I recently had that lovely experience again...
I got the car going by putting a charger (in AGM mode) on the 12V battery. I then monitored the voltage and found it sagging to near 12V. My recollection is that a healthy AGM battery should be well above 12V, so yesterday I bought a new one. So far, so good, but not sure I'm out of the woods yet.
Have you checked the voltage on your new battery? I'm wondering about whether it might be an issue with the charging system (in both mine and yours.)
Good luck!
I got the car going by putting a charger (in AGM mode) on the 12V battery. I then monitored the voltage and found it sagging to near 12V. My recollection is that a healthy AGM battery should be well above 12V, so yesterday I bought a new one. So far, so good, but not sure I'm out of the woods yet.
Have you checked the voltage on your new battery? I'm wondering about whether it might be an issue with the charging system (in both mine and yours.)
Good luck!