991.1 Battery Replacement DIY
#378
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These are different standards and usually based on the country where the battery comes from. That does not mean it might not have a CCA (SAE) as well on a European battery.
EN = European Norm
DIN = Deutsches Institut für Normung (German Institute for Standardization)
Each standard tests a fully charged battery to different voltage levels for different load time periods. You can find conversion charts that convert SAE, EN, DIN, JIS, IEC standards.
#379
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And just switching to an AGM is not why your voltage dropped.
Source: East Penn Technical Manual
![](https://cimg5.ibsrv.net/gimg/rennlist.com-vbulletin/755x510/i_9tnmnj9_o_1b75f47776d636043110a3629c60601a5ec7231e.jpg)
Spot on for a charge voltage of 14.8V at 6C (43F).
![](https://cimg6.ibsrv.net/gimg/rennlist.com-vbulletin/222x270/mid_6783f084bb2e89d13b25281eb825189301d42c03.jpg)
#380
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I changed the battery on my 2017 991.2 and this post was very helpful. A couple of notes from my install:
- Standing in the frunk was a big help.
- I used Interstate battery MTX-49 H8. This was formerly the MT5 that has now been branded an MTX.
- I plugged my battery tender into the cig lighter and it did absolutely nothing. It did not charge the car/help maintain power. I lost no settings when disconnecting the battery. The car was disconnected for roughly 15 minutes while I cleaned things up in the battery tray and surrounding area. I'm convinced you don't need to have the car connected to power when changing the battery.
- My original Porsche battery was on its last leg. I was actually losing some functions when driving the car - like the XM antenna. There was a warning on the dash that I needed to drive the car for an extended period of time to charge the battery.
#381
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I changed the battery on my 2017 991.2 and this post was very helpful. A couple of notes from my install:
- Standing in the frunk was a big help.
- I used Interstate battery MTX-49 H8. This was formerly the MT5 that has now been branded an MTX.
- I plugged my battery tender into the cig lighter and it did absolutely nothing. It did not charge the car/help maintain power. I lost no settings when disconnecting the battery. The car was disconnected for roughly 15 minutes while I cleaned things up in the battery tray and surrounding area. I'm convinced you don't need to have the car connected to power when changing the battery.
- My original Porsche battery was on its last leg. I was actually losing some functions when driving the car - like the XM antenna. There was a warning on the dash that I needed to drive the car for an extended period of time to charge the battery.
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UH2 (11-04-2021)
#386
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Nice thread! I need to replace my original Banner battery for my 2013 991.1 CS2. I'd say the stock one has been perfect for nearly 8 years! Never put a trickle charge on it. Maybe if I had I would have squeezed more time(?). (I got a CTEK now.)
I read all the options here. I was hoping to buy a stock battery (same size and part number). I can't imagine a better battery considering past performance. I called Suncoast and they do not sell batts online any more. $200 +- sounded good. Local So Cal dealer wants $469 for stock battery (without installation). I emailed my local independent shop to see what options they have.
If the only other alternative is to spend $500 or $600, I may just go with the cheaper Duracell or Interstate option. Honestly, I'm not a fan of plugging in those oversized pigs into my car. But if it saves me $300 or $400, guess I have to bend.
I don't see why someone does not offer a exact copy of the original without the "P" on it. If some knows of another resource, I'd love to know.
Take care!
I read all the options here. I was hoping to buy a stock battery (same size and part number). I can't imagine a better battery considering past performance. I called Suncoast and they do not sell batts online any more. $200 +- sounded good. Local So Cal dealer wants $469 for stock battery (without installation). I emailed my local independent shop to see what options they have.
If the only other alternative is to spend $500 or $600, I may just go with the cheaper Duracell or Interstate option. Honestly, I'm not a fan of plugging in those oversized pigs into my car. But if it saves me $300 or $400, guess I have to bend.
I don't see why someone does not offer a exact copy of the original without the "P" on it. If some knows of another resource, I'd love to know.
Take care!
#387
Racer
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I replaced my OEM a few months ago on my 12.5. Bought a Champion AGM at Pep Boys for about $180. Wasn't going to pay the P-tax for a "Porsche" battery @ 350+-. Yea, it's a bigger case but who cares?...not me.
Last edited by jimmiejam; 02-01-2021 at 02:09 PM.
#388
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Just noticed Reply #311 above (man, this is one hell of a thread). If the H6 is as at least as good as the stock maybe that will suit me. Wondering if my 999.611.070.10 is an H6.
#389
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Porsche genuine ones are about $250 discounted. Part# 992-915-105-A For this price I would prefer the factory one
https://www.sunsetporscheparts.com/o...ery-992915105a
https://www.getporscheparts.com/oem-...ery-992915105a
https://www.sunsetporscheparts.com/o...ery-992915105a
https://www.getporscheparts.com/oem-...ery-992915105a
Last edited by bb964; 02-01-2021 at 02:18 PM.
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#390
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In my case, I have an original Porsche H7 battery which is 315 mm long (12.4") x 175 mm wide (6.9") x 190 mm high (7.5"), made by BANNER Austria. 80Ah.
Pick a battery from a manufacturer, one that actually makes the battery like East Penn instead of a label from an auto parts store.
Enter your data.
Last edited by IXLR8; 02-04-2021 at 10:24 PM.
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