Car Battery Vent Tube — Why batteries have vent tubes All lead acid batteries create hydrogen gas when they’re being charged. Older flooded lead acid batteries (non-maintenance free) used a vented cap above each cell to vent hydrogen and water vapor from each cell during charging. That why those older batteries required occasionally topping off with distilled water. Maintenance free batteries, on the other hand don’t freely vent charging gases and water out of the battery. First, they have a different plate construction that doesn’t create quite as much hydrogen … Read More
The post Car Battery Vent Tube appeared first on Ricks Free Auto Repair Advice.

