My four six volt AGM batteries are losing there charge while the trailer is parked in storage. I disconnected all the wires from the positive terminal but still find them slowly discharging. In a second compartment I have to more batteries and noticed a wire from the positive terminal that goes directly to the hydraulic pump that is used in the level up system. Could this be draining the batteries? I have the trailer up on all 6 jacks to unweight the tires while it is not in use and am wondering if I should disconnect this wire from my battery. I have a 12 volt disconnect switch but it is down stream from t his hydraulic pump. Thanks for any tips....David

Batteries will self discharge even when nothing is connected to the terminals. How fast is determined by the battery type, outside conditions and a few other things. Or the batteries could be just failing.so.... how far discharged do they get, and how long does it take them to get that discharged.

If the pump has a direct switch it will not be draining the batteries. If it has an electronic control or relay then anything is possible.Otherwise AGM will still self discharge 1% or 2% per month. I suspect the battery may not be fully charged. The surface charge may give an illusion of full charge. Really needs to be held close to 14.5 volts until current drops to about 1/2 amp or less.Another alternative is to add 60 to 120 watts of solar and a good controller.

As above, are you fully charged above? Is your charge controller set up correctly for AGM batteries?I leave mine plugged in when not using it, plenty of storage places allows you to leave a battery tender hooked up.

AGM batteries should be able to go months in storage with out recharging (one of the reasons I chose them), as long as there are no parasite loads. Disconnect the negative terminal rather than the positive as there is less chance of shorting to the chaise. One bad battery will draw down the others in a bank.

smkettner wrote:If the pump has a direct switch it will not be draining the batteries. If it has an electronic control or relay then anything is possible.Otherwise AGM will still self discharge 1% or 2% per month. I suspect the battery may not be fully charged. The surface charge may give an illusion of full charge. Really needs to be held close to 14.5 volts until current drops to about 1/2 amp or less.Another alternative is to add 60 to 120 watts of solar and a good controller. Thanks for your response. I have 600 watts of solar but am under a roof. I am losing about 15% of my charge every week and the batteries are a year old.

Batteries losing charge while in storage | Good Sam Community

mena661
Explorer
Oct 28, 2013
RJsfishin wrote:
I wonder how many times they were run stone dead, and for how long ??
X2
RJsfishin
Explorer
Oct 28, 2013
Quote:

My four six volt AGM batteries are losing there charge while the trailer is parked in storage. I disconnected all the wires from the positive terminal but still find them slowly discharging.
------------------------------------------------

What part of this are some not understanding ?
Even w/ not being fully charged, there is something wrong w/ the batteries ?? I wonder how many times they were run stone dead, and for how long ??
MNtundraRet
Navigator
Oct 28, 2013
The solar panels, if properly installed, should have blocking diodes to keep the batteries from discharging back through the panels when sun cannot reach them.

One, or more. of the panels may be the culprit.
tvfrfireman
Explorer
Oct 28, 2013
smkettner wrote:
Spark = something is on. Just a matter of discovery.
The 12 volt switch that supposedly turns off all the power was in the off position. This is a new trailer (1 year old) and am mystified by all this. It has been in the shop almost four months in our first year of ownership. I am having trouble finding competent people to work on it. I could go on for pages with all the stories and will stop here. I can build a house from the ground up but electrical and especially 12 volt I don't have a clue. Maybe I should take it to an auto electric shop as the RV folks damage the outside of our new trailer every time we take it in.
time2roll
Nomad
Oct 28, 2013
Spark = something is on. Just a matter of discovery.
tvfrfireman
Explorer
Oct 28, 2013
smkettner wrote:
Yes something is draining them or one is bad pulling down the rest.
Full 100% charge and then fully disconnect and separate for testing.
Should hold 12.8+ volts for at least a few weeks.
I read the state of charge three days ago and it was 12.8 and is now 12.3. When I disconnected the negative cables, one threw a pretty good spark. This is with everything off.
time2roll
Nomad
Oct 27, 2013
Yes something is draining them or one is bad pulling down the rest.
Full 100% charge and then fully disconnect and separate for testing.
Should hold 12.8+ volts for at least a few weeks.
tenbear
Explorer
Oct 27, 2013
tvfrfireman wrote:
tenbear wrote:
Time to invest in a clamp-on ammeter and see what the drain is.
I will check into this tool. I am pretty sure that the drain must be the hydraulic system as one other person with same brand has the same problem on the DRV forum. The only thing hooked to the battery is the hydraulic system. I don't understand why so many things are wired upstream of the 12 volt cut off switch.. Thanks for you response..

I should have mentioned, be sure you get one that measures DC current. Less expensive ones may only measure AC current.
tvfrfireman
Explorer
Oct 27, 2013
tenbear wrote:
Time to invest in a clamp-on ammeter and see what the drain is.
I will check into this tool. I am pretty sure that the drain must be the hydraulic system as one other person with same brand has the same problem on the DRV forum. The only thing hooked to the battery is the hydraulic system. I don't understand why so many things are wired upstream of the 12 volt cut off switch.. Thanks for you response..
Almot
Explorer III
Oct 27, 2013
tvfrfireman wrote:
I am losing about 15% of my charge every week and the batteries are a year old.

New AGM can still lose 5% a month when average monthly temps are in mid-upper 80s, this is normal. The hotter it is, the faster they self-discharge. Check the manual, there should be a graph of self-discharge VS temperature. 15% seems a bit high for almost new AGM.

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