It's unclear what they want with them, but thieves have swiped 25 backup batteries from cell towers in southern Ontario in a week, police say.

Const. Max Gomez of Middlesex County Ontario Provincial Police said he's heard of thieves stealing copper wire or metal, but the batteries are new.

"Our officers do attend to some calls where maybe car batteries have been taken, and those are then taken by culprits who then recycle them," he told CBC News.

"I don't know why these people would be stealing the batteries. I suppose there's some monetary benefit to them but no, I don't think they're lighting up their lights and their iPads with these batteries."

Three tower break-ins

There were two reports of cellphone tower sites being broken into on Aug. 24.

Police in Middlesex County say backup batteries in cellphone towers - similar to these ones - have been stolen from a tower in Middlesex Centre. A second theft and a third attempted theft took place in neighbouring Oxford County. (OPP) An alarm went off at 2 p.m. at a Bell Canada tower on Curry Road in South-West Oxford Township. A technician went to the site at 6 p.m. and discovered someone had broken into the fenced-in site — removing the lock on the gate — and disconnected 16 batteries.

The batteries were lined up at the door, which had been propped open. Police suspect the thieves planned to return later to pick up the batteries.

On the same day at 3 p.m., an alarm went off at a Rogers tower on Clark Road, just north of the 401, also in South-West Oxford Township.

No one went to check on the tower until a routine maintenance check on Monday, police said.

In that case, the culprits removed two locks to access the fenced-in area, pried open the door and removed nine batteries.

Then on Monday, a tower site on Adelaide Street North in Middlesex Centre was broken into. In this case, the fence was cut and tools were used to gain entry into the building. Once inside, 16 PowerSafe sealed lead 12-volt batteries were taken.

Police say the culprits broke into the fenced-in area at the tower sites, including this one in South-West Oxford Township as seen in a 2015 image taken by Google StreetView. They would either cut locks or through the fence itself to gain access to the small building, which houses the batteries. (Google StreetView) The batteries cost approximately $10,000 each to replace.

Batteries prevent dead spots

Gomez said the big problem with stealing the backup batteries is that they're needed if there's a blackout to keep the towers operational.

"In case of a power outage, these batteries ensure that mobile communication clients, they stay connected to family and friends and to emergency services if need be," he said.

In a city, it might not be a huge concern if one tower goes down because other towers may be able to pick up the slack, but in rural areas, there are fewer towers.

"In the case of a power outage, if these batteries are not present, that will create a dead spot in that area," he said.

Police are asking metal recyclers and electrical disposal businesses to keep an eye out for the batteries and to contact police if someone brings them in.