EG4 LL-S Dead BMS

So after months of back and forth with EG4 on here (spoke with EG4_Jarrett back in December/January and EG4_Jared last month) and no luck getting them to send me the right 232 cable to update the BMS on my 4 LL-s and 4 PowerPros, I decided to try another Amazon 232 cable (photo below). At first it seemed like it was working. Got connection to the battery, opened the updater, loaded the .hex file, opened com-port, clicked update and then....

"Initialization failed, please check BMS connection

Clear Flash failed, Please Update again"

Tried a couple more times, closed com-port, disconnected the cable and then no more BMS. Won't light up. Won't turn on. Nothing. So now I sit with a $1500 brick.

Any thoughts or suggestions?

The EG4 RS232 cable has this pinout:


The Amazon listing cable looks like it has this pinout (below the image):

Not the same pinout, but hopefully it didn't cause damage to the device.
Should be possible to make a converter for your cable so it matches the pinout of the EG4 cable.

Thanks for the response. Unfortunately for me, I have no clue how to read that diagram or make a converter to use whatever pinouts those are supposed to be. That's why I've been waiting 6 months for EG4 to send me one.

On a positive note, I was just informed that a cable arrived at my other address today so maybe they finally came through, even though it was supposed to be sent here (I installed systems at two different addresses). Guess I'll pick it up this weekend and bring it back down the hill.

So it's possible that installing the firmware with the correct cable could bring it back to life?

Have you tried powering off the BMS with the switch (giving it around 10 seconds for any capacitors to discharge) and powering it back on?
I can't find the pinout of the battery comm RJ45 port to know if the +,- RS232 voltages might have damaged anything.

Yeah. Tried that. Left it off for a long while and still nothing when I push the button. Blank screen and no SOC lights.

Unfortunately you appear to have soft bricked the BMS. They can be recovered in the field but it is a fairly advanced process. You really need to get with the higher ups at EG4 to get a good technician to help you through this one.

The RS232 cable shows to be delivered yesterday, and I apologize for the delay in shipping. I suggest attempting to reapply the RS232 update without any communication cables connected, ensuring the use of the correct cable received. Should this fail, please DM me with the number of batteries that were bricked and a photo of the serial number(s).

Yes, the cable was received. Thank you.

I'll grab it this weekend and bring it back down the hill with me when I return. I won't try updating the PowerPros up there until I successfully update the LL's down here.