SOK LiFePO4 Battery Possible Failure

[hugh]

Good luck getting this resolved. Your "real world" experience on their warranty service will be helpful for others looking at SOK products. Maybe you can point SOK to this thread.

Too many of these small tech companies provide long warranties that aren't worth the paper they're printed on. Let's hope that's not the case with SOK.

[Jane P.]

Originally Posted by DT6

I disconnected the batteries and was surprised. I connected to the Bluetooth in each battery and found them to be 43% and 41% charged, respectively. This, despite the Victron readout that said 100%. I can only assume the Victron was reading the solar panels?

BTW - when I disconnected them this afternoon, they had been hooked up to the solar panels for two and a half days of mostly sun. Certainly enough to have easily charged them back to 100% previously. Something seems very wrong if they are only at about 40%.

I purchased this pair directly from SOK.

Still waiting to hear back from SOK. I hesitate sending them screen shots of the new Bluetooth readings as every time I send a new email it seems to start the process all over again as they act like they never got a prior email from you. However, I'll certainly keep everyone posted on how well they eventually do in coming to a solution.

Your problem may lie elsewhere.

Last year, we had a similar problem. Battery not charging when off grid. Everything fine when hooked up.

We have a Battleborn 100 lithium. Victron BVM & MPPT RichSolar Solar Controller with Bluetooth.

Turns out the problem originated in our TV. A fuse to the 7-pin connector shorted out which caused the battery cable to the trailer to burn. No fire or damage to the battery itself because the Battleborn & solar controller shut down, as they were designed to do. We had the TV repaired, replaced the cable. Nothing needed to be repaired within the trailers lithium or solar system.

There was danger when under tow as our trailer break system did not work. In fact the break controller in the TV was our first clue that something was wrong.

BTW, I did call Battleborn & they worked closely with us to troubleshoot the problem. Once we got home, our service guy diagnosed the situation. IMHO, it’s really shitty of SOK’s customer service to ignore you. I am seriously thinking of going with SOK as a second lithium. Your experience gives me reason to pause.

Good luck. I’ll be interested to read about your resolution to this problem.

[DT6]

I'll just summarize most of my recent emails with SOK as being not very helpful and a lot of difficulty with language barrier. Communication has been difficult and in between one or two good suggestions was a lot of run around, repeated questions, SOK not keeping track of the email chain so I had to repeat myself several times. They also never answer their phone number.

SOK did finally offer to replace the batteries with new ones, which I will do in a few weeks after I recover enough from knee replacement surgery this past Tuesday (9/5). But it was not pretty getting there and I did hit finally my "Battle Born" limit (e.g. getting over the cost).

So I called Battle Born and they answered the phone (wow!) and the tech spent at least 15 minutes or so going over our trailer setup, our needs, and our comfort zone with respect to battery capacity. So we are going to go with their 270Ah "Game Changer".

If I were someone like many of you here on the forum who really understands AC and DC systems and how to troubleshoot, I'd probably keep the SOK's. But while I'm a decent statistician and mathematician, I suck at understanding electrical systems and my eyes just glaze over when I have to understand Ohms, Volts, Amps, etc, and I have no desire to get better at it (which is why I switched my major from EE to Applied Math).

We also had a few times last winter where we could have easily been stuck somewhere and possibly not been able to recharge with solar for several days (snow on the way to Reno, Tulare Lake suddenly reappearing and bringing traffic to a stand still, torrential rain/hail in Nevada and SoCal, etc.), so I wanted to add another 100Ah battery anyway as an emergency reserve. If we have another instance of issues with our SOKs while on the road I have zero confidence I could get the proper troubleshooting steps from SOK should we have another battery problem..

Battle Born on the other hand will answers their phone, and will also be able to walk me through any troubleshooting steps should we ever have an issue. If I did add a third SOK 100Ah and suddenly have issues, I have no confidence that they would be helpful in any kind of timely manner and would probably face the same issues with most other Lithium brands.

So when I finally get the replacements from SOK, I'll probably post them for sale. My sincere thanks to everyone who provided suggestions on this thread, it is very much appreciated. Once I'm able to be up and about (w/o a walker) I'll post them for sale.

Finally, I apologize if this is a bit rambling with grammar, spelling, issues as I'm still on pain killers and still in a lot of pain. Fortunately the doc says it was a great procedure and I should be good as new very soon.

[Perry Butler]

I knew of the problems that can occur from buying directly from any of the overseas companies. We chose to buy from their main US seller, Current Connected. I have 100% satisfaction in their response time and help. After talking to them I had new BMS modules in less than a week, even though shipped from China. The install was easy using the link to the YouTube video they provided. Took about a hour for the 1st BMS replacement and 20 minutes for the second replacement, but I still "measured twice to cut once."

The BMS now correctly displays SOC and CALC Capacity. I did get the batteries down to 2% last week, but the batteries will shut down if not charged for 9,999 minutes and they reached that before the last 2% was used. I disconnected the panels to see how many watts they will use in 100 F heat, but friends arrived and I forgot. I did get to charge on Tuesday in 98 F heat and they only put out 275 watts, but they're flat on the roof, we're in Minnesota, and the equinox is here in less than three weeks. On a cool day last June the 400 watt on the roof hit 370 watts.

Oh, I don't need or want a DC-DC controller, the Progressive Dynamics charger with Charge Wizard is removed, the Victron IP 22 charger is hooked up, but not plugged in, and I have no problems keeping the SOK's charged, including 3 months in last winter's cold in the SW states, with many many nights under 20 F and then we only had a 160 watt panel and our 100 watt portable.

Food for thought,

Perry

[CE Vogel]

Originally Posted by DT6

SOK did finally offer to replace the batteries with new ones, which I will do in a few weeks after I recover enough from knee replacement surgery this past Tuesday (9/5). But it was not pretty getting there and I did hit finally my "Battle Born" limit (e.g. getting over the cost).

So I called Battle Born and they answered the phone (wow!) and the tech spent at least 15 minutes or so going over our trailer setup, our needs, and our comfort zone with respect to battery capacity. So we are going to go with their 270Ah "Game Changer".

I hope you are recovering from knee surgery well. I have Renogy batteries, with similar customer service to SOK, but my batteries have worked well. From all accounts, Battle Born is a fine company with a fine product. You will probably be happy with them. There is one check I didn't see suggested you may consider: what is the battery voltage with all wires connected and the solar panels in full sun? It should be 13.8 - 14.4 volts, depending upon charge status of the batteries. If the voltage is less, you may have a problem in your solar charging system. Good luck!

[Mike G]

Likewise, trusting that the knee job went well (hopefully you can't kick! ) and that your recovery will progress quickly.

[DT6]

I appreciate the well wishes and I do seem to be recovering ahead of schedule thus far, but three days is not the finish line!

I also got approval from the new management at Escape to take our 21C to a local shop to diagnose the whole system as we are still under warranty albeit by a few weeks. They were also very responsive when I brought up several other issues that the prior management seemed to dismiss out of hand.

I don't know who took over but I definitely like the trend. We owned a 2018 19ft and it was put together very well, but we have had a lot of workmanship issues with the 21C that have already cost almost $1,000 in repairs due to sloppy workmanship.

I appreciate all the tips as well.

[sameo416]

Originally Posted by John in Santa Cruz

most multimeters handle a MAXIMUM of 10 amps, and have an internal fast blow fuse if that's exceeded. I generally avoid using this mode, and when I do need it, I have to be very careful with it. In particular be sure to switch it OUT of Amps mode the moment you are done, and move the + lead back to the normal + input port.

I agree!

I never use direct inline current measurement except on digital circuits where I know its constrained to mA. Apart from the blown fuse, making and breaking live higher current connections is something to avoid unless you’re really expert.

If you must make live higher current measurements a current clamp is a good investment, even just for the safety of use perspective.

With the measured different voltages on the batteries after charging, I’d say bms issues or sick cells. Li are very stable and repeatable if they’re working correctly.

[DT6]

I wanted to follow-up on what I think was the issue causing our battery problems. I'm not 100 percent sure this was the culprit, but it kind of makes sense.

When we picked up the trailer from Escape, the technician there had one of his folks wire up the two 100Ah batteries I brought with us. They did a standard parallel connection, which looked like what I had seen on some references I looked at.

Apparently that was incorrect. We had the trailer at our Camping World repair shop in Wilsonville, OR for some warranty work last week, and while looking everything over the electrical tech pointed out it was wired incorrectly for proper battery balance. Instead of connecting the red/black lines from one battery to the trailer charging source, and the second batter to the first battery, he connected one red from one battery to the charging source, and the black wire from the second battery to the charging source. He said that way both batteries drain and charge evenly. He also ran a wire and connected them to the Victorn bluetooth.

Since then, zero issues and it seems to be holding. Granted this is only what I've seen while it is on the street at our home, but we will be taking it out to Silver Falls this week, so I'll test them there.

Also, just prior to the tech re-wiring the battery cables, I recharged each battery separately at home with a standard lithium charger, so both were fully charged when re-installed and re-wired.

I'll report back if we run into battery issues this week. If no follow-up, assume all is fine.

[alanmalk]

Originally Posted by DT6

...
red/black lines from one battery to the trailer charging source,
...

I find that conclusion to be a little odd. I used the "incorrect" wiring pattern for 7 years with parallel AGM batteries - no issues.

But for full disclosure, when I changed to lithium I followed the "correct" wiring pattern for 2 parallel batteries. I also changed the grounding to use a single common copper stud. I have no way to prove or disprove which is "better" in actual practice, only on paper.

[oldwave]

https://www.victronenergy.com/upload...ted-pdf-en.pdf

See battery bank wiring for 4 correct methods

[alanmalk]

Originally Posted by oldwave

https://www.victronenergy.com/upload...ted-pdf-en.pdf

See battery bank wiring for 4 correct methods

If anyone is interested in the gory details: Read the Victron Energy discussion above, and then read the abstract from this paper:
Journal of Physics: Conference Series
"Real time monitoring state-of-charge battery using internal resistance measurements for remote applications"
The one sentence that should catch your eye:
"When charging process, the battery's internal resistance (ric) is low and will increase according with increasing the level of SoC." (Emphasis is mine.)

I would submit that the Victron diagrams showing "small current" and fixed internal resistance, are incorrect and by inference their wiring diagrams don't have fully demonstrated logic behind them.

What I am saying is that with variable internal resistance with SoC, the charges on each battery in the "incorrect" pattern will eventually balance - at least to the extent that is acceptable for camping.

Disclaimer - Before jumping on me, note that I did use the "correct" wiring pattern with my upgraded installation - because it felt good!

[SageRpod]

Originally Posted by oldwave

https://www.victronenergy.com/upload...ted-pdf-en.pdf

See battery bank wiring for 4 correct methods

I use method 4 of the examples. Used that on my previous trailer as well. Had zero issues.

[oldwave]

Originally Posted by alanmalk

If anyone is interested in the gory details: Read the Victron Energy discussion above, and then read the abstract from this paper:
Journal of Physics: Conference Series
"Real time monitoring state-of-charge battery using internal resistance measurements for remote applications"
The one sentence that should catch your eye:
"When charging process, the battery's internal resistance (ric) is low and will increase according with increasing the level of SoC." (Emphasis is mine.)

I would submit that the Victron diagrams showing "small current" and fixed internal resistance, are incorrect and by inference their wiring diagrams don't have fully demonstrated logic behind them.

What I am saying is that with variable internal resistance with SoC, the charges on each battery in the "incorrect" pattern will eventually balance - at least to the extent that is acceptable for camping.

Disclaimer - Before jumping on me, note that I did use the "correct" wiring pattern with my upgraded installation - because it felt good!

Perhaps if there is only two batteries which is majority of the applications here . Banks of 4 to 6 may never balance. Also most victron LiPO batteries have external bms except for a few models, they provide a much more accurate and controlled balance function. Alas I’m stuck with the SOKs with mediocre bms. I use example 4 and have had no issues.