MD3820i controller/battery "removed" with error 5E 22

I have an old MD3820i that has lost one of its controller modules. It is out of warranty, so I am trying to limp it along until funding for its replacement opens up. I'm hoping someone recognizes the errors I'm seeing.

We have experienced other battery failures on this model, so I naively assumed when I saw the "RAID Controller Module Removed" and "Removed Battery Module" messages in MDSM that I would be able to replace the battery, use the serial port to reset the clock and battery age, and everything would work normally again just like the last time. Not so.

On the back of the troublesome controller, I see an amber battery light and error code "5E 22". The rest of the lights are green. All of these lights were the the same before and after the replacement, as were the MDSM messages. I have not been able to figure out what the error code is supposed to mean, and I have not been able to initiate a serial connection to get more information from the management port. I tested my serial cable on another controller with the same firmware, so that part at least should work.

Am I missing something obvious here? Is this thing just toast? Any help or ideas are appreciated.