Batteries from 100 to 0

[DaveT]

I have converted to two 6v Costco Interstate golf cart batteries. We went camping last weekend, came back Tuesday. I was lazy and didn't unhitch till Thursday. No problems running the powered tongue jack.


Yesterday I went out to the trailer for some cleanup and the batteries are dead, dead, dead. Checked voltage at each and they are below 1V.


Batteries are 4 years old so, while I hoped for longer life, it's not the worst story about battery life I've heard.


I'm just curious about them both dying so fast and at the same time. I have 200w solar that keeps things charged.


Thoughts?


DT

[RPR]

I would do some trouble shooting to see what drained them down that far. Tongue jack working and now 1 volt. Drain somewhere. I would disconnect them and put a trickle charger on them. It may take several hours for the voltage to come up from one volt. Do not try and fast charge them at that voltage. Do more harm than good.

[GHen]

Certainly seems like there is more to be discovered to explain the problem.

200watts of solar could not keep up with the draw on the batteries? Were the panels covered by snow or storage roof?

Batteries generally go bad only one cell at a time, even if there was one dead cell in each battery, they should be at 9-10volts.

A furnace being on could not drain to 1 volt, they can’t even start under 10v. LED Lights on could not draw that much that quickly. A cheap inverter powering a fridge might be able to pull it that low.

My only guess is the trailer brakes were on, was the pin pulled on the emergency release?

I have a couple of the Costco 6v, being true deep cycles you should be able to bring the back to life. Golf carts are very hard on batteries and these work fine.
Mine have never been below 11.75 so I really don’t know how resilient they are to coming back from the dead.

[Vicr]

You have probably been killing your batteries for years. Do some research on battery care.

[CAG]

You don't say what state you are in but batteries here (Arizona) do not make it much more that 18-24 months. The Costco golf cart batteries on the RV would do a little better but the best I ever did with a pair was about 48 months.

[JohnWedell]

Have you checked the water level

[RAurand]

Wow and I just replaced a 12 volt battery on my trailer that has been working since 2014 (7 years) with 2 12 volt group 24 batteries.

[RPR]

Arizona heat is rough on everything. Older brother lives in Phoenix. I would melt during some months. Poor battery gets hot and no where for its heat to go!��

[Joey55]

I agree with John Wedell, but make sure you use distilled water to bring the level up to the proper mark. No water won't hold a charge no matter what you put on it.

[bap]

Check the water level, then disconnect both batteries from the camper and each other. Charge them up fully. Then put a load tester like this on each one. http://www.harborfreight.com/100a-61...ter-61747.html
That will tell you about the battery health. If they each check out ok then slowly start adding back power connections until you find the one that is draining the battery down.

[DaveT]

Originally Posted by GHen

200watts of solar could not keep up with the draw on the batteries? Were the panels covered by snow or storage roof?


<snip>


My only guess is the trailer brakes were on, was the pin pulled on the emergency release?

No issues with solar. Trailer brakes is a good tip; will check.

[DaveT]

Batteries are out of the trailer and each on its own charger right now.



Also, the batteries are taken out and stored inside garage at end of each season and regularly put on charger.


DT

[GHen]

Keeping them in the garage over the winter indicates you are not a newbie with batteries. You’ll find the problem.

I suggest you install a full battery disconnect on the negative side of your batteries until you get this figured out, well, you should have one even if the system is working perfectly. Only have the batteries ON when using the trailer.
A good car mechanic or electrician can use their meters to see where the draw is. Something is turning on.

You’re solar should keep the batteries fully charged even on cloudy days, if nothing big is turning ON, small stuff is always ON giving you parasitic drain. They would never allow the batteries to get to 1volt.
Good luck!

[DaveT]

Originally Posted by GHen

Keeping them in the garage over the winter indicates you are not a newbie with batteries. You’ll find the problem.

I suggest you install a full battery disconnect on the negative side of your batteries until you get this figured out, well, you should have one even if the system is working perfectly. Only have the batteries ON when using the trailer.
A good car mechanic or electrician can use their meters to see where the draw is. Something is turning on.

You’re solar should keep the batteries fully charged even on cloudy days, if nothing big is turning ON, small stuff is always ON giving you parasitic drain. They would never allow the batteries to get to 1volt.
Good luck!

Thank you. I have a disconnect for the batteries and also to isolate the battery-to-solar_controller and solar_panels-to-solar_controller (3 total switches.)


Historically, I've left everything "on" even when not camping.

[Cavie]

closet light left on? Storage light left on??

[GHen]

Hopefully the battery disconnect is not the factory disconnect. They generally leave too much stuff on, like smoke detectors etc... I never use our Factory disconnect, but use the full disconnect I installed all the time.

With all your solar wiring, do you have a shunt installed with a battery monitor like the ones made by Victron? My son has one and they are amazing. It will certainly help in diagnosing the problem.

[DaveT]

Left the batteries on the chargers for a few days; then took them off and let them just sit for a few. This morning both were at 6.2V/6.17V so seems nominal. Water level is good.


Re-installed them and hooked everything up. I do have a cheap bluetooth battery monitor on them and all looked good. Flipped the isolation switch (one that I installed, not factory ) and saw the voltage start to drop; more than I think it should. I messed about in the camper checking all switches but found nothing obvious.

Solar is still disconnected for now.

Hint's on troubleshooting? Current plan is a fuse by fuse check for current draw.

[RPR]

I use a clamp on amp meter as one of my tools to check for current draw along with my multimeter. It may not show the exact amp draw its near enough.

[Dobbs]

The fuse by fuse is a good start.
I read somewhere if you have a digital meter to set it to read amperage. Be sure to plug the cables into the correct spots. Remove a fuse and using the probes touch one to one leg where the fuse came out and the other probe to the second side. Read the meter and it will show how much is going through that circuit. Don't worry about doing it 'backwards'. The display will just show negative. Doing it this way you won't have to keep running out to the battery.

[DaveT]

First prize goes to GHen! The trailer brake pin was pulled. Was sure I had already checked that. Maybe it was "out" far enough to trip the circuit and then fell out.

I just pushed it back in is there anything more to it than that?

Thanks for all the tips.

D