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How to balance batteries?

Brucey said:
Your batteries are fine, but likely the SOC level is giving you garbage readings. If you don't have time for the nonsense with weeks and months of back and forth with support just disregard the soc and trust in your shunt for SOC, use them in lead acid mode
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I do believe you are correct sir.
They are set to lithium but now that everything's updated, the batteries are good.
 
BarracudaBob said:
Wend down to 30% and back up. at 52% 52.6V @ 5A everything looked great and nearly balance then went up to 54.5V and it wen to crap.
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Interesting that it would seem as if the charging just stopped at some point. Cells look balanced. No error message?
Are the protection settings adjustable? If so I would be reviewing very closely to match with the others.
Need to focus on the range 52.6 to 54.5 and see what changes along the way. A separate ammeter for the problem battery might give some information if current drifts down or shows a hard stop compared to the others.
 
Gotshocked! said:
Hey BB, if you've got eg4 products, you might wanna give this dongle they send for free a shot. So far, it's worked for my system.
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Great Idea. I am having an issue with the Com Hub backlight flickering. They responded to the website inquiry and requested a video. I sent it to them and they are sending me a replacement hub. I asked for the updater so lets see what they say. No response about the battery issue. If it is just a hard case of being imbalanced (who me?) then I can understand that I have work to do. Been bring them up very slow to 54V tonight & tomorrow. I'll go for gold this weekend when I can watch them.

FYI, it was fun texting the wife and say turn off the breaker on the 4th from the bottom. I was remotely watching and would see a battery get to 20% and she would kill the breaker to that battery. We did that a couple of times as I drained them all down.
 
BarracudaBob said:
Great Idea. I am having an issue with the Com Hub backlight flickering. They responded to the website inquiry and requested a video. I sent it to them and they are sending me a replacement hub. I asked for the updater so lets see what they say. No response about the battery issue. If it is just a hard case of being imbalanced (who me?) then I can understand that I have work to do. Been bring them up very slow to 54V tonight & tomorrow. I'll go for gold this weekend when I can watch them.

FYI, it was fun texting the wife and say turn off the breaker on the 4th from the bottom. I was remotely watching and would see a battery get to 20% and she would kill the breaker to that battery. We did that a couple of times as I drained them all down.
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Tim from sig solar via email was giving me instructions to balance the batteries. They were incomplete.
I took the advice from MaikailifeDIY on pg 1 and got the battery update dongle from the link he provided.
It's been 3 days and the batteries all charge to 100% according too the inverter and the hub and by the end of the day, they're all off just a wee bit but then all charge right back to 100%.
I updated the batteries and sig solar updated my inverter remotely. I called them rather than email. Their support is tip top! Got right through to a tech in a couple minutes or less every time I called (3 times).
This worked for me but save yourself some grief and be sure to change baud on your comm hub to 19,200!!!
 
MaikaiLifeDIY said:
There are a lot of suggestions in this thread that are probably based on real-world experience and may trump this suggestion. However, the manual for the EG4 LifePower4 batteries suggests bulk/absorption to be at 56.2 (see page 5). Take from that what you will, others will have different opinions, but that's what the manual says.

You might also make sure you have the latest firmware on your batteries and Comm Hub if you don't already have that applied.

There is a dongle that Signature Solar is giving away for free that makes this pretty simple if you haven't updated your batteries.

signaturesolar.com

EG4 LifePower4 Automatic Updater Dongle

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL
signaturesolar.com signaturesolar.com

There is a promo code “lifepower4” that makes them FREE, including shipping.

Cheers!
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I am pretty handy with the computer and everything is up to date. Just ordered by updater with your promo code to make life simpler.
 
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BarracudaBob said:
I am pretty handy with the computer and everything is up to date. Just ordered by updater with your promo code to make life simpler.
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That pack is extremely out of balance, you have 0.245V deviation. I doubt your lowest cell at 3.354V is at full capacity, look at a LiFePO4 charge curve.
Do you have any way of doing a capacity test on that pack?

Without a BMS that has active balancing you will have to hold it ~55.6V for days to let the passive balancing BMS do its job.
I went through this with a DIY pack I didn't properly top balance, it stinks. I found it much easier to manually bring up the low cells with a bench power supply.
 
42OhmsPA said:
That pack is extremely out of balance, you have 0.245V deviation. I doubt your lowest cell at 3.354V is at full capacity, look at a LiFePO4 charge curve.
Do you have any way of doing a capacity test on that pack?

Without a BMS that has active balancing you will have to hold it ~55.6V for days to let the passive balancing BMS do its job.
I went through this with a DIY pack I didn't properly top balance, it stinks. I found it much easier to manually bring up the low cells with a bench power supply.
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I have tried everything except open it up and charge the lowest cells up with an external power supply. The BMS will lower the highest cells but it does nothing for the couple that won't come up. Lower voltages it looks great.
 
42OhmsPA said:
That pack is extremely out of balance, you have 0.245V deviation. I doubt your lowest cell at 3.354V is at full capacity, look at a LiFePO4 charge curve.
Do you have any way of doing a capacity test on that pack?

Without a BMS that has active balancing you will have to hold it ~55.6V for days to let the passive balancing BMS do its job.
I went through this with a DIY pack I didn't properly top balance, it stinks. I found it much easier to manually bring up the low cells with a bench power supply.
Click to expand...
At this point I don't see I have any other choice. The BMS will bring down the top cells but doesn't nothing to bring up the lower ones.
 
BarracudaBob said:
At this point I don't see I have any other choice. The BMS will bring down the top cells but doesn't nothing to bring up the lower ones.
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The BMS brings the top voltages down and when the battery is charged as a whole all cells will come up together.
Trouble is getting the top cells knocked down far enough. If there is an issue with some of the cells they may never equalize.
 
time2roll said:
The BMS brings the top voltages down and when the battery is charged as a whole all cells will come up together.
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You may need to use a charge current tht is less than double the BMS balance current. If it is just 60 ma, that means a 120 ma or 0.12 amp charge current for LONG time to bring a battery into balance. I would try abou1 amp to start and see if it can control it, but 0.5 or less may be needed with some low current passive balancers.
 
BarracudaBob said:
At this point I don't see I have any other choice. The BMS will bring down the top cells but doesn't nothing to bring up the lower ones.
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I know it worked well for me and I wouldn't hesitate to do it again if mine go out of balance that bad.

Another option, that would be slower, is to switch the inverter to grid pass through and charge the batteries at a very low current; somewhere under 5 amps. As the high cells drop the low cells should come up.

Edit- I see you have a chargeverter, that works too.
 
Gotshocked! said:
I'd back away from those batteries and just wait for that dongle to come in.
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They have the latest software in them. How is the dongle going to help besides make it easier to update next time? According to the SmartShunt the Charge set for 1 amp can still deliver up to 3 amps depending upon the voltage difference. Already tried walking them up a 0.1 volt at a time over days last week. Will have have to pick up a bench supply that goes up to 57V and set it up for 100mA. Hurricane season started today so I need something dependable. The Gov have issued their highest alert ever joy joy. I have the one on a Harbor Freight flat roller dolly that makes it pretty handy to move them around. Going to concentrate on some of my other projects. FYI, I have 4 Eco-Worthy that would reach full 56.2 before. Remote temp sensor to keep an eye on everything too. Here is an old pic.
1717293552534.png
 
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Shit. I must've missed that. I didn't realize you've got the latest. It appears to have fixed my issue, and I know how frustrating this stuff gets, and that's what I did.
 
42OhmsPA said:
What are your cell voltages / delta at a full charge?
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Right now at 70% they look good. They never make it to full charge. Somewhere in the 55V range they are 0.1-0.2 out of whack. Low cells never come up. I am going to isolate them and put them on a very low constant current with voltage peek of 56.2V and forget about them. Work week is coming up. Other things need to be attended to. I'll report back when I get things balanced.
 
The screenshot does not allow me to see all cell voltages. If one or more cells is above 3.45 volts then I should see "Bal" next to the cell voltage. If I blow up the picture it does appear (Although with my old eyes I can't be sure) that some cells might have "Bal" which is good. Hold the charge voltage between 55.2 and 56.0 volts to ensure that one or more cells does not reach 3.6 volts which is Cell Overvoltage Protection. If a cell reaches OVP then the BMS will stop the charge preventing other cells from balancing. Hold it there for a couple of hours and let the battery "soak". The juice (electrolyte) in the cells will become happy happy and hopefully all will be well. You might have to from time to time (hopefully not that often) do this but with all batteries in your bank. Balancing the cells in one battery is not the same as balancing all batteries together. I have one in a rack of six that always discharges first and also charges first. Not necessarily a "bad" battery, just a different batch and I might from time to time have to tweak the charge profile to accommodate this battery
 
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