Batteries losing charge while in storage

[tvfrfireman]

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

[Almot]

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.

[tenbear]

Time to invest in a clamp-on ammeter and see what the drain is.

[mena661]

tvfrfireman wrote:
I am losing about 15% of my charge every week and the batteries are a year old.

Sounds like you have a significant parasitic load on your batteries or like someone else mentioned, your batteries are shot. Remove the batteries from the RV and FULLY charge them separately with a portable charger (probably will take a few days), then let them sit overnight with NOTHING connected, measure the voltage afterwards.

[tvfrfireman]

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.

[Shadow_Catcher]

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.

[pugslyyy]

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.

[time2roll]

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.

[ktmrfs]

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.