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1997 993 Optima Battery to Vent or not to Vent, Part I and II

Electrical and Electronic

Vehicle Information: Model: 993; Year: 1997; Body Type: Coupe; Total Mileage: 34,000;

Joel,I recently reviewed the many items on battery replacement in 993s; after cleaning out, priming and repainting my trunk floor subsequent to acid leakage,(the prior owner had not attached the vent/overflow after battery replacement). Having had prior experience with Optima gel batteries, I ordered the Optima 34R (the +/- posts are reversed), used the base adaptor supplied and re-radiused the factory cast + cable end. It fit great. I spoke with Optima Tec and they "assured" me that no venting of the battery is necessary, since the unit will only gas if the internal core temp exceeds 124 degrees, at that point it will blow out the two top vent caps. I will let you know if I have any problems. Stephen (SCG C2) [PART TWO - received as a second "question" / followup]Joel, just when I thought I had the final answer to the Optima battery question of gas venting, I received this e-mail, after I spoke with them on the phone. Re: whether or not we need to vent these batteries. This is the response I recieved from Tom at Optima to my question.SCG C2Good question and concern. The 34R has two pop up release valves that will pop up and vent the "cooked" AGM paste if the internal core battery temperature reaches a certain degree and stays at that temp. for a sustained period. For safety and liability purposes, I recommend that you somehow attach a vent tube (to my knowledge, Optima does not make anything specific for this type of application) to that top area that covers both release valves in a sealed manner, so if they do pop up and release, the battery will vent properly. The issue here though is to somehow cover that area in a completely sealed manner, not interfere with the release valves and such.Is it necessary? Hard for me to say one way or the other. Hope this helps.Regards,Tom1st Optima Battery

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