JPP

Costco has a replacement as well, made by Interstate. Reasonable, easy and a $5 core rebate on your old battery when you bring it back in ...

IXLR8

My late model 2003 and 2004 BMW motorcycles supposedly came with an OEM GEL battery. I got a pitiful 5 years tops out of them, whereas the FLA BMW Mareg batteries in my older airhead BMW motorcycles would fail in the 9th year. So I'm paying more to get less. Go figure!

Thats usually the case on forums. You need to know enough to know what is good info and bad info.

Van1

I dunno, I bought my 993 almost 8 years ago and it had a newish looking Optima red top in it (Judging by the part number it was a Costco special). Just went and started the car for the first time this season and that same 8 year old Optima is still going. Car started right up on the first try. Of course, I use a Battery Tender during the off months. My next battery will be another Optima, if I can ever kill this one.

IXLR8

Here is a list that I put together of Group 48 and 91 batteries for our 993s.

The difference between the two groups is the height of the battery and Ah. The group 48 that Porsche has been selling for the 993 requires that the plastic trim panel be either shaved slightly or bent over the top of the battery.

dryadsdad

We'll look at that too. Thx.

dryadsdad

Thx for the chart. 5 years is reasonable life for a bike battery. I tend to think them suspect after 4. My BMW bought new in 2007 got 4 batteries replaced under warranty - they'd go dead suddenly. One died while really in the middle of nowhere. I had to abandon the bike to get to a place to call for a pickup.

Turns out the batteries were defective. BMW eventually replaced the Exides with a Yuasa.

911Dave

The point is they don't need maintenance. They have emergency venting only, in the event of overheating. They do not leak acid or corrosive gas like standard lead acid batteries do. The disadvantage with those is that electrolyte levels must be maintained. Why bother with that when you don't have to with a sealed battery?

I've been using an Optima Red Top for 8 years and it still operates like new.

IXLR8

And thats the beauty of them; you can.

Problem with the AGMs, if they do gas, your battery will lead a shorted life. And they can gas. Remember, charge voltage required is based on temperature.

Well a load and capacity test is the only way to tell.

Dave, you're doing well and there is no reason that battery can't last double that. The trouble with AGM or GEL batteries is that the charging method is more critical. They shouldn't be overcharged and they do not like ripple. The local buyer rep for Costco up here used to carry them. There were too many returns.

BTW, I purposely overcharge my regular battery from time to time to equalize the cells. I can afford to do that...all I need to do is add distilled water...can't do that with a sealed battery.

But whatever works for the owner.

IXLR8

Yup, that is what it was, an Exide.

In fact, I believe the battery in my 1995 BMW coupe was an Exide as well.

I think they have issues with quality control.

BTW, the original battery that lasted 18 years (lost track of the new owner after that) and my present 13 year old daily driver are made by Panasonic in Japan. Luck? I think quality control has a lot to do with it, provided the car's charging system is up to snuff.

DanL993

Now that's what I'm talkin'. I never recode the radio...that engine is enough music for me!!

Allen

The last battery I installed in my '97 993 was a Sears DieHard International Series...don't know part number, but it is a 72 month battery. That was on 2/25/2002. The battery is still in the car...and has a battery maintainer on it any time it's not being driven. As a "test"...I let the car sit without the maintainer for (3) weeks...just to be sure all was OK. It cranked right up. So when I decide to replace this battery...I guess I'll get another DieHard. As a side note...I have a "Battery Mat" underneath my battery. It is suppose to absorb any leaks, spills, etc. I check the arae from time to time...all is fine, but I like having the Battery mat there.

Allen

These cars have a radio...??!!?

H.H.Chinn

+1 for the Optima red top battery. They're lightweight, don't need to be maintained and won't ever leak. It's too bad that Costco discontinued carrying them, however O'Reily's I believe now stocks them. The one in my car must be at least six or seven years old now.

IXLR8

Same here. I have one in my 993, but its the only car that I've ever used one in.

They are advertized to "neutralize" acid, not just absorb acid. I have yet to have any of my batteries leak in 35+ years but since I had it lying around from a previous car I never used it in, it went into the 993 as an underpad.

NC TRACKRAT

As stated in a previous thread, Sam's Club is now carrying East Penn batteries under the "DURACELL" trademark.