Hi there, any tips on getting a battery for my 85 308 (euro GTS if relevant)? It had an old/dead Interstate MT-34R and the San Diego Interstate warehouse says that battery is no longer available. They suggested I look at a Group 48? I did check the owners manual briefly but didn't see a specification for the battery size. Pic for reference. Thanks Mike Image Unavailable, Please Login
So it looks like I can get the AGM version of 34R from Amazon - not sure I really need an AGM but let me know your thoughts on which battery. Thanks Image Unavailable, Please Login
Interstate Megatrons are excellent. I used to sell them in my shop. They would send a truck once a month over to stop by and replace sold inventory, rotate batteries, check the status, etc. If I needed a group I didn't have they would deliver by truck in a few hours. Never had a problem at all.
Just go to NAPA and get a 34r Legend. It will last for 15 years. https://www.napaonline.com/en/p/BAT7534R?
Don't poo poo the battery I recommended.. I researched the AGM one and found that is made by East Penn (very good company here in USA) and probably makes some of the top tier batteries mentioned here The price is great so is the battery I have suggested to many here and so far no complaints
Keep in mind that while the AGM batteries work, the output of the alternator is not at the optimal level for an AGM, ie. AGM's charge at a somewhat higher voltage. The conventional flooded batteries are what the car was designed for, and you will get the max cranking power from a flooded battery.
I use the same Duracell on my 308 GT4. Peeled off the Duracell stickers and put on a Magneti Marelli sticker (because I'm a nerd). Image Unavailable, Please Login
There are only 3 major battery makers in the US so chances are, no mater which brand you buy, they are all the same on the inside. And some brand names are actually manufactured by several of the makers.
Got that through Killmanjaro Designs, here's the link: https://kilimanjarodesigns.com/product/20-1-magneti-marelli/
Costco sells Interstate Group 34, $115. Just went through that. As previously noted the alternator will not support an AGM battery.
What you usually find at contract manufactures is something like the molded case is standard but they offer options to change the internals. Lead is expensive so when you look at the different "grades" at the autoparts places the cheaper versions are almost always lighter, often much lighter. They mess with the size and thickness of the plates to hit output and life targets.....so you can usually find the better battery of any particular size by just looking for the heaviest one. For a sports car though, its hard to want the heaviest battery......I usually do the opposite and look at the lowest cranking amps I think I can live with and buy the lightest, which I know means it has the smallest, thinnest plates and probably the shortest life but in my head I'm believing the 5-10 lbs weight saving actually matters to car performance
To close the loop here, I picked up a NAPA legend Group 34R (thanks johnk...) Price came in at 199, and it fit perfectly using the factory retaining plate (that clams the bottom of the battery). Thanks to all for your input! Mike Image Unavailable, Please Login
