That has been covered here before, it's not necessary to do so but it does slightly affect the charging rate to the battery.

IMHO, It's to get you, the customer, to go to a Porsche dealer to buy a battery for $ 500 rather than at Batteries Plus for $ 150.

 

Thanks for the info. I agree with you about pushing us to the dealer for a simple battery swap. Not happy about that, but it's Porsche's MO. Interestingly, the cost of a new OEM battery for my car is not unreasonable. I did a search online at my dealer's parts site and its discounted price is about $220. So I'll probably go OEM. My dealer, though, said I have a choice of them installing either a Porsche OEM battery or a less expensive Interstate battery. I was really surprised to hear this. But then I was told a battery replacement costs about $550 plus tax. That spells DIY to me. And to avoid the different charge rate issue, I'll install the identical OEM replacement. There actually are two OEM batteries spec'd for my car - either 70 or 80 amp-hour. Whatever my battery's capacity is (haven't lookedyet), I'll get the exact replacement and thus avoid any charge rate issue.

 

You have to go to the dealer to have it reset, so a DIY is not going to help you if you want it reset to a new battery, you have to pay to hookup to the dealer computer. Realistically, its a non-issue, my electrical engineer pal who works for Fiat-Chrysler in Detroit confirmed it. But if it makes you feel more comfortable....-

 

There are several tools available to enthusiasts that allow the battery to be reset. My iCarSoft POR V2.0 does it.

 

I did a battery replacement myself and kept power through OBD and I never needed to go to the dealer for programming - I think that is just something the dealer says to make money. I did have to do one thing and that was reprogram the automatic up and down of the windows which took about 2 minutes.

 

Guys, your help has been amazing and much appreciated. I'm going to pick up a battery and an iCarSoft POR V2.0 and do it myself. I'll save money, learn something along the way, manage to kill a few hours of this pandemic, and end up with a new tool as a bonus.

 

As I understand it, the charging rate is not so much the Ah rating of the battery but an internal clock that increases the charging output of the alternator as the battery ages. If you have it reset by the dealer, the clock starts over. I seriously doubt there is much difference, as the alternator is set up so it doesn’t overcharge the battery no matter its age.

 

You are correct... and there isn't a whole lot of difference in the profile.

For my two cents on this, as I deal with batteries specifically.... The larger manufacturers are making all parts that they can in a way that would require the dealership to service the cars. That is why they are making oil changes so hard and not caring so much about the location of the drains. That is why they are making the motors so untoucheable, and it even goes down into batteries. Now keep in mind I'm not a conspiracy theorist, and there are benefits to doing some of the stuff they do. But yes they WANT to force you to go to the dealer as much as possible, and they want to have complete control on the warranty issues and all aspects of the Cars.

The fact is they have these very elaborate computer and CAN communications systems to review the battery voltage and type of charging that goes to the battery nowadays.... but the fact is on newer batteries you WON"T get the 10 years that might have happened in the past, now its basically 2 to 4 years of life for a Lead Battery. Its a sort of built-in obsolecesnce of the battery for sure, becuase the fact is they could make a battery that lasted longer and a charging system that keeps it perfect... but they make it complex to keep you going to them and keep it lasting a shorter period of time so you have to buy a new batteryevery few years. And the largest Lead Battery Manufacturers have dumbed down the batteries and made the plates thinner in effort to keep the turnover going, but that is typical of most products nowadays.... the sales won't hold up if they make products last long. These Cell Phones are evidence of that... battery goes dead like clockwork every 2 years... you get a new expensive phone, or they update so you can't go back. They could easily make one that last 4 years or more with a changeable battery as some do... but Apple won't they want you to buy a new phone each two years..

The newer communication systems do tell the car the status of the battery and the assists with the smart alternator with the Intelligent battery sensors to charge the battery less, and only charge during decelerations, therefore providing less drag on the motor ... so that is great and they do have to meet EPA standards and mileage standards so this type of system is very beneficial... but it certainly is NOT providing for longer battery life which it could do. Also its getting worse in the future for modern Porsches because the latest Porsches that do come with Lithium Batteries will have proprietary Porsche Lithium Batteries with a proprietary CANbus protocol that only works in Porsches, its the same with McLaren and will be with others. So even though the McLaren Battery and Porsche Battery will look the same and both be made by A123 System, they will not be interchangeable..... So that will end the ability for you to simply replace the battery in your Porsche in the future.... and that is getting crazy because the McLaren Batteries are like $3k to $4K just for the replacement, and its hard to get them outside of the McLaren network. So soon this window will close and if you get a newer Porsche you will ONLY be able to get you Porsche Battery from a Porsche Dealer making the easiest product to replace on your car basically impossible to replace without paying a crazy cost for it.. And I can tell you $3k to $4K for a Lithium Battery is absolutely un-realistic, but they will have you by the purse strings.

 

If the day should ever come when changing a battery must happen at the dealer for an outrageous cost, that’ll be the day I never keep a car past it’s warranty end date.

 

Which makes the dealer even happier

 

The dealer and OEM will be grinning ear to ear selling you another new car lol.

The real solution is to buy slightly older cars that you can actually service yourself.

This is the reason I bought a PIWIS 2 clone from china, I can do anything the dealer can now to my car.

 

Meh, someone will figure out how to crack that code, its just electronics and software. I'd not worry too much about it. The McLaren guys won't care, they make their money so quickly they'll just pay it rather than be bothered by it.

But the cheapass Porsche guys will figure it out. <g>

 

LOL. Most probably true, and it will be posted here!

 

I just bought an iCarSoft POR V2.0 to diagnose my 2013 991's battery's condition, as I believe the nearly 7 year-old battery's to blame for some weird stuff going on with the car (front radiator fans keep starting up full-blast a few minutes after shutdown for no apparent reason). Below is the battery report the iCarSoft produced. Even though the car cranks well and starts right up, I'm wondering if the highlighted portions confirm it's time to replace the battery. Note also the battery voltage of 12.15v (same as the instrument cluster was reporting) and open-circuit voltage of 12.4v, both of which seem low. The car was last driven yesterday on the highway, and the report was run with the car "on" but the engine was not started. If anyone has any thoughts about this, I’d appreciate the help. Thanks.

 

yeah - I think your battery is heading down. Battery curve that I received recently with a new AGM battery for my race car shows open voltage of 12.8 - 12.9 V for full charge, and 12.5 for about 50% charged.