NORMAL - cell voltage deviation at 13.8 volts while charging at 10 amps

[Bobert]

My batteries (inferior brand compared to sok) did not internally balance the seller sent me add on internal balance board that eventually fixed the problem but it took well over a dozen cycles before I didn’t hit high cutoff early.

 

[Aly_Oops]

I received another sok 206 battery. Despite doing several proper discharge as per instruction on their web page i end up with 400mv balance difference. The balancing is perfect until it reaches 90 percent charge and goes off balancing. Still testing to see if gets resolved. Abc bms is the worse Bluetooth app. Wont even allow you to see the parameter. Ok don’t allow changes but why not view it. Weird. What r they hiding.

I notice the bms wont allow the battery to go over 13.89. It shut off the battery and if one cell hit 3.69. It shut off balancing and wont change until it discharges a bit.

They advertise total voltage shutoff is 14.8. If that is so then balancing could happen. Looking into it

 

[MisterSandals]

I notice the bms wont allow the battery to go over 13.89.

Try lowering this until you get thru charging without hitting cell over volt. I only charge to 13.8V and consider it 99% charged. I hope (expect?) these cells to last longer with gentle day to day treatment.

EDIT: just saw 10A charging in title... that is pretty gentle already!

Charging at lower amps (you can play with this too) will get you a better, more absorbed charge than a hard high amp charge to you top voltage. Setting the charge amps is a bit of a balancing act; set it just high enough to complete but low enough it doesn't hit BMS cell over volt.

It shut off the battery and if one cell hit 3.69. It shut off balancing and wont change until it discharges a bit.

Sounds like its working as designed.

The balancing is perfect until it reaches 90 percent charge

What do you consider "90 percent charge"?

 

[sunshine_eggo]

I received another sok 206 battery. Despite doing several proper discharge as per instruction on their web page i end up with 400mv balance difference. The balancing is perfect until it reaches 90 percent charge and goes off balancing

No it's not. "Balance" refers to state of charge (SoC), not voltage. The only time voltage is an indication of balance is in the upper leg of the charge
curve above 3.40V/cell. Even grossly imbalanced cells will show near identical voltages in the operating range.

Still testing to see if gets resolved. Abc bms is the worse Bluetooth app. Wont even allow you to see the parameter. Ok don’t allow changes but why not view it. Weird. What r they hiding.

I notice the bms wont allow the battery to go over 13.89. It shut off the battery and if one cell hit 3.69.

Then you should float at 13.8V.

 

[Aly_Oops]

Well sok agreed with my diagnostic and sending replacement.

When i mention perfect balancing. I was referring to cell difference was within 2 mv.

Best to read the concept of message. Not the grammar. Spelling. Etc. or too ……..

 

[sunshine_eggo]

Well sok agreed with my diagnostic and sending replacement.

As they should.

When i mention perfect balancing. I was referring to cell difference was within 2 mv.

Which is incorrect. voltage does not represent balance except in the upper and lower ranges of the curve. Very imbalanced cells will have resting and operating voltage right on top of each other.

Best to read the concept of message. Not the grammar. Spelling. Etc. or too ……..

Best to communicate effectively rather than perpetuate an incorrect concept.

 

[Aly_Oops]

I use only Victron system and glad I went that way. Normally it is set to disconnect at 10 percent. Ran it until it disconnected the system, I took a measurement and the BMS didn't shut down. Their app was still showing it was active too. I hook up a 200 watt DC heater/fan, until it shut down, however, I still had 1 volt, BMS seem to be sitll active. Their app was still showing it was active too. So, used the heater as a resistor load and then it shut down. The app was no longer active. I had to use my victron bluesmart charger to wake it. Hey, votage not good enough, that okay, I used several methods. I was asked by SOK to measure the voltage. Why the attack..... Weird....

SOK wanted the BMS to shut down and this was the method I used. It worked, so what is the big deal here. Some need to find fault, critized, look for general statements to find fault. The purpose of the forum is to share one's experience and solutions, not to brag or act like a know it all. Too many people on a forum like that, will only cause people to leave the forum.

I do not think, this extreme method should be necessary, but I was asked and so I did it. So please, don't attack this.... You are missing the point. Get a life....

Regarding the ABC-BMS app, it the worse app I every used. Doesn't do much.... They won't even allow to view the parmeter settings. I can understand locking out some changes. In areas where there is a range that is acceptable to play with, they could allow that. Quick example: Perhaps you want to have the battery shut down at 5 degrees, instead of 0 degress. No harm to do that. If you put a value that can cause harm, it rejects the settings.

Those who have reviewed the SOK batteries, did a nice job taking it apart, nice packaging, servicing, do the capacity test. But nothing on how the balancing was, 450mv is not good, don't even like 200mv differences. Nothing on the app! Was it any good. Can you make changes. Can you even access the parameters. NIL, NIL. Very incomplete reviews and as a result people bought the unit only to find out it shortcommings afterwards.

No stars for their reviews..... click bait only. Pride will move them to find fault again..... never ends... Instead of attacking, give solutions, suggestions. Why be critical? Saying it incorrect on details type from a phone, written on the fly. Give a solution, suggest a better widget. If you can't, don't comment....

Regarding the other SOK battery, SOK agreed with my diagnostic and sending me a new BMS......

 

[vanwagon]

I'm super disappointed with SOK. 3rd battery arrived today.

First had nearly zero mV on one cell viewed through the ABC app. Something like 0.375V while the rest were around 3.550v. Sent back.

Second battery showed up. Obviously used. Screws missing from lid. Scratched up. Refurb probably but not even put back together. Sent back.

Third arrived today. ABC app shows SOC 0v. Standby?
Cells are: 3.195v, 3.195v, 3.193v, and 2.563v.
The battery is still in the box. I just connected the app before opening it because of my two previous issues. Are those voltage differences and issue? Will this be a balance issue ? Are the cells depleted more than acceptable for a new battery at 3.19 to 2.56v?

I'm tired of dealing with this but don't think this looks like normal for a new battery... Or is it

 

[sunshine_eggo]

IMHO, send it back.

 

[Bud Martin]

I'm super disappointed with SOK. 3rd battery arrived today.

First had nearly zero mV on one cell viewed through the ABC app. Something like 0.375V while the rest were around 3.550v. Sent back.

Second battery showed up. Obviously used. Screws missing from lid. Scratched up. Refurb probably but not even put back together. Sent back.

Third arrived today. ABC app shows SOC 0v. Standby?
Cells are: 3.195v, 3.195v, 3.193v, and 2.563v.
The battery is still in the box. I just connected the app before opening it because of my two previous issues. Are those voltage differences and issue? Will this be a balance issue ? Are the cells depleted more than acceptable for a new battery at 3.19 to 2.56v?

I'm tired of dealing with this but don't think this looks like normal for a new battery... Or is it

Man! that is really bad.
May I ask who the seller is?
Did they advertise them as new batteries?

 

[vanwagon]

SOK 12V100Ah LiFePO4 Battery Bluetooth&Built-in heater | SOK Battery

In stock now, ready to ship! Latest V8 version Bluetooth BMS, top battery cells balance function. SK12V100H designed for cold weather using! Can safely charge at temperatures down to -20°C (-4°F) by a standard charger or solar charger. The heater pads which draws power from the charger...

www.us.sokbattery.com