I have 3 different battery back up with surge protectors running on different circuits in my office. Several times per day they will all (at the same time)start beeping back and forth from battery power to regular power. They will do this from anywhere to just a couple of minutes to an hour and then will quit. I have our city electric dept stumped at this point. Any suggestions from BR?

I normally replace the batteries when that happens on the UPS's at the hospital.  But.....

    3 different units doing the same thing would eleminate the inside battery being bad on all three units at the same time. 

Are the 3 units tied on the same breaker?   Would appear to be.   ??????   

   IF so, then maybe.....

   Large shredders, copier and laser copiers  or larger appliances on the same circuit have been known to be the culprits when it comes to tripping UPS's. 

   

All 3 are on separate breakers, and have been in this current config for several years with no problems.  We must be getting periods of low or high voltage that is setting them off.  I have the city guy coming back to put on a voltage recorder today.

Thanks

Just a suggestion, have you talked to other businesses in town that maybe expierincing the same things at the same times.

     Electric provider could be snowballing you and already know they have grid problems during peak times.