Mike Dolt Enterprises
Mike Dolt Enterprises
User: dmsdrome, Location: Central Valley in CA
Asked on: Monday, April 18, 2011 at 4:51 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:20 am EDT
Question: Are there minimum space requirements for charging lead-acid batteries because of off-gassing during charging? The equipment being charged is a ride-on floor cleaning machine with (4) 12v batteries being recharged overnight in a 10'x10'x8'H closet.
Yes, lead-acid batteries produce hydrogen gas during charging, so there should be adequate ventilation to prevent accumulation. The National Fire Protection Association (NFPA) 70, the National Electrical Code (NEC), states that the space should have a minimum volume of
1 cubic foot per ampere-hour of battery capacity
OR1 cubic foot per 20 pounds of battery weight
For example, if your ride-on floor cleaning machine has (4) 12v batteries with a capacity of 100 amp-hours each and a weight of 25 pounds each, the minimum required space for charging would be: Volume per battery: 1 cubic foot per 100 amp-hours = 1 cubic foot Volume per battery: 1 cubic foot per 25 pounds = 1.25 cubic feetUsing the larger of the two calculations, the total minimum volume required is 1.25 cubic feet per battery x 4 batteries = 5 cubic feet.Since your closet is 10'x10'x8'H, it has a volume of 800 cubic feet, which is well above the minimum requirement of 5 cubic feet.
Therefore, the closet you are using to charge the lead-acid batteries is adequate in size and meets the ventilation requirements. Flag for review