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
Harvey Hadden Sports Village has opened today following a £16m transformation.
Sunny spells and showers, feeling cool in a northerly breeze.
Scattered, locally heavy showers. A cool northerly breeze.