot · Dec 16, 2009

kennyd said:
Some are hooked up to the brake light circuit and are "supposed" to charge when the brake lights are on-Yeah right But the trailer OEM's get away with it.

I have heard of some doing this but never seen that crap personally. In the 100 or so trailers I have worked on they are either wired properly or not at all.

Chris

radioman · Dec 16, 2009

ok , got two more questions. Is it ok to charge a gel type of battery from truck power ? reason I asked is that where I bought my trailer from, I had it inspected there and told him about dead battery and he said you can't charge a gel battery that was in there before. Other question is it really enough to charge a battery from the brake light ? I find it hard to beleive as some people like me don't brake excessively- I just drive defensively.

Diamondpilot · Dec 16, 2009

radioman said:
ok , got two more questions. Is it ok to charge a gel type of battery from truck power ? reason I asked is that where I bought my trailer from, I had it inspected there and told him about dead battery and he said you can't charge a gel battery that was in there before. Other question is it really enough to charge a battery from the brake light ? I find it hard to beleive as some people like me don't brake excessively- I just drive defensively.

Every brake-away box I have installed had a gel battery and it has charged with zero issues. My personal trailer has had the same battery for nearly 6 years now. I have never put it on a charger, it charges only from my truck. I went out and check the voltage and its right at 12volts and I have not used the trailer in over a month.

As for the brake light thing if it is done which I am sure some do this could cause issues. What if you had a shorted battery? Now it blows the fuse and you have no brake lights. Also if it was wired this way the 12 volts back feeding would illuminate the lights all the time, even if the trailer were not hitched up. A diode could solve this but why bother? Just wire it right from the start.

Remember the battery is most likely never used. Its only purpose is to supply the necessary voltage to the brakes for 15 minutes if the trailer becomes disconnected.

Chris

kennyd · Dec 16, 2009

radioman said:
Other question is it really enough to charge a battery from the brake light ? I find it hard to beleive as some people like me don't brake excessively- I just drive defensively.

No. It is just a way to be cheap...It is NOT a good idea at all. They should fail state inspection if wired that way IMO.

Soundguy · Dec 16, 2009

the break away kit on my big tex came with a SLA battery, and a small charge controller the size of a pack of matches. Battery dies after a couple months of non use, but tops back off fast when driving. As long as it has enough juice to engage the brakes and stop the trailer once it comes off.. it's done it's job.

soundguy

radioman said:
I have a 2 year old going on 3 years 16 ft landscape trailer with a breakaway system. It came with a dinky little battery in a tiny box. Last spring when I took the trailer out to get it road ready, I tested the breakaway and found the battery is dead. There is no charging wire to it. I took it out and tested the voltage and found it was low. I charged it with my regular car charger overnight and the next day it was 12 volts. All good ? I thought so. 2 days later I decided to check it out and sure enough it was dead again.
Being pressed for time and low on cash, I swapped the battery with the RV marine battery from my camper to the trailer and added a power wire to keep it topped off. It been fine ever since.

Now I am getting that nagging feeling again. Checking old battery I learned its a GEL battery. Did I ruin it with car charger? Am I supposed to have something to prevent rv battery from overcharging ? I don't see one on camper. I want to get it right this winter before I put it back on road in spring.

Newblue · Dec 17, 2009

Diamondpilot said:
I have heard of some doing this but never seen that crap personally. In the 100 or so trailers I have worked on they are either wired properly or not at all.

Chris

I had one that took me some time to figure out - The brake lights were tied into the brake wiring. So when the brakes were applied, the lights would vary their brightness depending on what voltage the brake controller was sending out. I kept searching for a bad ground but all the grounds were good. Traced the wires and found the connection. This was on an old 10 ton triaxle I had.

RavensRoost · Dec 17, 2009

A battery that has "rested" for 4 to 8 hrs and only has 12.0 volts is virtually a dead battery. A fully charged battery after same rest should be about 12.6 volts.

RavensRoost

Soundguy · Dec 17, 2009

yep.. at 12v, when at rest, the SOC is about 23.5%

soundguy

Soundguy · Dec 17, 2009

yep.. at 12v, when at rest, the SOC is about 23.5%

soundguy

radioman · Dec 17, 2009

kennyd said:
No. It is just a way to be cheap...It is NOT a good idea at all. They should fail state inspection if wired that way IMO.

kenny- I agree!

A battery that has "rested" for 4 to 8 hrs and only has 12.0 volts is virtually a dead battery. A fully charged battery after same rest should be about 12.6 volts.

RavensRoost

ravenroost and sound guy- thanks for the tidbit!

Beleiveme - the breakaway battery questions feels like a dumb one- but bugs me. I just gotta know for sure.

As for the brake light thing if it is done which I am sure some do this could cause issues. What if you had a shorted battery? Now it blows the fuse and you have no brake lights. Also if it was wired this way the 12 volts back feeding would illuminate the lights all the time, even if the trailer were not hitched up. A diode could solve this but why bother? Just wire it right from the start.

Thanks diamondpilot- thats what I suspected.

Diamondpilot · Dec 17, 2009

Newblue said:
I had one that took me some time to figure out - The brake lights were tied into the brake wiring. So when the brakes were applied, the lights would vary their brightness depending on what voltage the brake controller was sending out. I kept searching for a bad ground but all the grounds were good. Traced the wires and found the connection. This was on an old 10 ton triaxle I had.

Man you see everything on trailers. Every back yard shade tree mechanic thinks they can wire them. I have seen Romex used and even jumper cables.

Chris