Skip the auto shop - Our mechanics make house calls

Q: Parasitic battery drain

asked by on

While my car is off there is a drain on the battery, I measured the drain and found it averages out at about .50 amps. I'm trying to figure out if that is high, and what the normal draw on a battery is. I have replaced the battery, alternator and serpentine belt within the last three months trying to fix this with no avail. Every time I take it to a shop to have it looked into they say it's the battery even though it's brand new. Thank you for your time. -Jhad

My car has 71000 miles.
My car has an automatic transmission.

A: Hi there. The Toyota standard for battery d...

Hi there. The Toyota standard for battery draw is 50 milliamps or 0.05amps, so you definitely have a parasitic draw. Check the obvious culprits first: the glove box light, the interior lights, a smart key still in the car, a trunk light that was left on, and so on. Then, you can start removing fuses one at a time to see if the draw disappears. After you’ve found the right fuse, start unplugging components powered by that fuse until the draw goes away. Once the source of the draw is discovered, it can be repaired or replaced as needed. I strongly suggest having a qualified technician, such as one from YourMechanic, perform an inspection of your parasitic draw so you can avoid replacing unnecessary parts.

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

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Possible electrical issue - 2008 Dodge Avenger

Hello, thanks for writing in. A battery at 45% power is a bad battery. If it takes a charge and then is back to "45%" within hours, the battery is not holding a charge correctly. There is possibly a parasitic...

Q: Hesitation when accelerating

Hi There, The radiator fan may have stopped working for a couple of reasons such as a faulty fan motor or faulty fan relay. As you know, this can be dangerous to the motor as it may cause it to...

Q: Can a bad thermostat cause me to have to keep putting coolant in my car?

Hi, thanks for writing in. The thermostat in the engine cooling system is a valve that opens and closes as engine temperature fluctuates. The purpose of the valve is to keep the engine operating temperature at a relatively constant, optimal...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...