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Note that batteries+ also has the group 48 battery which is the original size. I went with the Size 49 for my 991.1 but since this is just a warm weather car not sure this was the right decision. I know 11 lbs won’t make a difference, but just doesn’t look optimal.
Edit just looked at MFG code on the battery. It is a year old. Going to return it....
Last edited by bsix; 09-01-2020 at 09:09 PM.
Reason: Old battery
Saved this thread since buying my 2012 C2S 3 months ago. Finally bought an Energizer AGM H8 yesterday to replace the >8yr old original battery. I can finally stop worrying about forgetting to plug in the charger, and can stop keeping the booster battery pack in the car now. Thank you @daberlin !
Observation - I have the CTEK eyelet on the positive terminal and the chassis. Plugged in the MXS 5.0 during the swap. The charger had stage 4 lit (14.7V, declining current) by the time I disconnected the terminals. Things were fine at first, but after a minute, I can hear a an audible ticking sound to the driver side of the battery in the frunk, and I can see an amber slow flashing light front of the car. Got new battery connected asap and things returned to normal. Took it for a drive and things were fine. Not worried, but no idea what caused that...
Successfully replaced original battery from my 2013 991.
- Original battery: > 7 years. Was still functioning. Idle mind is a devil's workshop. Itching to do something.
- Original battery : part# 999.611.070.10 / 12v 70Ah 760A EN /AGM
- Replaced with Interstate battery from COSTCO: MTX-49/H8 95Ah 900A. Yes, 10+ pounds more and bigger than the original.
" connected to 12v socket under glove compartment. I know, two schools of thought. But I didn't want any settings to be lost nor have issues with memory settings buttons (had issues with Cayenne). After the swap, it did retain all the settings. Car did beep/click when the old battery was disconnected, until the new battery was re-connected (it was strange)
" to register/code the new battery. This worked for me, trick was to use Porsche battery part# 95861109221 , same specs as MTX-49/H8. In-addition, when entering, drop the first digit of the Interstate battery scanner code. I believe these are all from VARTA
New battery supposed to make any difference in driving experience? Seems a bit chirpy now or is it all in the head?
I'm ready to replace my battery. I've been through the thread, but just want to make sure that 2 good options are the Duracell Ultra Platinum with 48 month warranty or the Interstate MT-49 with 24 month warranty?
I'm ready to replace my battery. I've been through the thread, but just want to make sure that 2 good options are the Duracell Ultra Platinum with 48 month warranty or the Interstate MT-49 with 24 month warranty?
what’s the cost and what is the amp-hr rating? I replaced my 6-7 yr old 991.1 c2s battery with an OEM battery from my dealer. Cost was $210 and it’s an 80 amp-hr battery (original was 70 Ah but those are discontinued). Though the Porsche battery came in a Porsche box, it didn’t say Porsche on it. It said VW, and it was larger than the old battery (the tray in the car is adjustable). You will need to “register” the battery in the car’s electronics, and for that you need only provide the Ah rating and a s/n. Easy to do with OEM, and you can reuse your old battery s/n (I believe) if you get non-OEM. Bottom line - I’d buy OEM if the cost isn’t out of line. It shouldn’t be. Wasn’t for me (batteries are heavily discounted on dealer parts web pages).
Looks like the Duracell 92 AH, It's $210 at Batteries Plus. Reading thru the whole chain most people have said you don't have to do anything registering the battery with the electronics.
I'm sorry if this has already been answered and this is obviously an amateur question, but where do you plug your batter tender in that allows you to disconnect the vehicle battery with no adverse effect on the vehicle's electronics? In the center console cigarette lighter plug or down by the passenger footwell?
I'm sorry if this has already been answered and this is obviously an amateur question, but where do you plug your batter tender in that allows you to disconnect the vehicle battery with no adverse effect on the vehicle's electronics? In the center console cigarette lighter plug or down by the passenger footwell?
It was always my understanding that one should NOT connect a powered charger to the electrical system with a battery removed. Connecting a backup battery should be fine.
I'm sorry if this has already been answered and this is obviously an amateur question, but where do you plug your batter tender in that allows you to disconnect the vehicle battery with no adverse effect on the vehicle's electronics? In the center console cigarette lighter plug or down by the passenger footwell?
On my 2014, I plugged in to (as I always do) the cigarette lighter, did the battery swap, and all was A-OK. Just about 12 months ago this week.
I'm sorry if this has already been answered and this is obviously an amateur question, but where do you plug your batter tender in that allows you to disconnect the vehicle battery with no adverse effect on the vehicle's electronics? In the center console cigarette lighter plug or down by the passenger footwell?
There is no need to connect a backup power supply while changing the battery. None.
Just use the regular precautions applicable to typical battery replacement and you will be fine.
There is no need to connect a backup power supply while changing the battery. None.
Just use the regular precautions applicable to typical battery replacement and you will be fine.
I had both of my Mercedes batteries (main and auxiliary) disconnected for about a week and all of the radio/GPS settings remained. Same experience on a BMW when changing a battery.
Looks like the Duracell 92 AH, It's $210 at Batteries Plus. Reading thru the whole chain most people have said you don't have to do anything registering the battery with the electronics.
Actually, what most people said is only partly true. It seems to be true that you do not have to register the battery with the electronics. Peoples' cars seem to work even without doing that. However, Porsche's SIT publication for the 991.1 says the following (emphasis added): "In the event of battery replacement, the gateway (master control unit in the battery/energy management system) must be informed of the battery manufacturer, capacity, serial number and part number with the PIWIS Tester II under the path Maintenance/Repair/Battery replacement. This resets the maps used to calculate the battery condition." I suspect metadata like battery manufacturer and serial number, etc. are not necessary for the map reset function to work as designed, but battery capacity (Ah-rating) surely must be. The iCarSoft diagnostic reader (latest version) will allow you to do this if you don't want to take your car to the dealer. It truly takes all of 5 minutes to do, and most of that time is spent finding where to plug the iCarsoft in under the dash. I'm a fan of doing what the factory says should be done, and the SIT manual in this case says "must" be done. Whether "must" here really means "must" or something less, like "should" or whatever, I don't know. Maybe it's not necessary at all, as others have said. But Porsche says to do it, and it's simple to do. So why not do it?
BTW, on a related topic, most people on the forum have said it's OK to jump your battery by connecting the jump starter leads directly to the battery's terminals. And in fact, I've always jumped a car that way myself on my other cars. But I also have seen it said never to do that on the 991.1. So which is it? Porsche's point of view on this issue is, again, in the SIT manual, which expressly warns not to do that. Instead of coupling to the negative battery terminal directly you should connect the jump starter's negative lead to the negative body ground terminal situated and marked about a foot to the right of the battery. Why? Because the SIT manual says: "Every external charging/jump starting operation on the battery must be performed at the jump start terminal at the positive battery terminal and the corresponding ground terminal (marked in the engine compartment). The negative battery terminal must not be used for external charging/jump starting since the battery sensor can be destroyed by voltage peaks during the charging operation/jump starting." Will the car jump start by coupling leads directly to the battery? Yes, it will. Will the battery sensor always be destroyed if you do that? No (I personally can vouch for that). But it might be. So, irrespective of what others say, the better practice would seem to be to listen to what Porsche says about this to avoid a possible problem in addition to a dead battery.
06-26-2020, 05:26 PM
