Rick's Free Auto Repair Advice

Car battery venting

Battery venting

Why battery venting is needed

All car batteries can vent hydrogen gas under certain circumstances. When the battery is located under the hood, it simply vents the gas into the underhood compartment and normal air movement disperses it.

But when the battery is located in a closed compartment inside the vehicle or in the trunk, it must be vented to the outside to prevent a buildup of potentially explosive gasses.

How battery venting is done

Vented batteries come with a port on each side of the top of the battery case. One of the ports is plugged, and the other side is open. That’s because some cars’ vent tube is on the left, while other are on the right. Simply attach the vent tube to the proper side of the battery and use the plug on the opposite side.

vented car battery

WARNING: Never install an unvented battery in an interior passenger or trunk compartment

Even a sealed top battery can still vent hydrogen gas in extreme discharge/recharge events.

©, 2021 Rick Muscoplat

Posted on by Rick Muscoplat


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