Optima Battery venting?

[oletrux]

OK, I know the hazards, so I'm asking for a little history. Do you guys vent your Optima batteries when they are located inside the car or just tie 'em down? Optima recommends venting, which entails adding a box, and I wonder if it is their lawyers that insist on that. It is my understanding that these batteries do not gas unless subjected to high charge rates, but I'm certainly no expert. Thoughts, experience??
Thanks.

[4dFord/SC]

Found this on the Optima Battery site:

"When used with a properly regulated constant voltage charging system (such as an alternator), the OPTIMA will not emit hydrogen gas. However, gassing can occur when charging at excessive voltage levels or in extreme high-temperature conditions. In automotive applications, this typically will not happen if the alternator/regulator stays below 15 volts."

The 15 volt comment obviously refers to the 12 volt version.

I've used a Red Top for 14 years inside a Group 2 disguise case mounted in the battery tray, and the only gas problems that I recall were passenger-related.

[1948F-1Pickup]

^ Pretty much what he said.
It must take a lot of overcharging to get those valves on the top of the Optima to "pop." The top of the Optima in my '48 is wavy..... Before I fixed it I think the alternator was putting out about (14.5 and more) to accomplish that feat. Obviously the vents didn't vent......

[G.M.]

The problem with Optima's is they are not vented. The gas
stays in an air space above the cells. There is a vent valve that
opens if the gas pressure builds up. This gas eats the thin lead
connections from the cells to the battery terminals causing a very
weak connection. The connection may be enough for ignition but
not good enough to run the starter. I cut several that failed apart
and could see the problem. G.M.

[ford38v8]

Always multiple answers to every question, here's mine:
I had a 6V Red Top inside a Ford script battery case, (sealed on top, open on the bottom). On a road trip, my Voltage Regulator malfunctioned, overcharging the battery to the point that I could smell the acid inside the car. (My '38's battery box is under the hood). The voltmeter confirmed that it was continuing to charge long after it should have leveled out.

I stopped, disconnected the regulator & generator, and ran the car from the battery alone, hung a U-Turn back to an old Auto Electric shop that luckily had a new regulator. Installed the regulator and continued the trip without further problems. That Red Top lasted me another 3 years after that incident!

[JSeery]

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Originally Posted by 1948F-1Pickup

^ Pretty much what he said.
It must take a lot of overcharging to get those valves on the top of the Optima to "pop." The top of the Optima in my '48 is wavy..... Before I fixed it I think the alternator was putting out about (14.5 and more) to accomplish that feat. Obviously the vents didn't vent......

14.5 volts would be the normal output for an alternator in a 12v system. That is not an indication on any issues other than normal 12v system normal output. All this assumes you have a 12v system to begin with!

[1948F-1Pickup]

Originally Posted by G.M.

The problem with Optima's is they are not vented. The gas
stays in an air space above the cells. There is a vent valve that
opens if the gas pressure builds up. This gas eats the thin lead
connections from the cells to the battery terminals causing a very
weak connection. The connection may be enough for ignition but
not good enough to run the starter. I cut several that failed apart
and could see the problem. G.M.

Have any photos of these autopsies? I'm thinking that would be a long time before these connections would get eaten away.