Thor Vegas + Lithium Batteries + Shore Power-long term

[Lysergeon]

Hi all, I have recently installed, in my 2018 Thor Vegas 25.6, 2x100ah PowerRoad Lithium Batteries(with built in bluetooth monitoring), and a progressive Dynamics PD9180ALV converter.

This has all been working great off grid, but now I am on an RV pad for the winter with shore power, I am wondering if anyone else has been in this type of setup and what the best route is to maintain the health of the lithium batteries?

Should I disconnect them all together (I heard this can be hard on the converter as it's not intended to power the 12v items alone).

OR I can just shut the shore power off and use the batteries for a couple of days until they drain down (not ideal, as it limits me to using my inverter for 120, and cant use my oven etc) but, worth it to save the batteries...

Or... is there another solution that might work? Does anyone know for what length of time leaving LIPO4 batteries at full charge is harmful?

Thank you!

[DavidEM]

I have always read that for long term storage (and I don't know what that is) you get the best life out of LFP batteries by storing them at 75% or less.

And FWIW your converter will be fine powering your DC system with no batteries attached.


David

[Lysergeon]

Thanks David, yes I have heard the same... so maybe my best bet is to just disconnect them for the winter and leave at 75%?

[Projectman]

I have. 3 Battleborn battery bank and stored my Vegas for the winter. I disconnected them fully charged so they would have no charge or draw. Did fine in freezing New England winter. Stayed fully charged till the new season. Charging is not good for them in sub freezing weather and since I would start my engine and generator at least once a month, I didn’t want to involve them. I jumped the generator with another 12v that I had to start it.

[Lysergeon]

Right, but I will actually be in the unit for the winter, so will be using power.. I saw a similar question asked on the battleborn forum and their answer was

"If you are storing your rv and wish to have it plugged in, we would recommend a float voltage of 13.6 volts. If you have a higher voltage applied in float(such as 14.6) then we would recommend that this be no longer than 3 weeks at a time."

My batteries right now (connected to shore power) are sitting at 13.5v... so I am wondering if I am ok to just leave them? It does not get below -5C where I live so the cold charging thing doesn't really matter..

That's why I am wondering if anyone else has been in this particular situation and left them connected or no?

Thanks all

[Lysergeon]

I guess the other question I have is, can I just use the "use/store" switch in the vegas to disconnect them from the converter while on shore power? I really would like to leave the batteries connected, but from what I hear, even if you have it in "store" mode, the stereo drains power or something silly like that?

Is this not the purpose of that switch though? to disconnect the batteries? Will the shore power still work on this setting?

[bevedfelker]

The USE/STORE does not fully disconnect the house batteries. There is parasitic load that will drain down the batteries. The only way to ensure the batteries are fully disconnected is to put some kind of battery disconnect on the battery bank (like a knife switch) so that the batteries are physically disconnected not just electrically disconnected.

[Lysergeon]

Originally Posted by bevedfelker

The USE/STORE does not fully disconnect the house batteries. There is parasitic load that will drain down the batteries. The only way to ensure the batteries are fully disconnected is to put some kind of battery disconnect on the battery bank (like a knife switch) so that the batteries are physically disconnected not just electrically disconnected.

Ok thank you, hmm, are there any instructions around on how one would install such a switch? I am not great with these type of things, and where I am located not really any options for having it installed professionally..

[DavidEM]

The Axis' house batteries are easily accessible under the steps. It is easy enough to disconnect the black wire going to the negative battery terminal. It should be the only wire (except for the jumpers between the two batteries) that attaches to the negative terminal. That should completely isolate the house batteries. Since it takes about 30 seconds to do this, it doesn't seem worthwhile to install a separate switch to do the same thing.

The pic shows the black negative wire with an arrow pointing to it. Just unscrew the nut on the battery terminal and remove the wire.

David

[Travelin' Texans]

Originally Posted by DavidEM

I have always read that for long term storage (and I don't know what that is) you get the best life out of LFP batteries by storing them at 75% or less.

And FWIW your converter will be fine powering your DC system with no batteries attached.


David

You will however damage or overload the converter if attempting to power slides, levellers or any other high amp devices with the converter & no battery. Lights, fridge/water heater control boards or other low amp items should be fine with only the converter.