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Just an FYI on programming the new Duracell Ultra Platinum AGM battery into the car:
The dealer is going to do this Monday at a total cost of ... ugh... $106. I checked with the nearby Indy and they wanted the hour minimum $120.
I wasn't going to bother, but then I saw the voltage readout in the car hit 15 volts on my second outing after installation so I figure the ECU is now confused. It has never read beyond mid-14s before. It's been just a little lower but still going into the high 14s since then. I guess I'm willing to cough up the $100+ for the piece of mind that I'm not toasting the new battery.
I'll post another update after I see what the new charging behavior is once it is reprogrammed.
The reason I opted for the Duracell battery was due to the warranty. Not that the $100 ECU flash is all that big of a deal, but even IF there was premature battery wear due to ECU data, say for argument sake the battery dies in 2 years, then unbolt that sucker and take it back for a new battery.
This weekend I’ll check voltage readings as well since I’m curious too.
Did you have the CTEK set in the power supply mode?
Yes, I used my CTEK 7002 device. I used the pigtail with the ring connectors because the alligator clips would not hold firmly. I will describe the method used at the final stage before disconnecting and removing the old battery.
1. Connect the Red ring from the pigtail lead to the position battery terminal using a second 10mm nut that will fit the threads and tighten firmly (Not too tight).
2. Connect the black ring from the pigtail lead to the nearest ground on the chassis. I used the adjacent strut lug next to the air filter housing. You will need to use a nut that will fit the excess threads and tighten firmly (Not too tight).
3. Connect the CTEK battery lead to the pigtail. (AT THIS TIME DO NOT PUG THE CTEK DEVICE TO THE 120 V OUTLET)
4. Verify your wiring connections are correct. ONCE VERIFIED - POWER UP YOUR CTEK 7002 DEVICE.
5. Using the [MODE] button depress it until the [SUPPLY] light illuminates.
6. Proceed to loosen 10mm nut and remove/detach NEGATIVE terminal from battery.
7. Proceed to loosen 10mm nut and remove/detach POSITIVE terminal from battery. (Use a micro-cloth or latex glove to wrap around positive terminal connector to prevent grounding to chassis.
8. Clean battery tray if required, and reconnect connectors to new battery in reverse order.
9. Once both connections are completed, power down the CTEK device and disconnect the pigtail.
10. Secure battery with the hardware.
CTEK 7002 - Supply Mode
Two Ring Pigtail - Red Landed Positive Lead & Black to Chassis ground
Just an FYI on programming the new Duracell Ultra Platinum AGM battery into the car:
The dealer is going to do this Monday at a total cost of ... ugh... $106. I checked with the nearby Indy and they wanted the hour minimum $120.
I wasn't going to bother, but then I saw the voltage readout in the car hit 15 volts on my second outing after installation so I figure the ECU is now confused. It has never read beyond mid-14s before. It's been just a little lower but still going into the high 14s since then. I guess I'm willing to cough up the $100+ for the piece of mind that I'm not toasting the new battery.
I'll post another update after I see what the new charging behavior is once it is reprogrammed.
Just a FYI. The charging voltage is temperature compensated, at least that's my observation in my 991. Batteries require more voltage at lower temperature. With the recent cold snaps here in Austin I've seen 15 volts. The CTEK chargers increase voltage on the snowflake setting.
Yes, I used my CTEK 7002 device. I used the pigtail with the ring connectors because the alligator clips would not hold firmly. I will describe the method used at the final stage before disconnecting and removing the old battery.
5. Using the [MODE] button depress it until the [SUPPLY] light illuminates.
CTEK 7002 - Supply Mode
Thanks. I have the CTEK 7002 also. I was uncertain that it was safe to use the Supply Mode on the car and no damage would occur to the cars electronics.
Latex glove wrapped over [Positive Battery Connector]
Originally Posted by PTGFAR
Thanks. I have the CTEK 7002 also. I was uncertain that it was safe to use the Supply Mode on the car and no damage would occur to the cars electronics.
PTGFAR, just follow my instructions and you will be fine. By applying [supply voltage] to the car you’re just paralleling the (CTEK 7002 with the Battery).
This is similar to jump starting your car (Batteries are connected in parallel), but in this case (car battery & CTEK 7002).
Make sure you wrap the postive connector with latex gloves and/or micro cloth towels after removing the battery to mitigate an accidental short to ground.
NO DAMAGE to car’s electronics if you follow my instructions.
Good luck! If you need my help just send me a PM
Last edited by Sidvicious7; 01-12-2018 at 11:34 PM.
The reason I opted for the Duracell battery was due to the warranty. Not that the $100 ECU flash is all that big of a deal, but even IF there was premature battery wear due to ECU data, say for argument sake the battery dies in 2 years, then unbolt that sucker and take it back for a new battery.
This weekend I’ll check voltage readings as well since I’m curious too.
Great thought... but now I'm curious as to whether I'll see charging level changes after the ECU update. I guess at this point I'll be the guinea pig even though I have to pay to play. It may be money down the drain but now my curiosity has the best of me.
Originally Posted by sdl2112
Just a FYI. The charging voltage is temperature compensated, at least that's my observation in my 991. Batteries require more voltage at lower temperature. With the recent cold snaps here in Austin I've seen 15 volts. The CTEK chargers increase voltage on the snowflake setting.
That's a really interesting observation! I happen to know that the temperature the morning I saw the 15v reading was in the mid-high 40's. I was trying to decide whether to join some folks for a sporting Hill Country drive on that Saturday after the hard freeze earlier in the week, so I was checking the temperatures before I went out. I haven't seen 15 again, but then I've only been out when it was a bit warmer.
Any recent new battery changers have similar high battery voltage numbers like storm?
High charging voltages are normal for AGM batteries. Ambient temperature is a large factor; they want to be charged at higher voltages when cold, and the ECU will crank up the voltage accordingly. I wouldn't be concerned about 15V, as long as it's not in the red zone on the gauge.
I would be curious to hear if the charging behavior at the same temperature remains the same after the new battery is 'coded' by the dealer. The service manual doesn't shed much light on what's really happening, and rest assured, the dealer techs don't know anything we don't.
Just an FYI on programming the new Duracell Ultra Platinum AGM battery into the car:
The dealer is going to do this Monday at a total cost of ... ugh... $106. I checked with the nearby Indy and they wanted the hour minimum $120....I'll post another update after I see what the new charging behavior is once it is reprogrammed.
Follow-up after visiting the dealer...starting with the bottom line: There appears to be no need to go to the dealer to get a reset done, especially if you don't use the OEM battery.
The good news was the Austin dealership didn't charge me anything. After hooking up the PIWI's and looking at the battery, they determined that they are unable to do the proper PIWIs battery reset since I used a non-Porsche battery. Apparently there is a serial number and code they scan off of Porsche batteries required to do the full battery reset. While they were at it though, they cleared a couple of codes that were probably due to the previous weak battery. But the service advisor doesn't think being unable to do the full reset is a big deal at all and thinks this battery will be just fine.
So here are my observations of the charging behavior before and after. I don't know if a "proper" reset would have changed anything, but after my visit I'm seeing no differences.
During my test drive before going into the dealer this morning I noticed something I'd never noticed before. I decided to let the car get fully warmed up before going in so I could check battery behavior at normal operating temperatures. I went out on an open road and watched the charge levels using the MFD gauge. The battery voltage was showing between 13.7 and 13.9 volts. I was surprised since I had been observing high 14s. Wondering what had changed, I realized I wouldn't normally still be in Normal mode. Since it was a cold morning (for Texas) I had stayed in Normal mode for longer than usual.
So I pressed Sport and within a few seconds the voltage rose and stayed between 14.7 and 14.8 volts. I went back to Normal mode and it quickly dropped back down to the high 13s. I did this several times and the voltages rose or dropped each time. At first I thought maybe it was due to RPM differences since Normal was shifting to 7th and Sport to 6th, so I went to manual shift mode and found that the reading wasn't being influenced by RPMs at all (at highway speeds at least). It was still lower in Normal and higher in either Sport mode.
It seems that in Normal mode the car is reducing the load on the alternator to get better gas mileage for improved EPA ratings. I already knew the engine temperature stayed higher in Normal mode than Sport in non-performance driving but didn't know about this one. Oddly enough after stopping for some eats, restarting the car, and driving the last stretch back home, the voltage behavior changed again and stayed at 14.8 volts regardless of which mode I was in. Just when I thought I had it figured out! Oh well.
The other FYI is that one of the things that caused me to go ahead and change the battery was I had started getting a warning symbol that AutoStop/Start was being disabled, I assume due to low battery levels. Even though I don't use this feature the warning was still appearing. It was the final straw that made me decide to go ahead and get a new battery. This cleared up right after the battery change by itself and isn't happening any more. I enabled Auto Start/Stop this morning and tried it a few times. It seems quite robust... but enough of that! Off the button goes again.
StormRune, I too have seen the same voltage fluctuations on the MFD (before & After) the Battery exchange. This is normal, and expect to see the voltage readings in the high 14s. During my startup in the morning (high 50s or low 60s) my voltage displays at 12.5 V, but when I’m driving her in normal mode the voltage will fluctuate just as you described. What prompted me to replace my battery was that it was taking longer for the battery to charge to 100% and the age (4 years old). The new battery charges to 100% within 1-2 hours. As for your comment quoting the Porsche Tech I must add I was not surprised. I was hoping to hear some revelation on why the cars requires programming. You just confirmed what was shared with me when I spoke with a Porsche Tech last week.... “They check for error codes and reset fault codes that do not require repairs.”
PTGFAR, just follow my instructions and you will be fine. By applying [supply voltage] to the car you’re just paralleling the (CTEK 7002 with the Battery).
This is similar to jump starting your car (Batteries are connected in parallel), but in this case (car battery & CTEK 7002).
It's actually better than jump starting your car, because the CTEK is less likely to feed your car a voltage spike, which is the main cause of electronics failures when jump starting. I had forgotten about "supply" mode on the CTEK 7002, which I also use for extended non-operation periods. Good tip!
01-12-2018, 07:34 AM
