XiaoXiang BMS Spontaneously resets Remaining Capacity display

[Gazoo]

I was thinking about this one too, maybe even better?......

Charge-Discharge Monitor, DROK 0-90V 100A DC Ammeter Voltmeter, Battery Capacity Amp-Hour Watt-Hour Power Time Multimeter, LCD

It's probably overkill...but to be honest, I'm a tinkerer and enjoy it, so it's a hobby.

I am using a different more basic DROK monitor and it also has a hall effect sensor. Personally I prefer shunt based coulomb counters. I believe they are more accurate. I really like the JunTek I use with my Valence battery and I do recommend it providing one understands the few drawbacks it has and there are plenty of youtube videos explaining this.

 

[OnTheRoadAgain]

Something different has happened since I removed the generic vendor Xiaoxiang BMS and replaced it with the OverkillSolar BMS.

The OverkillSolar BMS has recalculated the Remaining capacity all by itself as someone earlier suggested and I had no idea what they meant. Now I do.
The other one never did this even though both are the exact same model BMS.

I bought in on Amazon and fortunately I'm within the return window.
I have to retract my earlier recommendation and now would advise avoiding the one on Amazon.

This is a big deal to me. I will stick to ordering from OverkillSolar from now on.

 

[Gazoo]

The OverkillSolar BMS has recalculated the Remaining capacity all by itself as someone earlier suggested and I had no idea what they meant. Now I do.

The BMS is going by the voltages entered in the voltage percentage settings of the BMS to determine capacity. Unless you get really lucky the ah's remaining will be off until you cycle the battery.

 

[Koontzy]

my aliexpress version of this bms is doing almost the same thing but almost only when I balance them. I then lose the ability to connect reliably. Also, I something change a setting in params setting and it do the same thing but usually it's when I reach the balance point. I think it just create too much interference when balancing so the bluetooth connection is getting hard time to stay stable. Also, the capacity is ... very unreliable.. I'm at the point to try to flash a new firmware (if I can find any). Maybe we can create a speadsheet with all the different version of these BMS (mine is JBD-SP04S020-L4S-120A-B-U, maybe we can decode the model number corresponding to the different option and version). From my understanding, the capacity is calculated only with the voltage chart that you setup in the parameter, which correspond to the specific cell voltage from the manufacturer (mine are CATL, finding a correct specs sheet is tough). One last thing is once the BMS "crash", I need to "cycle" it with either unplugging the charger if it's balancing or charging it if it crashed while messing the params setting

 

[HRTKD]

I asked a question about firmware on the Overkill Solar support site on Reddit. Only JBD has the firmware and they don't release it to the public.

 

[Koontzy]

I saw a version on endless sphere but did not try it

 

[OnTheRoadAgain]

The BMS is going by the voltages entered in the voltage percentage settings of the BMS to determine capacity. Unless you get really lucky the ah's remaining will be off until you cycle the battery.

I got VERY lucky I suppose. Or OverKillSolar has a better version? Hardware / Firmware?

I think maybe what I'm seeing is the aliExpress and RadioB BMSs' are not as reliable as the OverkillSolar BMSs for who knows what reason.

I'm sticking with OverkillSolar from now on. I don't like playing BMS Roulette.

 

[Bob B]

I hope once Overkill starts shipping again that the "new" ones don't have the same problem.

 

[OnTheRoadAgain]

I hope once Overkill starts shipping again that the "new" ones don't have the same problem.

My take on that is that Steve at OverkillSolar takes care of all that for us. He includes a data test sheet with every unit and backs it with an unconditional lifetime warranty. If there's an issue, he probably works with the supplier to iron out the issues.

That just might be the reason for the delay right now....the new batch may have had issues and Steve is having to get the supplier to fix the issue(s) ?? WAG. Or it could just be shipping delays also. I can wait. My money says Steve's high standards will result in the best bang for the buck

I was initially inclined to buy the cheaper ones off of aliexpress etc but I see that the little extra he charges for his is WELL worth the difference.
I'm not sure how he does it. I can believe he doesn't make much off of a sale.

I'm just really glad right now I had bought one from him a while back and had it on hand to replace the el cheapo that didn't work properly.
I was saving his to use on my batteries from Michael's group buy.

 

[ereams65]

Yes. The BMS basically does a full reset as if it was powered down completely.
I'm using 3.1.1026 from OverkillSolar's website which I think most people are also using?

The problem is that if it resets everything, then I cannot set parameters specific to my pack.

I'm using Version: 1.2.22, Build: 5391 on iOS

 

[OnTheRoadAgain]

I'm using Version: 1.2.22, Build: 5391 on iOS

I hear the IOS version is much better.
I can't use apple phones.

 

[HRTKD]

I hear the IOS version is much better.
I can't use apple phones.

Me either. I break out in a rash and want to hurl.

 

[OnTheRoadAgain]

In case anyone comes along to this thread late........

Problem solved: It was a bad generic Xiaoxiang BMS. Stick with OverkillSolar to avoid these headaches.

Ironically, it had not one, but two "Quality Control Passed" stickers on it.

Maybe I should post the serial number in case they sell it again after return, to one of you guys ?

 

[Gazoo]

I got VERY lucky I suppose. Or OverKillSolar has a better version? Hardware / Firmware?

I think maybe what I'm seeing is the aliExpress and RadioB BMSs' are not as reliable as the OverkillSolar BMSs for who knows what reason.

I'm sticking with OverkillSolar from now on. I don't like playing BMS Roulette.

Mine always gets thrown off by apx. 15 ah's when I change the parameter settings. For example the BMS displays 265ah's remaining when I fully charge my battery to 27.07 volts. When I change a parameter setting the BMS displays 250ah's remaining give or take a few, and it doesn't display properly again until I fully cycle the battery.

In the grand scheme of things it's not that much. If your newly installed Overkill BMS calculated the ah's accurately then maybe it has artificial intelligence or something....lol. If you ever fully cycle your battery again please confirm the ah's displayed are the same.

 

[HRTKD]

In the grand scheme of things it's not that much. If your newly installed Overkill BMS calculated the ah's accurately then maybe it has artificial intelligence or something....lol. If you ever fully cycle your battery again please confirm the ah's displayed are the same.

That's the AI plug-in that Steve puts on his version.

I can't say that mine have ever been off enough for me to notice.

 

[OnTheRoadAgain]

Mine always gets thrown off by apx. 15 ah's when I change the parameter settings. For example the BMS displays 265ah's remaining when I fully charge my battery to 27.07 volts. When I change a parameter setting the BMS displays 250ah's remaining give or take a few, and it doesn't display properly again until I fully cycle the battery.

In the grand scheme of things it's not that much. If your newly installed Overkill BMS calculated the ah's accurately then maybe it has artificial intelligence or something....lol. If you ever fully cycle your battery again please confirm the ah's displayed are the same.

Will do. To be honest, after getting a big zero on remaining capacity from the other dud, I'm really happy to be getting this even if it's an estimate.
The other dud just kept insisting on displaying the full capacity of the pack all the time no matter what the SOC was.
This is so much better.

 

[OnTheRoadAgain]

That's the AI plug-in that Steve puts on his version.

I can't say that mine have ever been off enough for me to notice.

This.
Even if it's not 100% accurate, it's close enough.

When the 100Ah battery is at 40% SOC, you'd much rather see "Remaining Capacity" 38Ah.....than 100Ah

 

[weeman]

Does the overkill version track small loads? I've got the generic JBD version from aliexpress and it will not read anything below around 0.5A. My vehicle mounted system has an idle load below this and can sit for a week or 2 without getting any charge so these small loads add up over time. Trying to debate if it is worth getting a Victron SmartShunt to more accurately track SOC with my use case.

 

[OnTheRoadAgain]

Does the overkill version track small loads? I've got the generic JBD version from aliexpress and it will not read anything below around 0.5A. My vehicle mounted system has an idle load below this and can sit for a week or 2 without getting any charge so these small loads add up over time. Trying to debate if it is worth getting a Victron SmartShunt to more accurately track SOC with my use case.

I don't think it's load dependent but I'm not 100 certain.

I charged mine yesterday 2.0Ah after changing to the OKS BMS and about an hour later I looked at it and it had adjusted the Remaining Capacity and I was pleasantly surprised. I could be wrong but I think it recalculates remaining capacity based on the voltages and a table it stores in memory.

I will try adding an amp hour at .5A amp see if it updates.

 

[Just John]

my aliexpress version of this bms is doing almost the same thing but almost only when I balance them. I then lose the ability to connect reliably. Also, I something change a setting in params setting and it do the same thing but usually it's when I reach the balance point. I think it just create too much interference when balancing so the bluetooth connection is getting hard time to stay stable. Also, the capacity is ... very unreliable.. I'm at the point to try to flash a new firmware (if I can find any). Maybe we can create a speadsheet with all the different version of these BMS (mine is JBD-SP04S020-L4S-120A-B-U, maybe we can decode the model number corresponding to the different option and version). From my understanding, the capacity is calculated only with the voltage chart that you setup in the parameter, which correspond to the specific cell voltage from the manufacturer (mine are CATL, finding a correct specs sheet is tough). One last thing is once the BMS "crash", I need to "cycle" it with either unplugging the charger if it's balancing or charging it if it crashed while messing the params setting

I will have to find it, but I have a spec sheet from them with a model number decoder.