B230 self discharge rate

Yeah, I can try my work phone (Iphone). The one in the picture is Android. Or I could install the app on an android emulator on my laptop, that might be the best option as the laptop is much much newer and has better Bluetooth.

Alright, I’ll try again when I get home. Got the app installed on my work Iphone here since I don’t have cell service where I live.

I am extremely relieved to report that on the newer (IOS) company phone the bluetooth connection had no issues, and the firmware upgrade went through without bricking anything.

Charging the problem b230 back up from zero, will see if it holds a charge now.

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Alright, post-firmware update, the stack (AC200 Max with 2 b230 batteries) delivers 4.1 KWH of useable power from 100% charge down to zero at a 300 watt load, according to the Kill-a-watt meter. Charging from 0% to 100% takes 7.1 KWH of power using the 400 watt AC charger, again using the kill-a-watt meter.

Have not had time to see if the problem cell hold a charge overnight yet, yesterday’s tests were for capacity.

@m.briney BMS 1010.08 version

  1. Introduce SOC small current charging correction accuracy to prevent excessive SOC error.
  2. Modify the SOC of B230 through AC200MAX control deployment to improve the accuracy of B230 display SOC.
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It sounds like your numbers are getting closer.. 4.1kwh out of the advertised 6.144kwh rated capacity (ac200max + 2xb230 batteries) is right around 67%. But I would absolutely do a couple more COMPLETE cycles, since performing the update, and I bet that number will only increase from there. :muscle:
And if you're not a member of our facebook group @Emperatorzacks I would suggest joining that as well and checking out this post that my buddy Jeff Hagen has written up regarding the ac200max and b230 and his testing results with such. Lost of valuable info on there as well.

Heres the link to one of the posts but you can search within the group and see many more…

Yeah, I have only done one complete cycle since the update. Will do a couple more and see if it improves.

On the overnight self discharge test:
Unplugged and disconnected and turned off everything with all 3 units around 70% last night. This morning I connected everything and turned it all on, expecting the problem b230 to have dropped to zero as it often does.

NOPE. The problem b230 had jumped from 70% to 97% overnight. Also reflected in the indicator lights on the front of the b230. Call Ghostbusters? Just kidding, will do a couple more charge/discharge cycles and report back.

Thanks for the Facebook suggestion, I’ll check it out.

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I was out of town for a couple days and left the system off and unplugged. Problem b230 only lost 4% charge during this time. I’m beginning to have hope! Thank all of you for your patience and help.


@Emperatorzacks Sounds like progress is being made for sure! :metal:

Yeah, improving, it seems. Won’t have time to do a couple more cycles until the weekend. Turned everything off last night at a bit below 30% charge, problem b230 had dropped to 0% overnight. Still seems to lose charge if it’s at a lower state. I think my next test is to charge the bad one on it’s own from 0 to 100 with the ac charger to see what it’s capacity is seperate from the rest.

Charging the problem b230 from 0% to 100% took .84 KWH on the AC charger, as measured by the kill-a-watt meter.

Discharging the problem b230 from 100% to 0% using an inverter from the 12v output, delivered .67 KWH of electricity as measured by the kill-a-watt meter.

As a last test I charged it up to 30%, turned it off, and after a couple hours turned it back on. Yep, 0%.

Pretty sure that pack has some bad cells or something, but will continue charge/discharge and see if it improves, only done twice so far.

Sounds like you are on the right track. I would agree that this is more than a calibration or cold weather issue.

The problem b230 continues to deliver around 1/3 of the expected output despite repeated full charge discharge cycles. It also continues to randomly loose significant charge when off and disconnected, usually around 30% but occasionally more.

Guess it’s just defective. Does anyone know if these things use some kind of standard publicly available cells in their packs? I’m guessing it’s probably just one or two bad cells ruining the whole pack, might be fixeable cheap with a bit of soldering if that’s the case.

Note that if I just use the AC200 Max with the good b230, everything works perfectly and as expected.

Go to “data” and then “BMS information” and then click the upper left hand corner 5 times and it will display all the individual cell voltages. This will show you if you have defective cells.

Isn’t that just for the main unit, not the b230’s?

Ah, figured it out, you have to push the number to cycle through. Thank you. All cells all packs are 3.33V give or take .01V, at a charge level around 40% for the packs so I guess that’s not it.

Lithium cells always average toward the nominal voltage on idle (for LiFePo4 it’s 3.2 volt), so you can’t find a bad cell (in your case a group of cells in parallel) on a low SoC.
Please charge the pack and follow the cell voltages on the balancing stage that’s from about 98% to 100%.
On a balanced pack 100% is reached when the BMS detect a first group of cells at 3.55 volt. All the other groups should not be too distant at that point, usually < 0.10 volt.

I had no idea. Thank you, I will check them again when they’re at full charge.