Skip the auto shop - Our mechanics make house calls

Q: Why does a car battery stay full and ready even when the car is not in use and the ignition switch is off?

asked by on

Already have.

My car has 93000 miles.
My car has an automatic transmission.

A: A battery uses basically lead and lead acid...

A battery uses basically lead and lead acid to cause a chemical reaction that produces the required voltage that a vehicle uses to run the vehicle electrical systems. The amount of material put into the battery when it was made will allow a vehicle battery to store and produce the required voltage needed to sustain a vehicles electrical system for about 3 to 5 years before a replacement battery is needed. Here is a very good explanation of how a battery works with a car's electrical system.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: How do I find and identify the ECM module in a 2001 Buick LeSabre?

Hello. To answer your location question, the ECM is behind the fuse and relay block of electronics under the passenger side of the dash (behind the glove box). The ECM is behind the other electronics, mounted flat against the firewall,...

Q: Car only staying started for five seconds

If the powertrain control module (PCM) does not have proper communication with the Sentry Key Remote Entry Module (SKREEM), the PCM will shut off fuel after two seconds of run time. A full key cycle down sequence must be performed...

Q: My 2009 Cadillac CTS won't start

I'm a bit concerned about your description of using a jumper wire to ground at the starter relay. Either you can make the starter motor turn from here, which you could if you jumper the correct terminals with power, or...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.