Optima Battery

[OptimaJim]

I mention the venting provisions, because it is the technically correct way to install a battery (yellowtop D34/78 batteries do not have vent tube provisions). David is correct- under normal operating conditions an AGM battery will not vent gas. However, all lead-acid batteries can vent gas. Since alternators or chargers can fail, the safest and correct mounting method for trunks and passenger compartments is to make sure that any possible gas venting will escape to the outside of the vehicle. All vehicles with original equipment battery locations in trunks or passenger compartments will have a vent provision that should be used.

Although people do it anyway, we cannot recommend installing an unvented battery in any enclosed space, because there’s a legitimate, albeit unlikely, safety risk involved.

For example, IF there is a voltage regulator failure, and IF the battery is severely overcharged, and IF this goes unnoticed, and IF the battery vents because the internal pressure exceeds the release pressure of the vents, the gasses are both flammable and toxic. This may sound like a lot of “ifs,” but attorneys and engineers get paid to plan for every worst-case scenario.

Jim McIlvaine
eCare Manager, optima Batteries, Inc.
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