911pirate

I am at the point I need to replace my battery in the 99, 996 cab. I am trying to decide which way to go. Several people told me interstate MTP91 ($150.00) others say OP red top ($189.00)...others say stay original (part #99961108020) ($210.00) not sure original is worth the money not sure what mods are need for the other choices. I can buy a new Porsche brand battery part # 99961108820 but not sure, it will fit. Any advice, especially regarding the 99961108820?

maci911

autozone or pepboys....

Marc Gelefsky

I have always done well with Interstate in my Porsche's. Used the MTP91, also have one in my wife car. The "Porsche" batteries I have been told to avoid.

jhbrennan

The Interstate will fit and can be secured. The Optima Red Top will need a special bracket to hold it in place. If you go Interstate make sure you get the right model - I think the MTP91 is correct but verify the dimensions.

Van

Mine lasted 10 years (it's been getting weak this winter - and finally crapped out this morning).

deckman

I got a new one at Sears for $135. Diehard Group 48. I don't remember all the specifications, but am sure it has higher ratings than the Porsche battery.

Phil G.

You DON'T want me to respond to this thread. Believe me.

Marc Gelefsky

Why would YOU need a battery?

Marc Gelefsky

The last Interstate in my 86 lasted 9 years!

ivangene

OMG that's funny on many levels!

jhbrennan

Were you able to anchor the battery to the tray?

smackboy1

Here's a link to my Optima install about 2 years ago

https://rennlist.com/forums/996-foru...a-battery.html

Yellow Dog sells a plastic or aluminum mounting plate. FWIW I like my Optima, pretty much problem free. I did have a battery draining issue but it had nothing to do with the Optima. Turned out to be the interior lights.

Another option for even more weight savings is an Odyssey battery.

4Scargo

Just bought a 49-1 from Wally world...$69! Bought a battery tender w/float from Harbor Frieght $8(?) Been accused of being cheap, but I prefer frugal...afterall I own a Porsche with money I've saved

Van

Having just taken my battery out, I can tell you that there are several "mounting spots" for the bolt-down bracket. This should mean that you can use a battery of a different length - as long as the terminals are on the right sides.

aviatorX

By all means, DO NOT waste your money on a Porsche battery. I have made that mistake in the past. The last one made it less than 2 years! Yes, I use a battery maintainer.

I recommend the Interstate Battery #MTP-H7. This is the DIRECT replacement in terms of size and location of the vent hose attachment point. You will NOT need the vent hose adapter kit. It uses one of the existing clamp points on the battery tray. It's an 800 amp (640CCA) battery compared to the stock Porsche's 380. The engine turns over much faster then before.

It also comes with an 85 month no-questions asked warranty. The Porsche one does not.

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