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E02 over-voltage error, same battery, different controllers

flammafeuer

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Joined
May 25, 2022
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My test setup is the following:
  • Panel
    • 1 x SanTan Solar 240 W panel: ~38 Voc, ~30 V for max current (Imax ~8 A)
  • Controller
    • Renogy Wanderer 10A (PWM)
    • HQST 40A (MPPT) (in photos; not using the Wanderer anymore)
  • Battery
    • Weize 50 Ah LFP (12.8 Vdc nominal, 14.4 charge voltage)
  • Cables
    • 10 AWG 10ft from panel to controller
    • 10 AWG 3ft from controller to battery
Things seem fine as the battery charges, on either controller. However, when the battery approaches being full, both of these controllers produce E02 errors, which seem to be over-voltage on/from the battery. The error is produced, a few seconds pass, and the controller tries again, producing another error. This is 100% repeatable. I believe I have set the controllers up correctly, simply setting for Li mode and updating the charge voltage to 14.4 Vdc. I've unplugged my test system when this has happened, because I don't know if I'm damaging the battery.
 

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Things seem fine as the battery charges, on either controller. However, when the battery approaches being full, both of these controllers produce E02 errors,
Using a ' SanTan Solar 240 W panel: ~38 Voc,' into a 12v through a pwm isn't right, even if 50Voc is in the specs.
What happens when the battery level is low the voltage through the pwm is relatively low as well. This rises along with the charge. When the battery is full there is nothing to bring the voltage down. A suitable load will help although getting the right panels with a lower Voc would also help but even these could eventually do the same, only takes longer and to a lower voltage which may not bring up a error code but still just as damaging.

The significance of this is overlooked. Lead Acid will gas and fail. Li will go boom!


I can not give a recommendation of a better CC as I have no personal experience of any that perform well under full charge/nil load conditions.

I convert all my high Voc panels to 12v and use load diversion to keep the voltage through my PWMs down. The most basic is a $5 XH-M609 low/high disconnect module with a 35v halogen light as pictured....been working well for the last few months with on at 14.5v and off at 13.3v



vhm009.jpg
 
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"both of these controllers produce E02 errors"
Something does not make sense because the HQST 40A (MPPT) is showing the same issue per OP.
 
"both of these controllers produce E02 errors"
Something does not make sense because the HQST 40A (MPPT) is showing the same issue per OP.
That's correct. I updated the original post; what is in the photos is the MPPT controller, and is what I am mainly trying to troubleshoot now.
 
That's correct. I updated the original post; what is in the photos is the MPPT controller, and is what I am mainly trying to troubleshoot now.
From the photos both controllers look like they are PWM. The HQST one may have a MPPT mechanism on top of the PWM to be able to call itself a MPP CC. Although the manual states it is negative grounded this doesn't rule out it not using the PWM circuit. The same problems and fixes may apply to both but this needs to be clarified.
 
From the photos both controllers look like they are PWM. The HQST one may have a MPPT mechanism on top of the PWM to be able to call itself a MPP CC. Although the manual states it is negative grounded this doesn't rule out it not using the PWM circuit. The same problems and fixes may apply to both but this needs to be clarified.
Both photos are for the HQST MPPT controller. I'm not sure how I'd prove that this is or isn't an MPPT controller, though. They have a video on Amazon showing data they says illustrates it is MPPT. Another user review says MPPT panel voltage was higher than the panel voltage, meaning it was MPPT (and I can confirm I see the same). If you have any suggestions on how I'd tell, please let me know.

What do you use to knock the voltage down to 12 V, before applying the disconnect?
 
'm not sure how I'd prove that this is or isn't an MPPT controller
It is a MPP controller. It is also a PWM CC with inbuilt MPPT which allows them to call it a MPP CC....this is my assumption only from the photos!

''What do you use to knock the voltage down to 12 V, before applying the disconnect?'' ....the diversion is after the pwm...I do have other disconnects on the PV/CC hv side but these seem too unreliable to recommend.

Rule number one - match your panels to your battery ....12v (Voc<22v)PV to 12v batteries, 24v(Voc<44v) to 24v batteries....google mppt graphs.

I convert my 'house' panels (see YT for info) to 12v because I have a 12v system and just use PWMs (22panels 5PWMs) but will still get over voltage (inverter<15V) unless there is a diversion load specially after light rain.

Edit...also post a photo of the wires into the CC to rule out other issues.
 
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  • Battery
    • Weize 50 Ah LFP (12.8 Vdc nominal, 14.4 charge voltage)

Sort of an old thread, but I found the BMS in the Weize battery I have to cut off charging at 14.0v. So when the Ronogy tries to charge it higher and the BMS opens, it sees an over voltage at the battery terminals and thus the E02. I had to set my controller to only charge to 13.8v to get around the issue with this battery. Just something to look at.
 
I have the same issue with Renogy Wanderer 10A (PWM) and an Aolithium 100AH LiFePO. Controller states E02 when battery is fully charged and panel is producing electricity. I have two of the controllers and both error. The only controller setting that can be changed is boost voltage (default 14.2, 12.6-16.0.) I tried all settings below the default with no change. Unfortunate as the controller otherwise has performed as it should.
 
HQST 60A here, 48v system voltage, 4 Weize 12.8V TPLI-12100AH in series. It's been a cool crisp day with not a cloud in the sky, and the controller is E02'ing every few moments. I turned on the inverter with a 500W load to calm things down but am now concerned.

The TPLI-12100AH case states...

Charge voltage: 14.4V (14.6V max)
Charge current: 100A max (I have yet to exceed 26A)
Std/Max Charge: 50A / 100A
Continuous/Peak discharge: 100A / 200A (3 seconds)
It allows up to 4 batteries in series.

Parameter settings (from ChargePro software)

System Voltage: 48V
Battery type: LI
Boost Charge Voltage: 57.2V
Over-discharge Recovery voltage: 50.4V
Over-discharge Voltage: 44V

If I unlock and put it on USE I have these options (and values assigned). I have not switched to these. Still on the above.

Equalize charge voltage: 57.2V
Boost Charge Voltage: 57.2V
Float Charge Voltage: 57.2V
Boost Charge Recovery Voltage: 50.4V
Over-discharge Recovery voltage: 50.4V
Over-discharge Voltage: 44V
Equalize charge time: 0 min
Boost charge time: 120 min
Equalize charge interval: 0 days

Suggestions besides putting an inverter load on it are welcome.
 
Boost Charge Voltage: 57.2V

This could be a bit high if your batteries are not balanced. One may be going into OV and tripping the BMS. That will cause the CC to see a higher voltage on it's output just long enough to throw a E02.
 
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