More than 600 batteries have been stolen from trucks and machinery across South Auckland in the past four months, police say.
In some cases 20 to 30 batteries, worth $300 to $400 each, have been stolen in one overnight burglary spree.
Counties Manukau central area prevention manager Inspector Bruce O'Brien said sometimes significant damage is caused accessing the batteries.
"Trucks or machinery often need a lot of expensive repair due to the way the batteries have been ripped out and stolen," he said.
"Sometimes fences are cut through and a significant amount of damage is being done to access these batteries. It is affecting these businesses and we are acting with urgency to find out who is stealing and trading these items."
It's suspected the batteries are being broken down for scrap or being sold through an underground market.
"We are working in partnership with scrap metal dealers throughout the district to ensure that the stolen batteries are not sold through that market space. However we are looking to the community to assist us with any information they have about the trade of stolen property."
Police are also increasing patrols through the Wiri industrial area.
Burglars are also targeting residential properties looking lawnmowers and garden and power tools, and police advised residents to make sure gates and sheds were kept locked.
Owners of trucks and commercial vehicles should distinctly mark batteries, lawnmowers or any other valuable item with names or company logos.
Last week police searched a Manurewa address, and located $8000 worth of stolen property which was returned to businesses.
A woman has since appeared in the Manukau District Court on charges of receiving stolen property.
Police said anyone with information on truck batteries or other stolen property should contact Counties Manukau Police on 09 261 1300, or contact Crimestoppers anonymously on 0800 555 111.