breakaway battery

[radioman]

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]

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]

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]

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

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]

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]

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]

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

soundguy

 

[Soundguy]

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

soundguy

 

[radioman]

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]

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