This thread has been helpful. I'm having a similar issue. System is a conext SW 4024, four 12v Kilovault AGM batteries - 2 series in parallel for 24v. Total 360 Ah. Midnite Classic 150 with 6 Q cells- total of about 2500 watts solar at 48v.
New system installed June of this year.
Everything was great until the short cloudy days set it. I did my best from the manuals to set the conext charger to all the right settings. Fired up the generator and had 29 volts at the SCP readout. That didn't seem right. Checked the voltage at the conext battery terminals and at the batteries themselves - both locations at about 28 volts (analog volt meter).
Using a 4.5Kw running watt generator.
After two weeks, four different tech support with two different companies, I finally got my hands on the Kilovault/Context Integration Guide. Corrected a few settings and things got a lot better.
What does not seem right is that despite the level of solar during the day, I'm down to 50% DOD on the batteries by 8 pm (sunset here around 5 pm). This is with less that 400 watts of load, typically. A 10 cu ft refrigerator set to warm, laptop, computer speakers and a few LED lights.
During my several weeks of trial and error getting the AC charging figured out, I had maybe 3 or 4 two hour charge sessions where the readout said 29 volts. Not wanting to do more, I had one morning where the batteries went to 40% and another where they went to 30%. Solar charging brought them back each day, I've been running periodic equalization sessions of 90 minutes each on solar, particularly after those low DOD nights.
Based on the advice above, I set my rate of charge on the conext to 29% and ran a 2.5 hour charge session this morning (heavy cloud cover) until the solar was able to take over, so the batteries got a fair amount (but not great) of Bulk and Absorption today. I get about 30 minutes of Bulk and the Absorption. Still down to 50% by 8 pm with minimal load. This doesn't seem right.
I checked the voltage at each battery as suggested above and I have the same reading at each battery: 13v during Absorption stage on AC (again, not precise due to analog meter).
Is there something different I can do to rebuild the batteries? Is it possible they will heal over time with proper charging from here on out?
One more note - I installed a Primus Air 40 wind turbine a month ago and it charges at Bulk rate when there is wind until the batteries reach max charge of 28.2v. On those nights when there is sufficient wind it can keep the batteries up in the 60% to 80% range.
Thanks
There is no such thing as a free education.