DR911s

The OEM battery in my 2017 C2S when "tested" using my iCarsoft POR 3 scan tool indicates that it now has 59 Ah capacity. New rating was 80 Ah. No issues thus far. When not in use, whether in home garage or off site storage garage, it's on a battery maintenance charger. At home it's on a Porsche brand charger which is a CTEK unit labeled as Porsche, and when in off site storage, on a CTEK charger. I've found that the Porsche branded charger is not suitable for off-site storage because if/when there is any electrical power grid supply interruption, that charger will not reset and resume its charging/maintenance duty; it has to be manually reset. In contrast, the CTEK charger that I purchased at Amazon does automatically reset to the same setup that was manually set when first plugged in... it has a memory.

Given that I just experienced a 12 year old flooded acid H9 size OEM battery fail in my 2011 Audi S4 after working flawlessly just the day before, and that everything in the Porsche is electromechanical or computer controlled, I'm planning to change the Porsche battery before this winter. It's now about 7 years old. I will probably go to Walmart to buy a new H7 size AGM.

First991C2

I replaced my old Banner today with an Interstate AGM from Costco for $169. Although I’m not sure I needed to. I put the battery charger on it when I was done and it said charging 62%. I did not expect that on a new battery. That’s what my old one said after the car sat a couple of days.

CEbbott

I’ve got 2.5 years on a lithium Antigravity and it’s been perfect. Bought it as a replacement for the original in my 2013 C4s. Decided that it was the cheapest way to save 30 pounds of weight and now Love being able to check its health via an app.

B Russ

Is it H6 or H7 for 2017 4S

First991C2

I put an H8 in my 2012. It was much larger than the old one and it maxed out the battery tray.

B Russ

So people, what is it H6 or H7 for a 17 4s?

rensoyka

don't remember what the original was but dealer replaced it with H8. any one of the 3 sizes will fit the tray, depends on how much power you want and how much you want to spend.

NiteJav

2018, still on the original knock on wood, I do keep it on a tender if not using it for a week or more.

Cityfisher

My 2017 lasted until mid 2022

polobai

I used a h6 replacement (antigravity) for my 991.2 (2018 carerra t). You can use h6,7 or 8 as there are provisions for all 3 sizes.

HK G36C

Exactly 5 years!

Speed2k

2017 C4S still on original battery, so far so good.

Big Swole

My 2017 TTS had the original battery (48 week of 2016) and I just had to replace it.

I've used a CTEK during my 3+ years of ownership.

RSflared72e

Just had to replace the battery on my 2018 base at 20k miles. Other factors: the car has lived its whole life in Arizona and the Las Vegas area. No recent battery tender use.

DBH

Same here. Also spends most of the winter in a nice warm garage on the Battery Tender.