JK BMS in boot loop

[Brownie Solar]

They say it is a custom chip, I've inspected it under a microscope and there is nothing written on it... I hope the replacement chip is an updated version!

 

[Brownie Solar]

If it ends up that mine cannot be repaired or they replace it, I will mail my failed one to you.

I work for a company who designs and manufactures prints for charching stations for Electrical Vehicles, RTU's and modems. I have literally seen, tested, inspected 10.000s of prints, and I have to say who ever manufactured this one did a very, very nice job! So may you can open them up and compare them both, if they replaced some components on the new one, usually it can only be done by hand, you will see it with the naked eye. If it is hardware version 11.x.y that is btw mine is V11.1.1

 

[hwse]

I will be installing mine this weekend so i will check the build number once it is up and running. As far as I am aware, it can only be accessed by the app, correct?

 

[Brownie Solar]

I will be installing mine this weekend so i will check the build number once it is up and running. As far as I am aware, it can only be accessed by the app, correct?

The app will say hardware version V11.XW, the actual HW version is written on the print.

 

[hwse]

I got my new BMS running and here is the "about" page. I am running version 8.4.5 of the app.

 

[Albion]

I had the beeping problem the BMS being on boot loop. It appeared immediately when I started the app on 30th september to have a look on the BMS status. I disconnected the BMS to restart but nothing changed and the app wasn't able to connect. I pushed the power long time (20s ?) and when I let it come back, I discovered that was getting off the BMS. Trying to connect the app multiple times, It same some times randomly but wasn't able to act on the BMS.

Finally, a had a look about the app on PlayStore and I saw that it was a new version published the 14th september. So I got an older APK version ( the 4.8.5) from here : https://www.pgyer.com/Cfq3. And it worked. I had other boot loop when I tried to change settings. I uninstalled the app and reinstalled it, maybe 3 times, and finally It's now working normally.

When I tried to reinstall the last app version (the 4.9.1) and launched it I got immediately the crazy beeping of the boot loop. So as I never had problems before, no special use of the battery, and it possible I didn't launch the app since it was updated the 14th september, I suspected that the problem was coming from the 4.9.1 version of the app. But it looks like others have the problem with older version ...

 

[Sprks]

I have just experienced the same exact issue... confirmed it has the symptoms as described by @hwse in his video. Here is a sequence of events:
1. Replaced a CerboGX touch screen and the wifi was not connecting. I shut the battery/system off thinking a reboot might fix it.
2. I neglected to shut off a roof top solar panel before main switch off, realized my mistake when lights remained on.
3. Shut off solar panel, main switch on again and immediately had JK app error of "irregular cell count" resulting in bms shut down.
4. Since then i have the issue described here... beeping, boot loop, no app connection.
Did i FU leaving the solar panel on? I will reach out to JK on aliexpress.
FYI i do have one of the very first units availab

 

[John Frum]

@WilliamFR has a similar problem described here https://diysolarforum.com/threads/jk-bms-doing-odd-things.49386/

 

[WilliamFR]

I have just experienced the same exact issue... confirmed it has the symptoms as described by @hwse in his video. Here is a sequence of events:
1. Replaced a CerboGX touch screen and the wifi was not connecting. I shut the battery/system off thinking a reboot might fix it.
2. I neglected to shut off a roof top solar panel before main switch off, realized my mistake when lights remained on.
3. Shut off solar panel, main switch on again and immediately had JK app error of "irregular cell count" resulting in bms shut down.
4. Since then i have the issue described here... beeping, boot loop, no app connection.
Did i FU leaving the solar panel on? I will reach out to JK on aliexpress.
FYI i do have one of the very first units available.

man..i tried reaching out to Hankzor but he gave me kind of a run around copy/paste response. So in the event the thing just malfunctioned on it's own..i lost my $200. I just purchased a new one from Docan Power and it should be here today.

 

[Sprks]

I have just experienced the same exact issue... confirmed it has the symptoms as described by @hwse in his video. Here is a sequence of events:
1. Replaced a CerboGX touch screen and the wifi was not connecting. I shut the battery/system off thinking a reboot might fix it.
2. I neglected to shut off a roof top solar panel before main switch off, realized my mistake when lights remained on.
3. Shut off solar panel, main switch on again and immediately had JK app error of "irregular cell count" resulting in bms shut down.
4. Since then i have the issue described here... beeping, boot loop, no app connection.
Did i FU leaving the solar panel on? I will reach out to JK on aliexpress.
FYI i do have one of the very first units available.

@Nami

I appear to have solved my issue... id forgotten that my inverter/charger needs an initial charge up for the capacitors before it turns on. It was demanding this from the battery when the bms starts and the bms doesn't quite turn all the way on.... so i charged up the capacitors in the inverter (just hooking up the shore power) and now ive got the JK back working again. So, if you have ANY loads, including an inverter needing its caps charged up, make sure they are disconnected before firing up the bms... I am, however going to order another jk bms for back up.

 

[hwse]

That was not my problem. I thought that it might have something to do with overloading on startup, so I removed the class T fuse on the B+ cable so there was no load on it. Just the four cells connected to the bms and the B- from cell #1 to the bms. no difference.

 

[Sprks]

I appear to have solved my issue... id forgotten that my inverter/charger needs an initial charge up for the capacitors before it turns on. It was demanding this from the battery when the bms starts and the bms doesn't quite turn all the way on.... so i charged up the capacitors in the inverter (just hooking up the shore power) and now ive got the JK back working again. So, if you have ANY loads, including an inverter needing its caps charged up, make sure they are disconnected before firing up the bms... I am, however going to order another jk bms for back up.

NOPE. problem recurs again. Every time i open the app i get a shutdown. First error is "cell count unequal to settings" I have messages into Hankzor on AliEx, but have yet to hear back. Last log shows this:


Replacement units (2a) are not available, was told "available next week" . I am hesitant to reorder due to lack of response, but im kinda locked in to this bms with my 24V system....
@Nami

 

[John Frum]

NOPE. problem recurs again. Every time i open the app i get a shutdown. First error is "cell count unequal to settings" I have messages into Hankzor on AliEx, but have yet to hear back. Last log shows this:

View attachment 118588
Replacement units (2a) are not available, was told "available next week" . I am hesitant to reorder due to lack of response, but im kinda locked in to this bms with my 24V system....
@Nami

Do you have a bad sense lead?

 

[Sprks]

Do you have a bad sense lead?

Perhaps, but it only seems to happen when i open the app. I will check continuity of the leads now.

 

[nc73]

Good thing I have a backup JK on hand.

 

[SolaroSsaurius]

Have to have a backup is not reassuring...
Though I bought JK-B2A8S20P-H last week... let's see how it goes...

 

[nc73]

Have to have a backup is not reassuring...
Though I bought JK-B2A8S20P-H last week... let's see how it goes...

Only because a new bms is weeks away if I had to order one.

 

[Sprks]

Perhaps, but it only seems to happen when i open the app. I will check continuity of the leads now.

Sense wire continuity is good. Cell count error is not returning, yet I am able to restart the bms only occasionally. This began out of the blue after the last version update. Hope the seller will make it right.....

 

[John Frum]

Sense wire continuity is good. I am able to restart the bms only occasionally. This began out of the blue after the last version update. Hope the seller will make it right.....

Just for a test try disabling the charge FETS and see if it will stop the boot loop.

 

[hwse]

On mine, when it was in the boot loop it could not log into the app so there is no way to change the FET settings.