For the heat pad, the bundle of green wires are the switched negative and the red & black aren't required. Connect heat pad to the green wires and to the battery postive.
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...
I've got this exact same issue (see: https://diysolarforum.com/threads/jk-4s-200a-bms-electrical-noise.45500/).
Appears to be a problem with the new 4-8S JK BMS as I don't have this issue with my 16S JK BMS. I also had issues charging with some power supplies.
I haven't found a solution and...
Did you ever resolve this issue?
I've having pretty much the exact same issue with 2 different 4S JK BMS's. See here:
https://diysolarforum.com/threads/jk-4s-200a-bms-electrical-noise.45500/
Its causing my BMV-712 to go crazy (swings in current measurement) when charging. I've temporarily...
I've got 2 early model (purchased in May) JK 4S BMS (JK-B2A8S20P) which are both creating electrical noise / interference only when charging.
I first noticed this with erratic current readings on my Victron BMV-712 Shunt which only occurred while charging and initially thought it was a faulty...
Any ETA on a release date?
I'm currently running a 16S 200A in my home ESS and it has been great. I'm building a couple of 4S systems for Car / 4WD fitouts and was going to use a JBD 4S 200A BMS, but would much prefer a 4S version of the JK BMS.
Is anyone having issues with the JK Android App on Android v12? I've just updated my phone to v12 and now the JK app instantly crashes as soon as it is opened. I've tried clearing the app data / cache and have the latest v4.0.0 build 33 of the app.
Another vote for Bluetooth support.
Can the UART module of the Overkill / JBD BMS be plugged directly into a Raspberry Pi or does it need an RS485 cable / adaptor?
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...