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enter image description hereMy 2008 Outback’s battery goes dead when it sits for a night or two. I’m looking for a parasitic leak. Can anyone help me interpret this meter reading? I have it in parallel between the neg battery post and the neg cable. The battery has been recharged. Everything except the hood is closed or turned off (doors, lights, etc.) as far as I can tell. I don’t know what the symbols on the meter mean. I included a photo of the meter with the leads removed so that you can see the symbols. Thanks for any helpmeter reading[![][1]]2 [meter]3

  • From what I can see the OP only has one battery so if you measure in series or parallel the out put should be the same. Agreed it's best to measure directly from the terminals to minimise voltage drop – Dan K Nov 21 at 15:30
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The test you are doing is not valid and shows you nothing really.

For a start, you have not got it wired in parallel, you have got it wired in series. You would usually wire a voltmeter in parallel to measure voltage. You are therefore measuring the battery voltage with some voltage dropped across whatever is turned on in the car at that moment. In a modern car, there will likely always be something drawing a small amount of current (e.g. alarm), so you will see a voltage reading as you are now.

To find a parasitic drain you really need to set your multimeter in current (Amps) mode with it connected in series. This will show you how much current is being drawn from the battery by the car. Several mA is fine, but near an Amp is not. Your multimeter only goes up to 150mA, so probably isn't suitable for the job, you could end up breaking it.

Once you have the multimeter set up to show current, in series with the battery, you can start disconnecting fuses until you find which circuit is drawing the largest current.

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I'm reading 11.5 volts DC on the second screen. Your black lead is plugged into the ground (DC-) and the red lead is connected to 15V+. If you were measuring AC volts, the black lead would go one spot to the left in the AC V jack.

Because it is connected to the 15V jack, you read the bottom scale from 0 to 15V, which is graduated in half-volt markings. Ten volts plus 3 half volts equals 11 and one-half. That doesn't seem all that healthy.

If you check it when the engine is running, you should see greater than 13 volts, or four graduations below 15 on the same scale.

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    Thanks fred_dot_u. The 11.5 volt reading was after the battery was on a charger for 20 hours. Maybe I have a bad battery. – user53707 Nov 19 at 5:07
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    The OP has the voltmeter wired in series (I believe), not parallel, therefore the reading is not valid. Won't be a good idea to try to start the car in this configuration. – HandyHowie Nov 19 at 8:04
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I agree it looks like around 11.5 volts, and it also looks like the meter is connected in series between the negative cable and the battery terminal, so that could be inaccurate. And you definitely don't want to start the car like this because it will probably fry your meter and melt those little cables pretty fast.

If you want to read the voltage properly, connect the battery terminals back up as normal, and then touch your red lead to the positive terminal (careful not to touch the frame or anything else with this lead) and the black lead to the negative.

More important than any of this is that you mention the battery has gone flat several times. Whether there is a parasitic leak or not is probably not the main issue right now, because the battery is probably toast at this point either way. These types of batteries are not meant to be ran flat over and over, and yours will have permanently lost ability to hold a charge for very long. (In fact it's just "surface charging" at this point, where it appears to get up to voltage when charged, but can't sustain that voltage for any length of time).

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