Schneider xw pro 6848 not powering up with eg4 lithium battery

[Mr-Sandman]

@Koldsimer if I was cycling my batteries like you daily, I would probably charge them with a little higher voltage than I am using. I purposely don't wont my batteries at 100% as I've read that's not a good way to "store" them.

 

[Koldsimer]

View attachment 96021
I can't tell from that image if you are connecting that negative cable all the way down to the bottom of the negative busbar or at the top like it was shipped as? If you didn't flip that negative busbar around you'll be putting a lot more wear on that top battery compared to the bottom one.

I didn't flip mine and surprisingly i haven't noticed anything more than 1% difference in soc and they always seems to be pulling within .1 or .2a of each other.

But yeah, that being said, im going to flip the negative next time i have the system down for some time. Just out of principle.

 

[Koldsimer]

When I manually cycle them "pull them down to 10% or so and recharge to 100%" I use higher voltage "56 volts if I recall". I forget the exactly threshold, but the SOC indicators re-zero to 100% and the BMS will shut charging off to them. I do that every couple months or when I think about. Looking at the individual cell voltages they stay close except for 1 cell in 1 battery it always has been about .1 volts low. Probably in issue, I probably should reach out to signature solar about that.

Two of my modules consistently show one cell that's .15 behind.

 

[Mahendra Gomanie]

Do you have any balancing issues running them at those voltages? Have you checked individual cells to see if anything is extremely high or low? I thought the bms needed the higher voltage to properly balance cells.

The latest numbers i saw on Signature and SOK both recommend 57.7 for absorb but that seems high to me.

I just started running them at 57.5 the other day after i added the SOK. They had been at 56.5 absorb but i recently noticed some large cell voltage gaps and figured i'd try the higher voltage to see if it helps balance things out.

Ok .well if thats recomended then i guess they are right.
Because i saw a fortress battery recently that looks like it has been suffering from a self impose parasitic drain that is caused by low absorb and float voltage of 54.6 absorb and 54.4 float .
These are recomended by fortress .
Unfortunately this is the 10k version with no app or means to monitor cell botages or balancing.

Cranked the voltage to the highest allowed b fortress and it was ok

 

[Mahendra Gomanie]

When I manually cycle them "pull them down to 10% or so and recharge to 100%" I use higher voltage "56 volts if I recall". I forget the exactly threshold, but the SOC indicators re-zero to 100% and the BMS will shut charging off to them. I do that every couple months or when I think about. Looking at the individual cell voltages they stay close except for 1 cell in 1 battery it always has been about .1 volts low. Probably in issue, I probably should reach out to signature solar about that.

.1 is a lot .
You definitely need to look at that.

 

[Mahendra Gomanie]

Two of my modules consistently show one cell that's .15 behind.

Now that you guys are mentioning this.
I did observe in two of the battery packs that the cells seemed unbalanced.
This is both from overkill bms and my dmms (klien tool dmm,fluked dmm and astro AI dmm.)
I will know for sure after a recharge and monitoring of the bms.
I never did got the SS bms to connect to the computer. I EVEN HAD AN IT guy have a go at it with no sucess.

 

[Mahendra Gomanie]

Two of my modules consistently show one cell that's .15 behind.

I wonder if these cells are factory top balanced and if yes how properly was it done.
I see anc p grade for active /smarter balancing bms in the future

 

[400bird]

Haha, the simple solution would have been an external pre-charge.
The complex solution chosen here was different batteries

 

[ChrisG]

Haha, the simple solution would have been an external pre-charge.
The complex solution was different batteries

You mean like a resistor before attaching cable fully or jumping a DC switch with a resistor?

 

[400bird]

You mean like a resistor before attaching cable fully or jumping a DC switch with a resistor?

There's more than one way to precharge an inverter.

A resistor across a breaker is the probability the best choice.

Do a forum search for precharge and you'll probably come up with hundreds of options from using an incandescent light bulb, long run of small gauge wire...

 

[ChrisG]

There's more than one way to precharge an inverter.

A resistor across a breaker is the probability the best choice.

Do a forum search for precharge and you'll probably come up with hundreds of options from using an incandescent light bulb, long run of small gauge wire...

So all of this EG4 battery crap was because the batteries didn’t precharge the way the are supposed to? Watched Richard’s video several times.

 

[FilterGuy]

Watched Richard’s video several times.

Which video? Got a link?

 

[ChrisG]

Which video? Got a link?

The startup procedure:

 

[Mahendra Gomanie]

So all of this EG4 battery crap was because the batteries didn’t precharge the way the are supposed to? Watched Richard’s video several times.

?yes

 

[FilterGuy]

The startup procedure:

Thank you. I had not seen this video before.

It is interesting that when Will talked about this he described a much more complex sequence to do the precharge. The way the video describes it is much simpler.

 

[Mahendra Gomanie]

Thank you. I had not seen this video before.

It is interesting that when Will talked about this he described a much more complex sequence to do the precharge. The way the video describes it is much simpler.

Hmm.
So what if you are using a growatt 12k or 20k with lots of eg4 on racks.
Since one eg4 should be used for 4kw inverter max.
Don't wanna say I tried.all of this and it.did not.work

 

[400bird]

The startup procedure:

I hadn't seen than either.

Immediate stumble:
"To start your precharge you need an open electrical connection to your inverters" he then proceeded to describe the opposite of an open...

 

[FilterGuy]

In the video, he dances around something I have been wondering about since they released the EG4 batteries.

The LiFePower4 battery manual has this:



A single 48V 6500W inverter running with 100% efficiency will draw 135A. At a more realistic 95% efficiency that goes up to 143A.

The spec says 100A max so two of them can drive a single 6500W inverter. However, what the heck does the "30A Recommended" mean???
If I go by the recommendation I would need 143A/30A/Battery=4.75 or 5 of the EG4 batteries!!!

I have seen this question asked several times but I have never seen an answer.

 

[ChrisG]

So then there is no fix or working procedure for the EG4 batteries yet outside of using a self defined precharge resistor method or does that not even work?

 

[ChrisG]

In the video, he dances around something I have been wondering about since they released the EG4 batteries.

The LiFePower4 battery manual has this:

View attachment 102478

A single 48V 6500W inverter running with 100% efficiency will draw 135A. At a more realistic 95% efficiency that goes up to 143A.

The spec says 100A max so two of them can drive a single 6500W inverter. However, what the heck does the "30A Recommended" mean???
If I go by the recommendation I would need 143A/30A/Battery=4.75 or 5 of the EG4 batteries!!!

I have seen this question asked several times but I have never seen an answer.

Funny I just read that thread with the pylontech batteries. Signature Solar never gave a a real answer.