Howdy folks,
I have had my system installed in my motorhome for about a year and a half now and have had no issues, it's worked great, until last week.
The longest I had gone with out shore power was about 6 days (shortly after installing the system). Last week I went 8 days, and didn't quite make it.
Quick review of my system, 16x 271ah LiFeP04 batteries arranged in 2 banks of 8S2P to give me 24 volts and 542Ah. Victron Multiplus 24/3000/70 inverter, 1000W of solar fed via EPEver MPPT. My BMS are 200a Daly (came with the batteries), no Bluetooth or other means of monitoring the BMS. I do have a Victron 500A smart shunt that I use for my primary monitor.
On day 6 of my last off grid experience I had an inverter shut down. The shunt showed I was at 76% capacity. I started my generator and charged for a couple hours (it was nice to run the AC as well, was over 100 degrees where I was). Solar was spotty due to shade and weather, I was avoiding 110+ degree heat so mostly in the shade, but with clear skies was getting a good charge rates. However, thunderstorms arrived and cloud cover eliminated my solar window. I wasn't worried about it as I had plenty of battery left, or so I thought.
So here is the meat of my post, after getting home I started digging into my inverter settings and realized I was not fully charging my battery, I had absorption shutting off at 26.4 volts. Changed that to 29.2 and my inverter took all day to top off the batteries. This morning I checked cell voltages and things are not as balanced as I would expect.
Highest voltage in bank 1 is 3.596 and lowest is 3.339 Bank 2 is 3.545 a nd 3.342.
Do I need to re-balance my cells?
Should I replace my BMS with something I can monitor? I can only trust that they are working correctly. I am considering the Overkill Solar BMS.
Thanks in advance for all productive comments,
Andy
If case you are curious here are my cell voltages this morning:
I have had my system installed in my motorhome for about a year and a half now and have had no issues, it's worked great, until last week.
The longest I had gone with out shore power was about 6 days (shortly after installing the system). Last week I went 8 days, and didn't quite make it.
Quick review of my system, 16x 271ah LiFeP04 batteries arranged in 2 banks of 8S2P to give me 24 volts and 542Ah. Victron Multiplus 24/3000/70 inverter, 1000W of solar fed via EPEver MPPT. My BMS are 200a Daly (came with the batteries), no Bluetooth or other means of monitoring the BMS. I do have a Victron 500A smart shunt that I use for my primary monitor.
On day 6 of my last off grid experience I had an inverter shut down. The shunt showed I was at 76% capacity. I started my generator and charged for a couple hours (it was nice to run the AC as well, was over 100 degrees where I was). Solar was spotty due to shade and weather, I was avoiding 110+ degree heat so mostly in the shade, but with clear skies was getting a good charge rates. However, thunderstorms arrived and cloud cover eliminated my solar window. I wasn't worried about it as I had plenty of battery left, or so I thought.
So here is the meat of my post, after getting home I started digging into my inverter settings and realized I was not fully charging my battery, I had absorption shutting off at 26.4 volts. Changed that to 29.2 and my inverter took all day to top off the batteries. This morning I checked cell voltages and things are not as balanced as I would expect.
Highest voltage in bank 1 is 3.596 and lowest is 3.339 Bank 2 is 3.545 a nd 3.342.
Do I need to re-balance my cells?
Should I replace my BMS with something I can monitor? I can only trust that they are working correctly. I am considering the Overkill Solar BMS.
Thanks in advance for all productive comments,
Andy
If case you are curious here are my cell voltages this morning:
Bank 1 | Bank 2 |
3.341 | 3.469 |
3.339 | 3.342 |
3.454 | 3.545 |
3.493 | 3.538 |
3.509 | 3.511 |
3.519 | 3.509 |
3.508 | 3.487 |
3.596 | 3.382 |