Battery Replacement for 997.2
05-10-2022, 12:45 AM
#1
Racer
Thread Starter
Battery Replacement for 997.2
Just did a search on this forum. Getting a bit of conflicting information so I was wondering if the battery size is different for the 997 vs the 997.2. The battery currently in my car is a MOLL Kamina 580 42. I assume the 42 is the BCI group? In searching this forum people have said that the replacement size is BCI group 94 (H7). This is the first time I'm changing the battery myself in this car so just getting familiar with this labeling system. Thanks.
05-10-2022, 02:13 AM
#2
Jaylin the 997.2 comes from the factory with an H7 battery (which is the euro size, and equivalent to the 94R group size). On our 997.2 we installed the much-improved AGM (absorbed glass mat) battery. And because I have a fear of ever being stranded with a dead battery, we upped the size to the larger H8 size. The battery tray and end clamp on your car have three attachment settings for an H6, H7, and an H8. The middle H7 engagement hole has a nut welded in place, if you move up to the H8 position you must provide a nut for the 8mm bolt.
AGM batteries have less internal resistance (faster recharge) and must not be charged at more than 14.8 volts. I have checked our car and, on a cold start-up, it will flirt with 14.8 volts, but after a few minutes it moves to a nice comfortable 14.3 float voltage.
This battery has been in service for about 6 years and we should get it tested soon, but it has never missed a beat. Whenever I have it on a battery maintainer it charges up to a full 12.84 volts (after removing the surface charge) same as when it was new.
AGM batteries have less internal resistance (faster recharge) and must not be charged at more than 14.8 volts. I have checked our car and, on a cold start-up, it will flirt with 14.8 volts, but after a few minutes it moves to a nice comfortable 14.3 float voltage.
This battery has been in service for about 6 years and we should get it tested soon, but it has never missed a beat. Whenever I have it on a battery maintainer it charges up to a full 12.84 volts (after removing the surface charge) same as when it was new.
The following 2 users liked this post by jennifer911:
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05-10-2022, 10:28 AM
#3
Rennlist Member
Goodness, @jennifer911 , that's about as complete a single answer as I've seen on this forum, and that's saying a lot! I've shied from AGM batteries in the past (though my Ford GT had one it came with) due to the inability to resurrect from a full discharge. Maybe I'm misinformed on that.
I've also heard goofy things about AGMs with trickle charging and jump-starting. (The latter becoming a practice we all do less frequently.) I guess these 'old school' concerns have kept me in the lead-acid world. Yet your advice sounds good enough to sway me. Thanks again.
I've also heard goofy things about AGMs with trickle charging and jump-starting. (The latter becoming a practice we all do less frequently.) I guess these 'old school' concerns have kept me in the lead-acid world. Yet your advice sounds good enough to sway me. Thanks again.
05-11-2022, 08:19 PM
#5
Racer
Thread Starter
Jaylin the 997.2 comes from the factory with an H7 battery (which is the euro size, and equivalent to the 94R group size). On our 997.2 we installed the much-improved AGM (absorbed glass mat) battery. And because I have a fear of ever being stranded with a dead battery, we upped the size to the larger H8 size. The battery tray and end clamp on your car have three attachment settings for an H6, H7, and an H8. The middle H7 engagement hole has a nut welded in place, if you move up to the H8 position you must provide a nut for the 8mm bolt.
AGM batteries have less internal resistance (faster recharge) and must not be charged at more than 14.8 volts. I have checked our car and, on a cold start-up, it will flirt with 14.8 volts, but after a few minutes it moves to a nice comfortable 14.3 float voltage.
This battery has been in service for about 6 years and we should get it tested soon, but it has never missed a beat. Whenever I have it on a battery maintainer it charges up to a full 12.84 volts (after removing the surface charge) same as when it was new.
AGM batteries have less internal resistance (faster recharge) and must not be charged at more than 14.8 volts. I have checked our car and, on a cold start-up, it will flirt with 14.8 volts, but after a few minutes it moves to a nice comfortable 14.3 float voltage.
This battery has been in service for about 6 years and we should get it tested soon, but it has never missed a beat. Whenever I have it on a battery maintainer it charges up to a full 12.84 volts (after removing the surface charge) same as when it was new.
Goodness, @jennifer911 , that's about as complete a single answer as I've seen on this forum, and that's saying a lot! I've shied from AGM batteries in the past (though my Ford GT had one it came with) due to the inability to resurrect from a full discharge. Maybe I'm misinformed on that.
I've also heard goofy things about AGMs with trickle charging and jump-starting. (The latter becoming a practice we all do less frequently.) I guess these 'old school' concerns have kept me in the lead-acid world. Yet your advice sounds good enough to sway me. Thanks again.
I've also heard goofy things about AGMs with trickle charging and jump-starting. (The latter becoming a practice we all do less frequently.) I guess these 'old school' concerns have kept me in the lead-acid world. Yet your advice sounds good enough to sway me. Thanks again.
05-12-2022, 01:36 AM
#6
Jalin, AMG batteries have been standard in most every car for the last 8 or 9 years, and they have no bad habits. Adam may have been referring to some of the older Optima batteries that are an unusual spiral wound design and had some quality problems.
An Absorbed Glass Mat (AMG) is still a lead-acid battery its only difference is that the electrolyte is absorbed into a mat and tightly pressed between the anode and cathode. Regular lead-acid has the electrolyte liquid splashing around covering the cathode& anode.
Do a quick internet search for all the advantages of AMG batteries. If you want the very best AMG ever made, look at the Odyssey brand, it is about 450 can$. However, no need for that kind of sticker shock, as every manufacturer has more thrifty priced models.
The safe choice is to stick with Porsche’s recommendation and go with a regular flooded cell battery. Although lots of people with 997.2 have made a switch over to AMG with no adjustments and had good results, but I’m no expert, so don’t go by me.
An Absorbed Glass Mat (AMG) is still a lead-acid battery its only difference is that the electrolyte is absorbed into a mat and tightly pressed between the anode and cathode. Regular lead-acid has the electrolyte liquid splashing around covering the cathode& anode.
Do a quick internet search for all the advantages of AMG batteries. If you want the very best AMG ever made, look at the Odyssey brand, it is about 450 can$. However, no need for that kind of sticker shock, as every manufacturer has more thrifty priced models.
The safe choice is to stick with Porsche’s recommendation and go with a regular flooded cell battery. Although lots of people with 997.2 have made a switch over to AMG with no adjustments and had good results, but I’m no expert, so don’t go by me.
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JayinToronto (05-12-2022)
05-12-2022, 01:57 AM
#7
Racer
Thread Starter
Jennifer911 thanks for the follow up info. That definitely clarifies things and solidifies my decision.
I just placed and order for the Napa Legend Premium AGM battery. Will install it tomorrow.
I just placed and order for the Napa Legend Premium AGM battery. Will install it tomorrow.
Last edited by JayinToronto; 05-12-2022 at 02:15 AM.
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