78% SOC EG4 LifePower4 Capped Voltage

[girfold]

Hey all,

Per the title, I'm seeing a battery stop charging at 78%, just barely into the 4th light. The SOC on the EG4 3000 Inverter is showing 78%, but right around that time the voltage is sky-rocketing like it's full. Could it be a bad cell? But then the voltage should be even lower, right?

Some other thread was saying to keep it at 100% for 4+ hours and that it would see that the SOC is 100% and the BMS would reset the value but I let it do that over night and it still said 78% by the end of the night, same voltage of something like 56.4V which is the bulk charging voltage for Li4 setting in the Inverter.

Another thread was saying to change it from 56.4V charge to 57.2V and it would get to 100%, thoughts on that? I'll try it next time I disconnect the other 2 batteries in the group.

Another factoid, this battery is the V1 and the other two batteries that act normal are the V2 (for my above testing, I had these two batteries completely off to help rule them out). Also I'm using EG4 3000 V2. So this is the only component that's V1. SigSolar will probably be happy because my current thought is to buy a new battery and just use this potentially dud battery in the famous Will Prowse hand-cart inverter/battery setup.

Thanks!

 

[sunshine_eggo]

It's likely that it's just out of balance. @HighTechLab with Current Connected recommends you just continue cycling it, and it should resolve.

Alternatively, set to USE, absorption to 55.3V and float to 55.2V and see if it creeps up.

 

[Zapper77]

@girfold

What does the BMS Test program show?

Have you cycled the battery off and on?

How many batteries do you have?

What is the actual voltage when it is "capped"?

I wasn't aware the LP4 had different versions. Can you be more specific?

 

[Zapper77]

It's not uncommon for the BMS to report SOC inaccurately when new.

If the pack voltage reaches 56.5v the BMS should automatically reset SOC to 100% (Referring to BMS Firmware version 3.26)

Additionally just because the inverter reports 56.5v or higher, doesn't mean that the battery is actually at that voltage. You will need to review the battery data using bms_test program.

Assuming you have a Lifepower4 battery.

 

[HighTechLab]

It's likely that it's just out of balance. @HighTechLab with Current Connected recommends you just continue cycling it, and it should resolve.

Eg4 lifepower4 might act different than SOK. I am getting some EG4s on order to do some more thorough testing to see if they behave the same.

 

[girfold]

@girfold

What does the BMS Test program show?

Have you cycled the battery off and on?

How many batteries do you have?

What is the actual voltage when it is "capped"?

I wasn't aware the LP4 had different versions. Can you be more specific?

What does the BMS Test program show?
This is a good point, I should rig up my laptop with that to see that. I haven't used that before so maybe it will give some insights.

Have you cycled the battery off and on?
Oh yes, lots, and did the hold reset for 10 seconds as well. End result was that it didn't make any difference.

How many batteries do you have?
3 batteries, all the same EG4 vendor, but I ruled out any of the other battery issues by rigging the problem child up solo. I can see a clear difference in the 2 new ones and the 1 old one. The SoC LEDs have more of a shine in the 2 new ones, and a dull light in the old one.

What is the actual voltage when it is "capped"?
I wasn't aware the LP4 had different versions. Can you be more specific?
56.4V which is the bulk charge voltage for the typical Li4 setting from the inverter. Once it hits that, it doesn't do anything else. Once it gets into the 55V range at around 76% SoC indication, it goes up in voltage fairly quickly until capping out at 56.4V at 78%.

 

[girfold]

It's likely that it's just out of balance. @HighTechLab with Current Connected recommends you just continue cycling it, and it should resolve.

Alternatively, set to USE, absorption to 55.3V and float to 55.2V and see if it creeps up.

It's likely that it's just out of balance. @HighTechLab with Current Connected recommends you just continue cycling it, and it should resolve.

Unfortunately, it's been out of sync with the other two batteries for ~2 months. Here's an earlier thread I created before I found the issue was related to this single battery: https://diysolarforum.com/threads/eg4-x2-3000w-x3-48v-eg4-lifepower4-voltage-and-soc.64118/

Alternatively, set to USE, absorption to 55.3V and float to 55.2V and see if it creeps up.

With this being lower than the bulk charge voltage and the "capped" voltage, would it go up with that setting?

 

[Zapper77]

What does the BMS Test program show?
This is a good point, I should rig up my laptop with that to see that. I haven't used that before so maybe it will give some insights.

Have you cycled the battery off and on?
Oh yes, lots, and did the hold reset for 10 seconds as well. End result was that it didn't make any difference.

How many batteries do you have?
3 batteries, all the same EG4 vendor, but I ruled out any of the other battery issues by rigging the problem child up solo. I can see a clear difference in the 2 new ones and the 1 old one. The SoC LEDs have more of a shine in the 2 new ones, and a dull light in the old one.

What is the actual voltage when it is "capped"?
I wasn't aware the LP4 had different versions. Can you be more specific?
56.4V which is the bulk charge voltage for the typical Li4 setting from the inverter. Once it hits that, it doesn't do anything else. Once it gets into the 55V range at around 76% SoC indication, it goes up in voltage fairly quickly until capping out at 56.4V at 78%.

Push that one battery to 56.6v and see if it resets SOC to 100%

 

[Zapper77]

If you want to get way in the weeds you can download the BMS data logs directly from the battery.

 

[girfold]

It's not uncommon for the BMS to report SOC inaccurately when new.

If the pack voltage reaches 56.5v the BMS should automatically reset SOC to 100% (Referring to BMS Firmware version 3.26)

Additionally just because the inverter reports 56.5v or higher, doesn't mean that the battery is actually at that voltage. You will need to review the battery data using bms_test program.

Assuming you have a Lifepower4 battery.

It's not uncommon for the BMS to report SOC inaccurately when new.

It used to be fine before, but at some point it completely went out of sync and now is consistently nearly 25% missing SoC.

If the pack voltage reaches 56.5v the BMS should automatically reset SOC to 100% (Referring to BMS Firmware version 3.26)
So, I should force it to just a little bit more voltage to trigger this action? Assuming my BMS Firmware is up to date..

Assuming you have a Lifepower4 battery.
Yep, per thread title, not using the EG4 LL, just the EG4 LifePower4 one.

 

[Zapper77]

So, I should force it to just a little bit more voltage to trigger this action? Assuming my BMS Firmware is up to date..

Yes, that's exactly what I would do.

I've seen it and reviewed bms logs from my LP4 batteries that once they hit 56.5v it switches to 100%.

I also have one battery that likes to under report SOC if I go multiple days between a full charge. (After I bumped the bulk upto 56.5v it reset to 100%.)

Side question, I assume you are using battery comms...but your bulk and float voltage should be controlled by the primary battery BMS.

 

[girfold]

Yes, that's exactly what I would do.

I've seen it and reviewed bms logs from my LP4 batteries that once they hit 56.5v it switches to 100%.

I also have one battery that likes to under report SOC if I go multiple days between a full charge. (After I bumped the bulk upto 56.5v it reset to 100%.)

Side question, I assume you are using battery comms...but your bulk and float voltage should be controlled by the primary battery BMS.

Side question, I assume you are using battery comms...but your bulk and float voltage should be controlled by the primary battery BMS.

That's right, in normal circumstances I'm using the communications with different dipswitches across all three. It's the third in the array (bottom of the EG4 rack), and is not the primary BMS.. in normal setup. But during troubleshooting, I'd remove the other two batteries altogether by turning them off, updating the dipswitches, power cycling, then charging/discharging/cycling this single battery. At first I thought it was due to the fact that the bus bars needed to be flipped so that the load is across positive and negative and less strain on the top battery, so I did that and let it charge/discharge a week in hopes it would slowly get back in balance, but it never changed.