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."