Battery Vent Cap Adapters

There are several situations where a Battery Vent Cap Adapter may be needed. The reasons for replacing your original battery vent cap with a different one may include:

1) The original vent cap is broken or lost, and you need a replacement battery cap.
2) You want to replace the original cap with a red, yellow, or white vent cap.
3) The original vent cap does not contain a flame arrestor, and you want to replace it with one that does.
4) The original vent cap is too short which causes the top of the battery to get wet when the electrolyte overflows on occasion. A taller vent cap helps to prevent that.
5) The original vent cap allows the electrolyte to evaporate too quickly, and you want to replace it with a Water Miser cap so that you don’t need to add water as often.
6) You want to check the electrolyte level without removing the vent cap, so you want to replace it with a level indicator that needs an adapter to fit your battery.

Whether the original vent caps on your battery are screw-in (threaded) or push-in, we manufacture a battery vent cap adapter that will retrofit any quarter-turn bayonet vent cap to your battery. To purchase, just click on any adapter picture below to enter our online store.

Note- the items listed on this page are adapters only. The battery cap itself is not included and must be purchased separately. Click here to view our battery caps.

Battery Vent Cap Adapter #4D-8D-SIA

  • Fits 4D or 8D Batteries with Screw-in Caps
  • Converts 3/4″ Diameter Threaded Hole to Accept 1/4-turn Bayonet Caps
  • Screw-in Style with Rubber Seal (Included)

Click here to view this item in the online store.

Battery Vent Cap Adapter #4D-8D-PIA

  • Fits 4D or 8D Batteries with Push-in Caps
  • Converts 3/4" Diameter Hole to Accept 1/4-turn Bayonet Caps
  • Push-in Style (No seal required)
  • Fits All Batteries with 3/4 Inch Diameter Vent Holes

Dress up your car's engine compartment! This adapter lets you replace the original plate style cap that covers all three holes with our yellow, red, or white battery caps. The adapter fits 3/4 inch diameter vent holes, please measure your battery before ordering. Click here to view this item in the online store.

Battery Vent Cap Adapter #M22X1.5

  • Converts M22x1.5 Threaded Hole to Accept 1/4-turn Bayonet Caps
  • Screw-in Style with Rubber O-ring Seal (Included)

Click here to view this item in the online store.

Battery Vent Cap Adapter #M27X3-SIA

  • Converts M27x3 Threaded Hole to Accept 1/4-turn Bayonet Caps
  • Screw-in Style with Rubber Seal (Included)

Click here to view this item in the online store.

Battery Vent Cap Adapter #1050VCA

  • Fits European Push-in Style Batteries
  • Fits some Batteries Manufactured by Douglas Battery Co.
  • Converts 1-3/8" Diameter Hole to Accept 1/4-turn Bayonet Caps
  • Push-in Style with Rubber O-ring Seal (Included)

Click here to view this item in the online store.