MERIDIAN OPTION 81C DC POWER - BAD BATTERIES

AC DC switches are totally different. you really can not change one over to AC without changing out a lot of hardware, if you can even get the hardware now. And it wont be cheap.
As long as the battery banks are in parallel, it will run fine on one bank. What is the voltage of the "good" bank of batteries?
Also the switch doesn't need batteries to run. It can run fine straight off the rectifier. Just hope you don't have any power issues.

THANKS FOR THE RESPONSE, THE VOLTAGE IS CLOSE TO ZERO FOR BOTH BANKS.
AFTER DOING A BIT MORE READING I SEE NOW THAT THE BATTERIES AREN'T NECESSARY
FOR THE SYSTEM TO RUN AND SINCE THEY REALLY DON'T PROVIDE MORE THAN
5-10 MINUTES OF BACKUP THEY CAN BE REMOVED.

I HAVE BATTERY COMPANY COMING OUT TO LOOK AT THE CONFIG AS I'M NOT SURE HOW TO
REMOVE BATTERY CONNECTION. AS I SAID, NO CLEAR ON/OFF OR SEPARATION OF SERVICE FROM
BATTERY TO RECTIFIER. IN MIKE'S COOKBOOK, I FOUND BATTERY BANKS CONNECTED TO PBX
BUT IT HAD CLEAR ON/OFF FOR THE BATTERY CONNECTION; IN THAT SCENARIO THE BANKS OF
BATTERIES CAN BE WORKED ON WITHOUT TURNING THE PBX OFF.

I SHOULD KNOW MORE ON FRIDAY AFTER THE SURVEY.

AGAIN, THANKS FOR YOUR TIME.

You can run it without any batteries at all. If installed properly there should be a disconnect between the batteries and rectifier shelf.