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I was having some odd electrical issues (charging voltage showing 14.5 to 15.0, no start/stop, rear door not unlocking) and was curious as to when the battery had been replaced on my recently acquired 2011 S and pulled the battery today. Date code on the negative terminal was 1210 - week 12 of 2010 - the original battery! Since it's out I plan on replacing, but odd thing is it starts like a charm.
There is a How old is your battery thread in the 987-981 forum I started. My 09 has a 44th week, 2011 battery which has never given a week crank or other bad symptoms. Always had the car on a tender when not used. The threads on how to open the frunk with a dead battery are scary. I still haven't moved my emergency frunk cable to the side mark light area. Car is for sale.
I was having some odd electrical issues (charging voltage showing 14.5 to 15.0, no start/stop, rear door not unlocking) and was curious as to when the battery had been replaced on my recently acquired 2011 S and pulled the battery today. Date code on the negative terminal was 1210 - week 12 of 2010 - the original battery! Since it's out I plan on replacing, but odd thing is it starts like a charm.
For grins, ask them to run a test on the battery. Similiar thing happened on my 911. Battery was 8 years old still going strong. Was getting antsy. So I replaced it and when they tested it, it was was worn out. It wasn't suffering from a hard fail, it was just worn. Had about 1/4 of its CCA left.
I have a Solar battery tester that showed 342 amps after charging at a rated 850 and a failed diagnosis. After I charged the new Advance H8 AGM battery it showed 939 amps at a rated 900. Hope this gets rid of some gremlins
I bought a new to me 11CS about 2 months ago. I have done all the normal fluid changes and such. About 2 weeks ago I had an issue where the headlights kept cycling on and off throughout the night, with the key out of the ignition. In the morning I disconnected the battery terminal and let it sit all day. That evening I hooked the battery back up, and no more issue with the lights. I checked the battery for amps when starting the vehicle and they dropped to like 10.xx, but it started. I decided to get a new battery. When I removed the battery it was stalled 4310. Must have been the original. It had always started strong but in glad I replaced it.
My cayenne apparently has the original 2013 battery according to the Porsche dealership that sold me the vehicle. I have zero issues however I do need to test it to find out remaining battery life. I keep mine on a Porsche battery maintainer as well. Testing it is the best option versus guessing on remaining battery life.
If you have Launch you can also read what the BMU thinks the wear level is of the battery, along with the internal impedance and current chemical state of charge. I read mine out after replacing a battery in another car that died just sitting due to COVID. I am probably going to change my cayenne battery proactively based on this wear reading, although it has never failed to start without issue even after sitting for a few months.
I looked at my battery readings and I am at 64% charge acceptance rate, 76% battery charge after driving and being on the Porsche AGM maintainer. I guess my 2013 battery is at it’s end of life!
I am headed over to Porsche tomorrow to pickup a new battery.
Mine is reading 72% charge related, 87% output related, 89% charge condition. It’s the original battery in a 2011. I’m thinking it’s not ready to be replaced.
I'm not sure how they're calculating it, so this is entirely speculation unless someone knows what BMU they have, but if it's like other BMUs I've worked with:
battery ageing charge related is likely something like (current charge capacity)/(design charge capacity) so possibly what the BMU thinks the remaining full charge capacity of the battery is in amp-hours over the design capacity on the second page (mine said it thought the battery was 92 amp-hours, probably defaults?).
battery ageing output related is probably something like (max(current over some time window)) / (design max current), but I'm guessing there. They probably monitor current during crank or something?
internal resistance is a much longer discussion, but usually tracks with age (cycles) and temperature, although I'm not familiar with what values for this mean in an AGM battery. I bet they are calculating this watching open circuit voltage vs known (measured) load voltage, hence the current sense readings.
charge condition I think is self explanatory, what the BMU thinks the current chemical state of charge of the battery is. I have no idea if they try to charge to 100% or try to stay at some other value to preserve battery life.
On the other pages I also saw they take (or model?) the temperature of the pack and the connectors, kind of interesting, probably this is how they choose when to back off of charging and the voltage on the gauge moves down, at least mine does (from 14.4 down to ~13V after long drives).
Looks like mine is the most worn/aged battery out there so far, not really surprised. My auto start stop I always have turned off, but when I do turn it on just to try, it seems to disable itself and the engine starts after just a few cycles. I always assumed that was because voltage was dropping too quickly due to the load.
I looked at my battery readings and I am at 64% charge acceptance rate, 76% battery charge after driving and being on the Porsche AGM maintainer. I guess my 2013 battery is at it’s end of life!
I am headed over to Porsche tomorrow to pickup a new battery.
Great thread!
I just replaced my battery. Porsche wanted $360 for the proper battery for my 2010 997/.2S. I found the same battery at NTB for $180.
purchased the Interstate battery at NTB and had Porsche install and program for the new battery.
03-10-2020, 07:03 PM
Oldest Original Battery?
