The battery on that board should last you at least 3 years if not longer. You can change it with the power on if your careful, just use a wood chop stick to pop it out then slide the new one in. Are you losing your program even after you've change the battery?

I haven't changed the batteries, it was my first time at the job. It happened on two different cars today, the building shut off the cars because of cavatation, there are multiple issues and i'm worried about losing programming during repairs.

A good way to determine if the battery is ok for you to turn off main line voltage is to open up the car station and use a meter to check the battery voltage. set on VDC, and place one lead on the ground connection of the CLC board, then look for the Diode a little above and to the left of the battery, it is D4 I believe, put your other meter lead on the anode of this diode, it should read 3 volts which is the voltage of a new battery. I usually see this around 2.7 volts and can turn off the power without reprogramming the CLC. I am not sure how low this can be before you lose the program, but i think above 2.5 should be fine. Just one last note, we obtained a dover contract a few years back with 8 dmc units, we lost the program on the first 2 cars we shut off for service, after investigating further I found that the D4 diode had been cut out from all the CLC boards on the job. sabotage

lol, had that one b4 also. There also is a transistor associated to that circut. Had some snip one leg off of it. very nasty

I've seen Thyssen sabotage equipment on jobs that they are losing in a similar way by using clear fingernail polish on the batter terminals.