Car model and year: 2016 Boxster S
replace the battery
Because the car had reached a ripe old age of 5 years and 6 months this week (late July 2015 build date for the car). ever so slightly slower crank speed when starting the engine cold.
What to do next?
Option 1. go to Porsche dealer
Called my favorite Porsche dealer. They wanted $416.95 including tax for just the battery and “$165 to $250” for labor “depending on what the car requires”.
Option 2. Buy a battery for $200 online first
Step 1. One of my favorite shop has one for $200 that appears to be an exact replica of the OEM battery, right down to the Ah rating and cold cranking amps. Same dimensions, same exact external physical features. So I buy it online and take my old battery over to compare it. Put it side-by-side and yes, it’s 100% identical including the 70 Ah rating and 760 CCA. Done.
Step 2. take the new battery to the Porsche dealer for “adaptation” the new battery.
Knowledgeable service advisor suggestion:
the battery adaptation procedure is only really necessary if you let the old battery get so bad you start getting warning messages and other weird behavior due to the various computers adjusting to the bad battery’s low voltage. He said various things will be shut down or put in low power consumption modes to conserve power and prioritize starting the engine on an old poor performing battery. In my case, I never had any odd behavior or messages, I just noticed some slightly slower cranking RPMs when doing a cold start. The battery adaptation procedure restores all the various computers and control algorithms back to normal operation with the new battery. Conclusion: If you install a new battery before you start having weird messages and behavior due to low voltage/power, the PIWIS battery installation/adaptation procedure is unnecessary.
Moreover, Basically if you change from stock agm to lead acid or vice versa then you need it programmed. also they recommend if the battery was super low to do it because as the battery gets older is changes its charging profile to adapt for that. and if a new battery is replaced it needs to “know” its new so it goes back. again it’s all up for debate whether or not its really needed. most likely it wont make a difference. at worst it comes down to maybe it not charging as efficiently as it should and causes you to wear out the new battery sooner.
My car is a late July 2015 build of a 2016 model year 981 Boxster S.
I’ve disconnected my battery at least a dozen times, almost all of those times for a minimum of a few hours, several times for days or weeks. I never used a backup power source. I have never had one single issue as a result. The only thing I do that is part of the WSM procedure for “after replacing battery” is to roll the power windows down, then within a few seconds press the down button again, then roll them up and after they are up pressing the up button again within a few seconds. This reestablishes the stop limits for the power windows. That’s it, never done anything else and have had no issues.
Option 4. Use Autel AP200 code reader for ~$59.99
My 2015 Cayman was on its original battery and lately had begun to show some odd behavior in cold weather despite being connected to a Porsche Charg-O-Mat most of its idle time during the last year. So, I decided to replace the battery. I bought a Duracell Platinum 94R AGM, 80h, from Batteries Plus and installed it myself. Interestingly, while the new one is a 94R (I.e., H7) like the old battery, the length of the Duracell is more like an H8. I kept the car connected to the tender through the footwell socket during the switch, though the battery was disconnected for just 10 minutes or so. I don’t think I lost any settings, but I reset the windows anyway. I immediately noticed much better Stop-Start capability and all of the electronics seem to be working as they should.
After a day, I bought the Autel AP200 scanner. I was able to use the reader to register the new battery.
Autel AP200 give me the option to change from lead-acid to AGM. The registration screen has entries for capacity, type (AGM. wet, etc.), serial number and Porsche part serial number. For the latter, I used a number I found online for a Porsche “OEM” 80ah battery.