JK 4s BMS not starting.

[hwse]

My 2s JK BMS has been working without issues since the beginning of July. Today I was installing new shore power charger and shut the BMS off with a long press on the power button and went about my install. After everything was connected, I pressed the JK power button and instead of the crisp "beep, beep beeeeeep" that I usually hear it just did random, irregular weak and distorted beeps. There was no pattern and it just kept on beeping but did not fully boot up. It showed up on the app list but I could not connect to it..

Any ideas on what to try?

 

[hwse]

I am not sure if it is relevant but the battery was just a bit more than 50% SOC when I turned it off. All cells were at 3.238b ±0.003v.

 

[Steve_S]

Cell voltages are good - should not be any issue there.
I'd think if it appears in the App, that it is up but faulting on something.
Have you tried to unplug the ON/OFF Switch & plug it back in ?
You most likely already checked all your connections and they are fine otherwise I'd imagine.
Upgrading the shore power charger should have no effect IMO as none of that is actually connected to the BMS. I would assume you tried with both Shore Power coming in and without it just to see if there is something odd.

Question(s):
A) Was the Inverter On or Off when you shutdown the battery pack ?
B) Was the Inverter ON when you tried to start the BMS ? (Could have pulled a surge for the capacitors)
C) Do you have a Pre-Charge circuit ? The BMS does not have pre-charge capability.

 

[hwse]

Cell voltages are good - should not be any issue there.
I'd think if it appears in the App, that it is up but faulting on something.
Have you tried to unplug the ON/OFF Switch & plug it back in ?
You most likely already checked all your connections and they are fine otherwise I'd imagine.
Upgrading the shore power charger should have no effect IMO as none of that is actually connected to the BMS. I would assume you tried with both Shore Power coming in and without it just to see if there is something odd.

Question(s):
A) Was the Inverter On or Off when you shutdown the battery pack ?
B) Was the Inverter ON when you tried to start the BMS ? (Could have pulled a surge for the capacitors)
C) Do you have a Pre-Charge circuit ? The BMS does not have pre-charge capability.

Thanks Steve.

A. There were no loads on at the time of shutdown. The battery selector switch was in the off position and the app showed 0.0A.
B. Same condition when I attempted to restart.
C. No precharge resistor but do not have a built-in invertor. The power is primarily used as 12v for 12v systems on a boat. I only have a 400W invertor and the switch on it is in the off position unless I am using AC. I was wondering if some type of surge might be causing the problem, so I removed the class-T fuse which disconnects the B+ so that it was completely isolated from everything else.

To shut down and the first restart, I did not even open the battery enclosure. The on/off switch is mounted so that the button is on the outside. After it did not start, I opened the compartment and made sure that all three plugs were fully seated, and I unplugged the sense plug and reseated it. I also checked the cell voltages with my multi-meter, and it showed the same as my earlier screenshot. The chargers are both off because I have not done the AC wiring yet. I tried to turn on the power for lights after I got done with the DC wiring so that I could turn off my headlamps and that was when I found the issue.

 

[hwse]

I have a replacement BMS on the way that should be here next week. This is the BMS that had its case mangled in shipping and I have been concerned about internal issues so had ordered a new one so that I could retire this one as a spare. Up till now it was performed without issue but do not know if this might have contributed to to the current problem.

 

[Steve_S]

I dunno what else to suggest for troubleshooting. Possibly you're right, something got weakened with the shipping damage, but I have my doubts about that.

 

[hwse]

any other suggestios as to how to start other than to unplug the on/off switch? I am going out to try that and will take a video of what it does.

 

[MisterSandals]

Today I was installing new shore power charger

Have you retraced the work that you performed? Your BMS functioned before the work, but not afterwards.

Happen to have a pic of the wiring? There are a lot of sharp eyes here that have found quite a few issues over the years.

 

[hwse]

Have you retraced the work that you performed? Your BMS functioned before the work, but not afterwards.

Happen to have a pic of the wiring? There are a lot of sharp eyes here that have found quite a few issues over the years.

This is my final configuration, and I did not remove the cover board from before I pressed the on/off button until after I tried to restart so nothing in this photo was touched. You can see the back side of the on/off button on the left side of the compartment.
All of the work done yesterday was to run two pairs of 8-ga wire from the +&- charge busses to the two new IP22 chargers. I also removed the three 2/0 cables from the old diode based isolator and placed the new ArgoFet in the same location and reconnected the three 2/0 cables.

 

[hwse]

delete

 

[hwse]

The three Victron items are the new install. Still have a little bit of wire management to finish off

 

[hwse]

Here is a link to a short video of what it does when I try to start it. The beeps are totally random in timing, sound and clarity. Some of them just sound like a hissing Noise. It will keep doing this until I manage to get it to turn off. sometimes I need to hold the power button down for up to 30 seconds to get it to stop.

2022-09-18_19-19-37

Shared from Screencast.com

www.screencast.com

 

[hwse]

@Nami can you shed some light on how to restart this BMS. If it cannot be restarted, I will need to start a warrantee claim.

 

[weeman]

Sounds like the BMS has died. I've got a JK 4S BMS which gets CPUAUX errors and 90% of the time when I first power it on mine does exactly the same with erratic beeping and hissing (although mine does eventually boot but then throws a CPUAUX error in the next 6-24hrs).

The other option for powering on without the switch is to apply a charge voltage 3-4v above the battery pack voltage (this was the only way to boot them before they started coming with switches). I'm guessing yours will have the same issue with this boot method though.

I'm sent a message to Hankzor on Aliexpress regarding mine by still waiting for a response. TBH these 4S models seem to have lots of issues compared with the previous 16-24S models (I'm running both).

 

[hwse]

Well, my replacement BMS showed up in the mail today so at least I will be able to get my system up and running again. I have not yet heard from Hankzor or @Nami about the failure of the first one.
It was just dumb luck that I had ordered a spare in October to replace this one which was damaged in transit. I did not think I could trust it long term with the physical damage it got. At the time I received it, Hankzor would not replace it and only gave me about 25% refund because it was still working. So much for that!

 

[fdom]

It sounds as it would be wise to cary a spare of the 8s version if it is installed in a more critical installation (boat or camper van)?

 

[hwse]

It sounds as it would be wise to cary a spare of the 8s version if it is installed in a more critical installation (boat or camper van)?

That is my intent and is why I ordered a second unit. Even though the first failed one will not be used, I want to get it replaced or repaired under warantee.

 

[Dreuf]

I have the same problem with my 4S BMS. "Bip,bip,beeeep".
Got a message from Hankzor to try the 4.8.4 version of the app.
Does the app load new firmware in the BMS? I don't think the Bluetooth is the problem here, but the firmware in the BMS who goes in a reboot loop.
I have asked Hankzor for a replacement, but from earlier experience I think I will need to send a message every day in a month until they answer..

Shame since it's a great BMS, only a slight problem that its not working...