50 firefighters are tackling a blaze at G&P Batteries on Willenhall Road, Walsall.
ITV News Central has been told by eyewitnesses that a number of loud explosions could be heard at the plant.
It is the second time this year a fire has broken out at the factory - the previous one on 14 January saw 60 firefighters in attendance.
More top news
Mostly dry although rather cloudy.
Often cloudy with patchy rain today. Clearer and chilly tonight.
We start October on a mild, sunny note but will it continue?! Find out here....