JK BMS Discharge/Charge issue related to discharge MOSFET?

[Michael36]

Hello everyone,

I've been running a few JK-B2A24S20P BMS in a parallel configuration of 15S Configuration.

I've recently ran into an issue with the BMS, while discharging or even while idling, the BMS is displaying the error "Discharge MOS not normal".
The discharging of the BMS however seems to be normal, discharging with 100A from all the BMS without any issues and the BMS functioning as and decoupling in case of under voltage or over discharge.

However, when trying to charge the BMS, the charging MOSFETS seem to remain disabled and I am unable to charge the BMS.

I've attached the photos of one of the BMS' that's causing issues.

Would a damaged discharge MOSFET affect charging?
Anyone experienced anything similarly?
Would replacing the MOSFET be a solution instead of the entire BMS module?

My suspicion is that due to a large load on a couple solar chargers and inverters caused the mosfet to become damaged, as it sometimes enters in "short circuit" protection when trying to start the system.

Thank you guys,
Mihai

 

[byteharmony]

Just got the same error on my JKBMS

System turned off charging.

These are brand new, anyone have experience with their warranty?

 

[halvar100]

Just got the same error on my JKBMS

System turned off charging.

These are brand new, anyone have experience with their warranty?

Same issue I have.

 

[edavis72]

I had the same issue, forgot that I had reset the app and the "charge, discharge, balance was turned off in the app all the way to the right in the settings.

 

[OffGridIdaho]

Same here. Mine was the inverter inrush during re-power.

Shut down for 30 minutes to clean the inside of the inverter (dust)
Turned JK BMS back on and instantly get the short circuit protection fault.
Went into advanced password settings and turned off discharge slider in the bms.
SCP counts down from 60 seconds and doesnt blow another error.
Turned on discharge slider and BAM SCP blows again.
OK I think I have this figured out.

30 minutes down time was enough to drain the caps on the inverter (see where Im going?)
Turned slider for discharge off again. BMS reset to GTG at T MINUS 60 seconds and its happy.
Flipped main breaker to inverter OFF, turned slider inside jk bms to on or discharge again, no error.
Sooooo I took a small wire and ran it from the neg side of the battery (not other side of neg bms) to the neg terminal of inverter. FLASH-SPARK it starts charging caps slowly. Slow enough not to have a huge in-rush and trip SCP in the jk bms.
I wait 60 seconds and remove wire and re-touch, no spark. I quickly flip the breaker back on ito the inverter
AND HOLY FLEEPIN BATMAN it doesnt blow the SCP error.

It was the massive in-rush to the inverter caps blowing the SCP fuse inside the jk bms.