danglerb

I think I got 3 or 4 replacements out of that Pepboys Bosch (hecho y Mexico) 36/84 warranty, last one is sitting in my garage on a trickle charger because the Duralast Gold I was sure was dead, took a full charge and refused to die.

Same warranty and much cheaper price for the top battery at Walmart, so if I wasn't locked into the prorated warranty I would consider one of those.

GTASHARK

Interstate is a safe bet, or Optima Red Top 35.

Maleficio

Optima will fit the 928 battery bay?

JPTL

Answer

hacker-pschorr

The Interstate batteries in my two 928's and my wife's car are going on 8+ years.

Every winter they sit on an Interstate brand maintainer (re-badged battery tender).

The Interstate in my mothers Jaguar just died after 9 years.

Maleficio

jeff spahn

Bosch for me. Sits on a tender all winter.

borland

Always buy on 'me too' recomendations. Don't trust buying on cold cranking amp-hour ratings, fitment, or warranty. Don't read the owner's manual to find out what the factory recommends for a replacement. Those facts can be very risky. Also, don't worry, be happy.

GregBBRD

I love threads like this...."What battery do you have in your car?" Is there anyone , out there, that feels that they were stupid and purchased the wrong battery? Human nature eliminates people from thinking they were foolish.

No. Optima does not fit. You will need to fabricate a "safe" mount.

People that are "less" safety oriented just stick them in the hole and close the door. Some of those idiots may even stick a block of wood in the hole, to help keep it from moving about. Build a mount that will hold the battery in place, even if the car is on its roof....anything less is stupid.

928s are, generally, not everyday drivers today. That makes the Optima battery line very attractive, since these batteries seem to not "die" from discharging and then recovering, as bad as some brands.

Bosch, from my experience, seems to be the worst, for this. They seem to "need" to be maintained at full charge....at all times. Run it down once and it may never recover. Two times and you probably need a new battery. Porsche "replacement" batteries run a close "second" to Bosch for this problem. The original Porsche batteries that come with the car are different and do not suffer as badly from this problem.

I don't think I've ever seen a "Sears" battery that didn't leak/seap and make an incredible mess. (In all fairness, I haven't bought one, in years....and hopefully, they have improved. Back when we did a ton of 911 work, a Sears battery simply meant that you needed a new carpet set for your front trunk...should have been included with the instructions.)

If you want a battery that will "bolt in" and work, hard to beat the Duralast line from Auto Zone. They don't generally leak, hold charge, have good warranty, easy to obtain, etc.

I've heard that the Interstate Line is of good quality. From a business standpoint, I can't use this company. They "need" a shop to stock and have inventory of their product....which isn't a huge deal, if you sell a fair amount of batteries. We don't do much "service" work, these days, so we don't sell many batteries. Having a "rack" full of batteries sitting around gathering dust makes no sense....even though they might maintain them and "switch" them out. It simply makes no sense for either Interstate or me....I simply do not have a large enough "volume" to do business with them.

Walmart....I have no idea of what they have....I'm trying to imagine me walking into a Walmart store and explaining that I need to buy something "without sales tax" added in, so that I can sell it to a customer collect the tax, from them. I don't see this happening, so I'm guessing that I'd end up paying "double' sales tax on every battery. Taxed when I buy it and taxed when the state collects the taxes from me, on things I've "resold". That's not going to work....loose 9% on every battery you sell....can I make that up in volume?

For my shop...it's pretty easy. The "best" is an Optima. It's going to cost you as much for me to fabricate a mount as the battery costs...so that is a pretty expensive battery....but they are very good. Everyone else gets a Duralast.

928mac

What Greg Said ^^^^

And just to safe I put a 1/8" heavy rubber mat cut to the shape of the box on top because it is very close to the lid and if it happens to come loose you dont want it to make contact with any metal.

JPTL

With a little modification for the cables to route, you can actually use the plastic shipping cover that comes with the Red Top as a clean looking and capable insulator.

JHowell37

I use an autocraft which is the same as a duralast, only autocraft is sold by advance auto. My first one lasted 4 1/2 years. Since I buy a lot of stuff from that store, they took care of me when I got a replacement last december. They didn't charge me for it. There is one thing I noticed. When I got the original about 5 years ago, it was a different battery then what they sell for the '85 now. It also costs about $50 more. The battery I bought 5 years ago is still available. Both have the same dimensions and post orientation. The one the catalog now recommends is easy to spot. It's usually them most expensive one on the shelf. Like I said, when you see that one, look for another one that's the same size. It should be there, and it will work just fine. The only bonus to the more expensive battery are the built in handles to pull it out of the hole.

Tom in Austin

Do 928 batteries last longer, all else being equal, because they're not in an engine compartment?

hacker-pschorr

Only 5lbs, why not get one of these?

http://lithiumpros.com/products/performance-street/

Tom's 87 928 S4

Unless they have greatly improved them, Optimas are junk. Been through 4-5 in 2 years. Once they go down, they are toast. Only Interstate for me from now on.