Dead battery mystery
Rennlist Member
Joined: Oct 2014
Posts: 6,193
Likes: 1,956
Batteries use chemical reactions to create current. These reactions slow down when the battery is cold. Therefore a cold battery drops a % of its cranking power. So you were already down 25% due to drainage ... Battery at 75%. Drop another 20% of that and you are at 60%. With the cold your starter motor isn't as efficient. So now maybe you are at 50%. Do you have a new alternator cable with better connections or the older cable? Maybe you are down to 40%, or even 30.
It doesn't take much to get into trouble. By four years, any battery is due to fail. The chemical reactions are one way, forming a precipitate that will not return to solution. The constant daily 1 amp hour drain destroys these batteries over time.
Technology has improved so the plates don't warp (as badly) and short, and the precipitate is less likely to contact the plates, but the chemistry remains the same!
It doesn't take much to get into trouble. By four years, any battery is due to fail. The chemical reactions are one way, forming a precipitate that will not return to solution. The constant daily 1 amp hour drain destroys these batteries over time.
Technology has improved so the plates don't warp (as badly) and short, and the precipitate is less likely to contact the plates, but the chemistry remains the same!
Instructor
Joined: Aug 2003
Posts: 133
Likes: 2
From: boston
Had a similar issue with my 08 c2
Ended up being the alternator. The PO didnt use the car much and essentially flat Spotted the alternator. It was a total intermittent problem, and replacing the cable and battery didn't correct it.
Interesting conversation on locking vs locked car storage. what I understand from talking to a few Indy wrenches is that after a few hrs, it makes no difference, ie- the car keeps several systems active for several hours when the car is unlocked , but then puts them to sleep.
Incidentally- over the past 2 weeks while we had salty roads in the northeast I didn't use my car. Today roads are dry and it started right up
Ended up being the alternator. The PO didnt use the car much and essentially flat Spotted the alternator. It was a total intermittent problem, and replacing the cable and battery didn't correct it.
Interesting conversation on locking vs locked car storage. what I understand from talking to a few Indy wrenches is that after a few hrs, it makes no difference, ie- the car keeps several systems active for several hours when the car is unlocked , but then puts them to sleep.
Incidentally- over the past 2 weeks while we had salty roads in the northeast I didn't use my car. Today roads are dry and it started right up
6th Gear
Joined: Jan 2015
Posts: 6
Likes: 0
From: Eugene, Oregon
6th Gear
Joined: Jan 2015
Posts: 6
Likes: 0
From: Eugene, Oregon
