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Hello friends. I have a base 997.2. Does anyone know what their healthy battery's voltage drops to when cranking? I'm getting some signs that a new battery is in my future...... Mine is at least 3 or 4 years old and maybe older. Perhaps nearing the end of life for a car that's driven once or twice a week. My multimeter is measuring only 11.8V before starting the car cold (after sitting overnight), and it's dropping to just under 10V while cranking. Drives and starts fine, but I was alerted when it threw some codes at me while cranking and then quickly self-cleared. Autozone tested the battery and said it's fine but undercharged. With the engine running, I am getting 14.3V so I think my alternator is fine. Thanks for any insight or any info if anyone knows the standard range of our batteries. Either way, I am planning on a new battery and a tender in the near future-- just being extra cautious since it threw codes.
Last edited by dougdtx; 03-26-2024 at 08:36 AM.
Reason: Clarity + making it shorter and to the point
There should be a date on the battery denoting date of manufacture.
Given your light usage, you may want to get a battery maintainer like a CTEK or equivalent and plug it in after driving. I usually get 6-7 years from my batteries given 10-15 K miles per year of use and plugging in the tender when expecting to not drive for just a few days. I don't at all think I need to plug it in but I am running a constant experiment to see how long my batteries will last using the CTEK. I mounted the CTEK on the door opener above, and hang the cable down making for easy hookup. My assumption... and it is an assumption... is that keeping the battery at a steady state without swings in discharge and charge (albeit small) will lengthen battery life..... maybe.
Peace
Bruce in Philly (now Atlanta)
Last edited by Bruce In Philly; 03-26-2024 at 11:52 AM.
Okay thank you all! I suspect on Saturday while cranking I probably dipped even below 8 or 9 volts and that's what triggered some codes on my car. I had not driven it in over a week nor did I have it on a charger and I have the old battery. Will get a new battery and tender and hope for the best. The codes seemed to have cleared themselves in the meantime.
Just a FYI Doug.
I have a Moll battery that is 10 years old ! Sits in garage on CTek when not driven.
Just checked it and it reads 12.4 standing and 10.3 cranking. Guess using the maintainer paid off big time !?
I wish all my batteries would last this long !
Just a FYI Doug.
I have a Moll battery that is 10 years old ! Sits in garage on CTek when not driven.
Just checked it and it reads 12.4 standing and 10.3 cranking. Guess using the maintainer paid off big time !?
I wish all my batteries would last this long !
Yep, keeping them on tenders makes them last forever. The last one in my 914 lasted 12 years. The one in one of my 928s is 9 years old. If I don't get 8 or more years out of one of my AGM batteries, I consider it a failure.
03-25-2024, 06:58 PM
Battery voltage levels on a 997.2
Mine is at least 3 or 4 years old and maybe older. Perhaps nearing the end of life for a car that's driven once or twice a week. My multimeter is measuring only 11.8V before starting the car cold (after sitting overnight), and it's dropping to just under 10V while cranking. Drives and starts fine, but I was alerted when it threw some codes at me while cranking and then quickly self-cleared. Autozone tested the battery and said it's fine but undercharged. With the engine running, I am getting 14.3V so I think my alternator is fine. Thanks for any insight or any info if anyone knows the standard range of our batteries. Either way, I am planning on a new battery and a tender in the near future-- just being extra cautious since it threw codes.
