Battery recomendation please.

[86 911 Targa]

After only two years, and 1800 miles of service
the dealer/Porsche installed battery does not seem
to hold a charge after 24 hours of non-use.

1. The alternator is outputting 13.8V.

2. The battery shows 12.4 volts after 36hr 2A charge.

3. The static current draw test shows 20ma.

Any thoughts on a replacement battery?

I have used Sears in he past with no such issues.

Thanks in advance.

And best of holidays to all.

Gerry

[steely]

Hi Gerry -
Only 2 years is surprising/unfortunate.

I got an Optima Red Top battery (75/25) in 2011 - no real issues. It ran about $170 back then.
I do keep it on a minder in the winter.
This past summer I did not get to drive her as much as I used to and the battery was let down - I had a little trouble trying to get the cheap trickle charger to wake it up but I finally succeeded. Maybe I am getting close to needing a new one. I have gone a week or 2 recently w/o charging since that event.
Happy holidays to you too.

[offroader1006]

Interstate batteries is where I'd go. Any local shop should be able to get one.

2 years is way too soon for a dead battery. Definitely have it tested to see if it's a shorted plate. You should charge it and disconnect the battery for 24 hours and then see if it held it's charge.

[86 911 Targa]

I was advised by our local dealer:

1. If the car is driven less than 60 miles/day
and/or not placed on a "trickle" charger,
the battery will not be under warranty.

2. How this relates to "not holding" a charge
eludes me.

3. The Sears battery I previously had never
demonstrated these symptoms under the
same usage profile.

Have a look at the price for one of these
factory boat anchors.

[Cajundaddy]

I got 7 years from a Bosch battery in my 986. That was the longest life ever and probably a fluke. 5 yrs is typical.

[uwanna]

Whatever brand battery you buy, make sure to buy an AGM (absorbed glass mat) battery. They typically have close to twice the life of the old style flooded acid battery. Also AGM's can't leak acid and can be placed in most any position. I have used them for years. Initially more expensive but over the long run a better buy.
Check the comparisons between AGM and Lead Acid in this article:
https://carfromjapan.com/article/car-maintenance/best-car-battery-review/

[jlex]

I'd go along with uwanna's advice. Have installed AGM's in my BMW X3 & the Porsche and they both seem to be doing well. Make sure any charger you have can work with an AGM battery, though.... they're fussy in that regard.
Read about advance glass mat batteries on the 'net...
Actually, you may have to go with whatever battery they give you when you have them honor the warranty on the dealership battery. Two years is pathetically short and should be a warranty item.

[MBAtarga]

I just bought a replacement battery this week for my Targa. I got a group 49 AGM from a flaps (O'Reilly) for $185. Part number is 49PLTJ

[darrin]

I installed a group 48 agm battery in my '86 targa a few years ago and it's still going strong. The Group 48 size is a bit shorter (and lighter) than the Group 49 battery, making it easier to install/access. I have driven/started the car in sub-zero conditions several times and have never had an issue with the Group 48's slightly lower power rating. Significantly, our 911 battery trays are pre-drilled to hold both the Group 48 and Group 49 batteries, making the install of a group 48 battery a "turnkey" task (don't need to build/buy the adaptor necessary to retrofit in an optima)

[Koizumi]

Uuugh those 49s are always b*tch to install.

[kanadary]

Costco now sells interstate batteries. I got one last yr for the 911but have had them for my other cars. On the mdx the warrantee was a 42 month one and at 40 months the battery died. No questions asked. Brought it in and got a new one. Only charge was the difference in battery price from 3 yrs ago till now. Something like $5. Turned out it wasn’t the battery not holding a charge as the new one also drained in a week. It was the Bluetooth module circuit staying on, default position when the unit fail, go figure. So I spliced in another relay and all is fine I think I was charged about 110 or so for the battery and a $15 core charge

[steely]

Originally Posted by 86 911 Targa

I was advised by our local dealer:

1. If the car is driven less than 60 miles/day
and/or not placed on a "trickle" charger,
the battery will not be under warranty.

2. How this relates to "not holding" a charge
eludes me.

3. The Sears battery I previously had never
demonstrated these symptoms under the
same usage profile.

Have a look at the price for one of these
factory boat anchors.

Not that it matters at this point, but one of the battery warranty exclusions that is provided on one of the Porsche dealers sites (Suncoast for example) was that you used a maintainer if you drove less than 15 miles a day.

I did not see the 60 miles/day requirement - it seems quite high.

Out of curiosity, what type of battery is it? These days Porsche replacement batteries are AGM if I am not mistaken.

Optima states that maintained batteries can last 3x as long as a flooded battery (potentially up to 10 years)

[uwanna]

Originally Posted by steely

Optima states that maintained batteries can last 3x as long as a flooded battery (potentially up to 10 years)

I had an Optima Yellow top battery in my boat that was only used in the summer months. I kept on a maintainer during the off season and it indeed lasted a full nine years.
I have an O'Reilly AGM battery in my truck that I drive about once
a month, I check the battery voltage each time before I crank it up
and find the AGM stays at 12.5V or so over 4-5 weeks without a maintainer. AGMs are great!

[Steve@Rennsport]

I just replaced an Optima in my 911 that had been in service since 1999.

Pretty good value IMHO so I have no difficulty about recommending them with one caveat: these should be on an AGM-capable tender when not in daily use.

[sugarwood]

Duracell Ultra Platinum AGM Group 48 Battery

[SCadaddle]

A couple of years ago I replaced the monster Group 49 size battery that had gone bad with the smaller "near Group 48 size" battery from the local Autozone, otherwise known as a Duralast T6-DLG. It fit the factory spot in my 82SC like a glove and the hold down bolt/bracket fit the hole in the chassis just like it should. For what it's worth, the battery was made in Germany, I rarely drive my SC and let it sit in my garage for weeks or perhaps more than a month without any kind of trickle charger, and this battery spins the starter up to crank the car with authority.

You asked, that's my choice, and they are readily available.

[86 911 Targa]

Guess I'm hijacking my thread.

Any thoughts out there on the subject matter?

Never have used a maintenance free battery.

Thanks in advance,

Gerry

[Missed Approach]

Hi Gerry- Huge fan of the Bosch AGM S6585B- Group Size L3/48. Fits perfectly in the second (short battery length) screw hole and has the added safety benefit of Absorbent Glass Matt (AGM). As Summer generally takes place on a Tuesday up here, I have to pull the battery from Nov-April. I'm going on 4 years with this one, I just slap on the trickle charger occasionally during her downtime.

[darrin]

Gerry -- think the AGM battery (which is maintenance free) is the way to go for our 911s -- unlike flooded cell batteries, it truly is maintenance free - see, e.g. https://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

[WPOZZZ]

Originally Posted by sugarwood

Duracell Ultra Platinum AGM Group 48 Battery

That's what I get from Sam's Club. Put them in my BMWs and Porsches.