Input charge voltage getting stuck?

[turbineinfo]

My set up:
Three 200 watt Renogy panels in series
One Epever Tracer 4210AN charge controller with MT50 display unit
The Epever is set to the default LFP04 battery type
One Chins 200ah battery, 100 amp BMS
One Xantrex 2000 watt inverter
I live in Southern California and get a good 6 hours of sun in the summer

Observation:
At 12 noon, in full sun, the MT50 shows (what I understand) a 12.9 input voltage (see attachment)
In order to bump up the input voltage, I have to turn off my inverter, disconnect my solar panels from the charge controller, count to 20. Then I reconnect the solar panels to the controller.
I leave the charge controller turned off.
After these steps, the MT50 displays a input voltage of 14.6 (see attached).

It seems unnecessary to go through the above steps.
Can someone please explain what I am observing?
Am I resetting the battery BMS?
Is this typical behavior of Chins batteries? is this a common occurrence ?
Is there an glitch in how the charge controller interacts with the battery?

 

[sunshine_eggo]

12.5-12.9V on a LFP battery may indicate that charge protection or some sort of BMS dormancy is engaged.

An immediate jump to 14.6V is a concern as that may indicate a connection problem where your wiring resistance is too high.

Do you have the inverter connected to the load port of the MPPT?

Have you tried placing a significant load on the inverter to see if it "wakes" up the system?

 

[turbineinfo]

My inverter is connected directly to the battery terminals. The load port in the charge controller is currently unused.
The loads on the inverter are one to two TVs and sometimes a fan.
According to my Victron smart shunt, each TV draws about 7 amps (87 watts)
The issue described above was taking place before the smart shunt was installed.
Thanks for your help.

 

[CaliSunHarvester]

I used to have the same charge controller, the 4210. I don't know what the term "input voltage" means.

To me it seems that it's charging with 14.6V, and when you turn off the panels, it shows the resting voltage of the batteries, which appears to be 12.9V.

Note that in the photo with the 12.9V there is no charging going on, the charging would be indicated by the > symbol.


"I leave the charge controller turned off"

it should always be "on".

I suspect that you don't have the EPEver configured correctly. It's been 18 months since I last set mine up, so my memory is vague.
I suggest you check the settings, battery type and voltage are the first. There was even a user setting that allows you to set all kinds of voltages. It may be good to compare the various voltage levels of the charge controller with the battery manual's recommendations.

 

[sunshine_eggo]

My inverter is connected directly to the battery terminals. The load port in the charge controller is currently unused.

Just making sure.

The loads on the inverter are one to two TVs and sometimes a fan.
According to my Victron smart shunt, each TV draws about 7 amps (87 watts)
The issue described above was taking place before the smart shunt was installed.
Thanks for your help.

If 12.9V is a real voltage, then your battery is at a low state of charge.

For it to then immediately jump to 14.6V suggests that 1) you have a bad connection or 2) your BMS is reporting a false low voltage.

Some BMS exhibit this odd behavior if they go into a standby mode or enter charge protection mode. Given that you are seeing this at high noon, I'm wondering if your BMS is engaging charge protection, and then it allows you to restart. Do you ever observe a higher voltage than 12.9V, a drop to 12.9, your voodoo dance, and then it goes back to 14.6V?

Here's my suggestion:

13.8V boost
boost duration 120 minutes
13.5V float
13.3V boost reconnect

See if the above settings change the behavior.

 

[CaliSunHarvester]

If 12.9V is a real voltage, then your battery is at a low state of charge.

the 12.9V is when it's not charging. 1st photo shows 0 current. It may be the battery's resting voltage.

14.6V is input from charge controller to battery while charging. Current is shown. A little over 300W go into the controller / the battery bank.

 

[CaliSunHarvester]

I think the problem is easy.
You run 2 TVs and 1 fan which may be 2 x 87W + 80W = 260W

Your panels produce 350W based on your photo (62V @ 5.9A = 365W)
(14.6V @ 24A = 350W)

You consume 260W and put 90W in the battery.
After 6 hours that's 0.5kWh

You need more panels or turn off the TVs.

Be careful with that charge controller. Since you have the 4210, I think the max voltage is 100V
The xx15 models allow 150V. I too had the 100V limit.
The 40 in the model name indicates max 40A charge current.

I had a 2s4p setup with my 4210.
8 panels @ 260W.. about 2kW
My battery was 24V, so charging current was up to 40A.. 40A * 25V = 1000W max charge.

With a 12V system your limit is
40A * 14V = ~500W max charge.

 

[CaliSunHarvester]

I also wonder why 3 panels @200W deliver only 350W. Long wires? Bad connections? Bad angle? Shade? Dirty panels? All of it?
Should be over 500W at noon.