2008 Ford Taurus - Battery drain where to start?

New battery…car not driven much…once a week short distance…something is draining battery.

The first step is to measure the battery current with everything turned off. It should measure less than 50 mA. It can take 20 minutes or longer after the car is turned off and the doors are locked to get everything, all the computers etc, turned off.

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The computers in the vehicle are draining the battery, try recharging the battery once a month.

Once you determine if the parasitic drain is within normal limits, my suspicion is the once a week short drive is not enough to recharge the battery.


I agree with Purebred. You might need a battery tender here.

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That “short distance” drive, once per week, is not sufficient to recharge the battery after using the starter, which uses a LOT of the battery’s charge. If the OP operates the heater and headlights during those very short drives, that means the alternator has even less of a chance of recharging the battery.

Additionally, as was already stated, the car’s computers and the car’s security system are draining the battery while the car “sits” for extended periods of time.

For the sake of the car’s battery, its exhaust system, and the engine itself, the car needs to be taken out for a highway drive once each week, for at least 30 minutes.


Yes, a battery tender will help the battery, but unless the OP begins to drive the car as it was intended to be used, the engine and the exhaust system will suffer greatly.

Note to @Dannis:
In case you are not aware of it, all car manufacturers define your current usage of the car as “severe service”. That type of usage mandates that the oil be changed at least every six months in order to prevent an accumulation of damaging sludge that is deposited in the engine as a result of driving it only for short distances.

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We are in agreement

You used to mention a much higher number

What changed your mind . . . ?!

hopefully the three or four hundred times you told him otherwise?? :thinking: :thinking: :rofl: :rofl:

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I have a feeling he learned it the hard way . . .

He may have measured a 500 milliamp draw with his multimeter and decided it was okay . . . only to have have a dead battery in the morning :wink:

nothing teaches better than experience! My friend is a master plumber in Tennessee and has said this many times when he gets apprentice plumbers working with him.

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This is what Optima Battery Corporation says

" a 25-milliamp draw is normal and anything that exceeds 100-milliamps indicates an electrical issue"

If I suggested 500 ma is normal, that’s my mistake. But as much as 100 ma could be normal for newer cars according to Optima.

huh . . .

Well, I wouldn’t tell anybody 100 milliamps is acceptable

I’m sticking to 50 milliamps max