As the car battery approaches it's end of the warranty period, doesn't the alternator have to work harder to keep the battery charged? At one time I had a battery for over eight years with no problem. Then I noticed that my add-on voltmeter showed a constant 13-14 volts and about 11 open circuit. Previously my voltmeter would show around 12 volts after few minutes of driving. Then one day my car wouldn't start. After I jumped the battery the car started but my voltmeter did not indicate over 11V. So I had to get a new battery and a new alternator. Did my alternator fail because of overload due to a failing battery?
Battery Warranty Period
- Thread starter DonSoriano
- Start date
- Status
The alternator doesn't know when the warranty ends. It just does what it has to do...
What was wrong with the alternator? Did the shop owner have a boat
payment due? Alternators don't just quit, they fail in an identifiable way. If the shop can't tell you why they replaced it I'd find another shop. A set of new brushes for an alternator might cost 15 bucks.
payment due? Alternators don't just quit, they fail in an identifiable way. If the shop can't tell you why they replaced it I'd find another shop. A set of new brushes for an alternator might cost 15 bucks.
Last edited:
Sounds like the battery shorted a cell.
Since each cell likes to ride at two-and-a-few-tenths volts, the electrically missing, shorted one meant the others got nearly-three-volts to charge with. This boiled them dry and put an unusual load on the alternator.
I had a car that did this and it was normal-ish while driving but at idle with the headlights and blower motor on everything slowed waaaaay down.
Since each cell likes to ride at two-and-a-few-tenths volts, the electrically missing, shorted one meant the others got nearly-three-volts to charge with. This boiled them dry and put an unusual load on the alternator.
I had a car that did this and it was normal-ish while driving but at idle with the headlights and blower motor on everything slowed waaaaay down.
Anything under 12v open circuit on a car that will start itself is probably a shorted cell. You should be above 12.40+ volts after sitting with no load for 6 hours. Ideally you want to see 12.60+ here but alternators tend to keep batteries at 80% state of charge rather than higher. I periodically pull my battery and charge it with my 10A variable rate automatic chargers inside.
As far as charging voltage that varies by ambient temperatures, state of charge and vehicle model. My alternator will start out at 15.0 volts when it's negative temperatures outside at 80% state of charge and by the time everything is good and hot it's usually down to 13.6-14v. The resting voltage is far more useful than charging voltage for gauging battery health.
As far as charging voltage that varies by ambient temperatures, state of charge and vehicle model. My alternator will start out at 15.0 volts when it's negative temperatures outside at 80% state of charge and by the time everything is good and hot it's usually down to 13.6-14v. The resting voltage is far more useful than charging voltage for gauging battery health.
What was wrong with the alternator? Well, it was not charging the battery so I am assuming something was wrong. I did some basic electrical test such as measuring the output which came out 0V. Plus I had an auto shop tested it and they determined it was caput. All I want to find out in my question is is it OK to continue using the battery which was way past the warranty period although it still starts and car without harming the charging system.
Yes it's okay to use a battery as long as it works. Usually you know that the battery is going South when it needs jump started but not always.
Best bet is to carry a set of jumper cables or jump pack and worry about it when it's a certain age maybe 7 years.
I carry a Noco Genius boost so I can jump myself if need be.
Best bet is to carry a set of jumper cables or jump pack and worry about it when it's a certain age maybe 7 years.
I carry a Noco Genius boost so I can jump myself if need be.
- Status
