Sorry, but I have a problem with using an Optima battery in a W210. It does not have the vent tube connection. Now Optima says their battery will not gas in most conditions, but they did not say it won't gas at all. So under extreme charging conditions, there is still the possibility of a hydrogen buildup. Not something you want under your rear seat.

michakaveli - have you looked under the seat at the myriad of electronics under there? I think a spark might be possible. Combine that with a hydrogen cloud trapped under the seat, and the results could be nasty. That's why Mercedes put the vent tube in. I would get that battery out of there.

You guys might think I'm being alarmist, but why take a chance?

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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