Did you know that sulfuric acid (H2SO4) based batteries produce Hydrogen (H2) when charging?
This is why OSHA requires ventilation (1910.178(g)(2) and “NO SMOKING” signs (1910.178(g)(10) in charging areas.
And FYI… H2 is 16X’s lighter than air, so the exhaust needs to be in the roof- not even high up on the wall near the roof – the ROOF. And please use an intrinsically safe fan system rated for Class 1, Div 1, Group B HAZLOC.
If you’re charging PIT batteries, you have a HAZLOC, even a Class 1, Div1, Group B HAZLOC. You can use a properly designed, operated, and maintained ventilation system to lower the area from a Div 1 to Div 2, when you can show the ventilation will ensure the area never reaches 25% of H2 LEL, which is 4% or 40,000 ppm. 25% of this is 1% or 10,000 ppm.
This incident involved 30, 100 lb. batteries used as a power backup for MRI.