EG4 battery keeps going into COV Protection mode

[paticus]

I have a 12v EG4 400ah rack battery that keeps going into COV Protection mode.

I have 2 other EG4’s with no problem. They are wired in parallel. It seems to happen when I charge them to 100%. It triggers around 13.7 volts

I’m not even sure what this mode means. And it seems suspicious that only 1/3 batteries goes into this mode. Attached are some pictures of the setup and my settings. Any ideas?

Btw restarting the BMS seems to get it out of this state, until the next full charge.

 

[sunshine_eggo]

The 3rd battery is imbalanced per your screencap here:



Nearly a 0.3V difference. That 4th cell is going over limit, so it's cutting charge to that battery (Cell Over Voltage).

Very common for new batteries of all brands and configurations. This should improve with time and cycles.

 

[42OhmsPA]

Reducing your absorption to 13.9V will help, if the cell Eggo mentioned still runs reduce the voltage further.

 

[jarred125]

I updated the firmware on my lifepower4 48V batteries and it’s been a total fiasco. I’m getting cell and module OV protection on all 6 batteries when fully charging.

 

[42OhmsPA]

I updated the firmware on my lifepower4 48V batteries and it’s been a total fiasco. I’m getting cell and module OV protection on all 6 batteries when fully charging.

This is why I run open loop and avoid firmware updates at all costs.
Maybe EG4 can send you the old firmware if you email them?

 

[paticus]

Thanks for the insight everybody, I’ll reduce the absorption voltage to 3.9 and see if that helps get things balanced.

 

[sunshine_eggo]

I would have suggested that, but it's triggering at below 13.8V, which is my go-to for slow charge and balancing joy.

I guess it's still worth trying, and I'd raise float from 13.5 to 13.6V

 

[paticus]

I would rather be conservative and not trigger COV mode, because I am not at the boat to reset it. So would you suggest 13.6 absorption and float =?.

 

[hwy17]

I would rather be conservative and not trigger COV mode, because I am not at the boat to reset it. So would you suggest 13.6 absorption and float =?.

Yes, if it is triggering at 13.7 then setting bulk absorb and float all to 13.6 will likely get the high cell group into balancing territory, then it could be held at 13.6 for a long time to balance, and then after some balancing it should eventually be able to go to 13.7 and hold there for more balancing, and maybe 13.75 after that.

It's possible even 13.5 would get the high cell into balancing at first, you can charge to 13.5 and then look in the app to see if it's balancing.

 

[paticus]

What should I set my float to if I do 13.5 or 13.6 absorption?

 

[sunshine_eggo]

What should I set my float to if I do 13.5 or 13.6 absorption?

0.01V below it

 

[hwy17]

Or the same 13.5 absorb and 13.5 float, so that it holds there. If the charger requires a lower float then as above.

 

[Spd_Rcr]

@paticus How old is your EG4 that goes into COV mode?

I have an issue with my new EG4 WP 12V 100Ah going into COV mode under similar conditions (near 100% charge and 13.8VDC).
Disconnecting the battery and letting it discharge a minute (small 5-10A load) gets it out of COV mode and main app screen shows 98%.
It will take a charge and while watching cell voltages, I saw a drop on one cell to 1.130 right before the COV kicked back on.
This forum has been more helpful than Signature Solar Support.

 

[sunshine_eggo]

@paticus How old is your EG4 that goes into COV mode?

I have an issue with my new EG4 WP 12V 100Ah going into COV mode under similar conditions (near 100% charge and 13.8VDC).
Disconnecting the battery and letting it discharge a minute (small 5-10A load) gets it out of COV mode and main app screen shows 98%.
It will take a charge and while watching cell voltages, I saw a drop on one cell to 1.130 right before the COV kicked back on.
This forum has been more helpful than Signature Solar Support.

IMHO, you have a sense lead error or BMS error. When you sum 1 + 2, and divide by 2, you get 3.38V, which is reasonable for the other two cells. Sense lead/connection problems often result in nutty cell voltages that make sense when you sum and divide by 2.

Also worth verifying BMS values with an actual meter on the cell terminals.

 

[Spd_Rcr]

IMHO, you have a sense lead error or BMS error. When you sum 1 + 2, and divide by 2, you get 3.38V, which is reasonable for the other two cells. Sense lead/connection problems often result in nutty cell voltages that make sense when you sum and divide by 2.

Also worth verifying BMS values with an actual meter on the cell terminals.

@sunshine_eggo I totally missed cell voltage #2 (holy cow!)

EG4 WP is waterproof and sealed (and also still under warranty).
This model does have 2-pin com port on the top and between the main terminal posts.
Any way to verify values without opening the case?

 

[sunshine_eggo]

@sunshine_eggo I totally missed cell voltage #2 (holy cow!)

EG4 WP is waterproof and sealed (and also still under warranty).
This model does have 2-pin com port on the top and between the main terminal posts.
Any way to verify values without opening the case?

Not that I know of. I would say you have evidence of a defect and a valid warranty claim.

 

[EG4_Jared]

I totally missed cell voltage #2 (holy cow!)

EG4 WP is waterproof and sealed (and also still under warranty).
This model does have 2-pin com port on the top and between the main terminal posts.
Any way to verify values without opening the case?

The COM port is currently non-functional. I would recommend contacting the distributor from whom the purchase was made to verify whether opening the battery for troubleshooting purposes would invalidate the warranty. You could also attempt separately charging this battery with a battery charger to see if the cells will balance.

 

[Spd_Rcr]

Hi @EG4_Jared thanks for that suggestion on cell balancing!
What specific steps does EG4 recommend?

It would be helpful to know how to balance the cells as per the manufacturer's recommendation.
Voltage amount?
Amperage?
Length of time?
What should I watch for and expect to see from within the EG4 app?

 

[paticus]

I dropped my float and absorption down to 13.5 for a week, and the problem is solved!! All 3 batteries are balanced, and the cells as well. Thanks for the help!

I do need to raise the values back up but I will do that incrementally and keep an eye on the cells.

 

[PotusGobbleBottom]

I dropped my float and absorption down to 13.5 for a week, and the problem is solved!! All 3 batteries are balanced, and the cells as well. Thanks for the help!

I do need to raise the values back up but I will do that incrementally and keep an eye on the cells.

Good to hear! Did you use the battery during this week or just let it sit?