Battery charger needed for AGM's?

[drjjj]

Upgraded our battery bank a while back in our 2007 3400RL. Now have two 12 volt AGM's in parallel. When storing rig, how long can we store it (with battery disconnect on, of course) without worrying about hurting the batteries?

[scottz]

I had twin AGM's in my previous trailer (8 years old and still good) and have three in my current unit. I have solar panels so mine are always on charge, but they should hold a charge for a long time. As long as you disconnect them.

[Carl n Susan]

Originally Posted by drjjj

<snip>...When storing rig, how long can we store it (with battery disconnect on, of course) without worrying about hurting the batteries?...
</snip>

As scottz said, you need to disconnect the batteries at the batteries. The disconnect switch does not eliminate all of the parasitic power users (propane detector, Level-Up brain, etc,). They will drain your battery in a few weeks unless you disconnect the batteries completely.

[Phil P]

Hi

A solar battery charging panel is quite inexpensive and easy to hook up. I am fortunate that I can park ours at home and it has never been without power either 50 amp ac or 12V from the TV sense we purchased.

Phil P

[Twopetes]

This option will not be available if you are far from any 110 vac power, but I use a battery float system from Harbor Freight. Cheap and I do not worry about running the inverter or over-charging.


But I also pull the batteries since I live in Wis and have them in the garage. Still cold but not below freezing.


I like the solar idea

[rslopez65]

Originally Posted by carl n susan

As scottz said, you need to disconnect the batteries at the batteries. The disconnect switch does not eliminate all of the parasitic power users (propane detector, Level-Up brain, etc,). They will drain your battery in a few weeks unless you disconnect the batteries completely.

I have read this statement many times on this forum and I just don't understand how a battery that is disconnected using the switch can still power anything in the RV. It just seems to me that if it is off, it is off. You can even hear the propane detectors, etc. whine when the battery power is disconnected. The battery will drain on its own over time when disconnected but this isn't caused by parasitic power drain. Am I missing something?

[Lenny K]

Your rig is definitely wired different from others Ray. On our Montana and all other 5th wheels we've owned the cutoff switch does not cut everything off as the switch is not right at the battery but further along so it cuts off the 12V power distribution panel only. The items that draw power constantly like the propane connector are not connected to the power panel but draw their power from the batteries before the cutoff switch. This is done for safety reasons.
Therefore if your cutoff switch is not located right at the positive cable leading directly from your battery all power to your rig is not being turned off.

[scottz]

Lenny is correct. My batteries have 2 fuse holders connected directly to the batteries; yours is probably the same. The battery disconnect is downstream from these so does not cut them out. One of them powers the shore power cord reel, I have not figured out what the other one is for yet. Ray is also correct concerning the propane detector; at least on my 2017 Montana; it gets power from the DC distribution power and cuts out with the battery disconnect switch but there are definitely some loads that do not go through the disconnect switch.

If the RV is parked outside, a battery tender solar panel is a good option.

[rslopez65]

Guess I will remain confused. We had a disconnect system in our last 5er and it turned everything off on both batteries. We don't have a shore power cord reel to worry about and the propane is turned off for storage (I did think that the propane connector was controlled by pressure and not power anyway). Our batteries are located right next to the basement opening so not that far away. We have found our AGMs usually would last a month or more without charging so we will keep a close eye on the system now to see how it goes. Thanks for your help.

[scottz]

That is possible Ray. On my last 5th wheel, I installed disconnect because it did not come with one and when I was done it disconnected all loads. But that is not the way the factory does it. They connect some loads directly to the battery. I don't know why (the shore power reel is certainly not a safety issue) but they do.

It would be nice of Keystone provided electrical and plumbing drawings, but they don't.

Here is a photo of the fuses on my unit that do not disconnect with the main battery switch.

[rslopez65]

Scott, thanks for the photos. Now I can see what you all are referring to. Really appreciate your taking the time to help me get my mind around this one.

[Lenny K]

Oops that was supposed to be propane detector not propane connector. I am changing that in my post.

[Lenny K]

I guess I'm not going to change my original post as edit appears not to be available once another post has been made. Didn't realize that.

[rslopez65]

Originally Posted by Lenny K

I guess I'm not going to change my original post as edit appears not to be available once another post has been made. Didn't realize that.

That's OK Lenny, my brain has finally made the change. I should have realized that anyway. Getting old is so much fun.