MPP Solar/Big Battery solar generator shut down

[Diemjoe]

Hi,
I built a solar generator with the MPP solar 2424, 2 12v Big battery and 2 Rich solar 200w panels. I put it together about a month ago and has been working to power my limited needs for 120v in my totally off grid trailer.
I did notice that it beeps at sundown. I thought it was just a warning that there was no more solar coming in.
This morning I noticed my phone plugged into a trailer outlet was not charging.
Checked the inverter and it would not power on. One of the Big batteries voltage display was off. The other display is showing 12.8. I checked the now not working battery and it was 12.9.
I cycled the power on the inverter to no affect. Same for the battery.
Any ideas? Am I missing a trip switch? The panels are in the sun 12 hrs a day.

Thanks

Don Miller

 

[Diemjoe]

Just an update. Further research via my limited internet service makes me think it is a Big battery problem. I don't believe that an LCD panel can't run on 12.9v but maybe the Inverter needs the full 24v system up to run. Have a nite out to big battery and MPP Solar. Figures thus happened on a weekend.

 

[Diemjoe]

Update number 2.
I just got off the phone with the shopsolarkits support. They confirmed my suspicion that the inverter needs both batteries running to work. Sounds like I can focus on Big Battery now.

 

[Diemjoe]

Update #3.
I spoke to both big battery and shop solar kits. It looks like the big battery's voltage dropped low enough that the MPP Solar couldn't power up. Big Battery said I should charge the Battery in question separately. I only had the series Anderson cable so they are kindly sending be a single. Will update after that arrives.
I am a little concerned at how far out if Sync these batteries became. Especially after only a month of very limited use.

 

[Diemjoe]

Another update. It seems that the batteries dropped below a voltage that the MPP Solar needs to run. Big Battery sent me a single Anderson cable that arrived today. I charged the battery on my generator for about 4 hours this afternoon. I took it off the generator at 13.2v and hooked it back into series. The MPP Solar fired right up.
I tweeked some settings on the Menu and will see how it works out.
BTW. The other battery was at 12.9 when I hooked the other to it in Series. Hopefully the .3v difference isn't too much out of balance.

 

[jasonhc73]

I have a very similar setup. But I have more solar pumping into the batteries.

What do you have for your cut-off voltage?
I use Solar Assistant.io now to configure my LV2424, sorry I don't know which "program number" this is on the LV2424.

Another Cargo Trailer setup.

This is now officially a legitimate sickness. My 4th off-grid system: The players: This setup is actually cheaper than going with a PWM Hybrid all in one unit 48V unit. I have AC input to charge the 48V batteries with shore power. (The 21.99 charger) A way more than I will use MPPT battery...

diysolarforum.com

 

[Diemjoe]

I woke up to a dead battery and MPP Solar again this morning. The only load on it was the the clock on the microwave. I spoke to Big Battery again today and it seems that this is a known problem and they no longer support 24v via 12v in Series. Their suggestion is to get a $200 charger for when the 2 get out of balance. :-(

 

[Diemjoe]

I have a very similar setup. But I have more solar pumping into the batteries.

What do you have for your cut-off voltage?
I use Solar Assistant.io now to configure my LV2424, sorry I don't know which "program number" this is on the LV2424.

Another Cargo Trailer setup.

This is now officially a legitimate sickness. My 4th off-grid system: The players: This setup is actually cheaper than going with a PWM Hybrid all in one unit 48V unit. I have AC input to charge the 48V batteries with shore power. (The 21.99 charger) A way more than I will use MPPT battery...

diysolarforum.com

View attachment 66050

I can't remember the settings at the moment and the MPP Solar display isn't working cause the batteries are too low. You would think that they would have an internal battery that works when the batteries aren't hooked up.