This battery vent cap is designed differently and costs slightly more than our standard vent cap, but it provides peace of mind. Due to the fact that all lead-acid batteries produce a flammable gas, a flame arrestor is an important option. Hence if a nearby spark ignites the gas, the internal spark arrestor stops the flame from entering the battery where it could ignite the internal gas. You can also learn more about this battery vent cap by reading this.
This battery cap will fit on all batteries that have a standard 1/4-turn bayonet vent opening. Several adapters are also available that allow you to retrofit this vent cap to most other batteries. If your battery needs a screw-in or push-in type vent cap, choose from the threaded and push-in type adapters that are listed below.
Screw-in battery cap adapters:
#4D-8D-SIA Adapter (7/8 inch diameter threads) Fits 4D and 8D batteries.
#SE2218 Adapter (M22x1.5 metric threads)
#M27x3-SIA Adapter (M27x3 metric threads) Fits Enersys Varta battery.
Push-in battery cap adapters:
#4D-8D-PIA Adapter (Presses into 3/4 inch diameter hole.) Fits 4D and 8D batteries, or any battery with a 3/4″ diameter vent hole.
#1050VCA Adapter (Pushes into 1-3/8 inch diameter hole.) Fits European style DIN battery.