Using meter to test a 1.5v DC battery

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Old 05-19-15, 07:34 PM
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Using meter to test a 1.5v DC battery

When I set my battery tester to 1.5 volts with the leads in their proper places and test a low battery it reads around 3.7. So I assume that means ohms. A fresh battery tests around 4.3. So my first question is why doesn't the tester just give a voltage readout. So 3.7 ohms signifies a low battery then. Why do they make something simple difficult and just give me the voltage.
 
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Old 05-19-15, 07:50 PM
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Is this an analog or digital meter ?

It sounds like an analog meter and maybe you're reading the wrong scale. If you can post the make and model of the meter we can help you further.
 
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Old 05-20-15, 06:00 AM
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I wonder if you are testing a 1.5 volt battery. 3.7 volts is appropriate for a lithium battery.
 
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Old 05-20-15, 06:06 AM
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You should not set a meter to 1.5 or 2 volts when testing a battery that should deliver 4.3 volts (or any higher voltage than the meter setting you chose)..

Some meters will still give a correct reading. Some meters will give a "out of range" report. if the actual voltage you are trying to measure is much higher than the meter setting you could burn out the meter.

Measuring the voltage of a battery standing alone usually does not give a good indication of how strong or weak the battery is. Meaningful testing of a battery requires putting a load on the battery and therefore the act of testing including using those mini-testers that came attached to the side of some batteries, consumes some of the battery's power.

One good way to test the battery is to measure the voltage while the battery is in the radio or smoke detector or other device that is switched on. This is usually not easy since the battery might be completely enclosed and not accessible such as in a tubular shaped flashlight.
 
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Old 05-20-15, 06:40 AM
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And you're confusing ohms with volts, two different animals.
 
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Old 05-20-15, 04:11 PM
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Do not use the ohms function on an energized circuit. There is a very good chance of burning out the meter.
 
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Old 05-20-15, 06:23 PM
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The meter is a 'Cen-Tech' digital multilmeter. So I set it up as it says in the instructions and at the bottom of the instruction sheet it states that for a 1.5volt battery it is normal to be 4mA. Whatever that means. Again, why don't they make it simple and just give a voltage readout. I am thinking that maybe on another setting of the Range Selector they might give a voltage readout but I don't know which one.
 
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Old 05-20-15, 06:31 PM
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You didn't leave an actual model number so I'll give generic info. There appears to be two models sold at Harbor Freight. They both have similar scales.

You will want to set the meter to the 20VDC scale. You will be able to read the battery voltage directly on the LCD screen.

Now... this will be an actual voltage reading which means a 1.5v battery, like an AA or AAA or C or D battery should show over 1.5vdc for it to be good. This is called a surface charge measurement..... the battery is not under load. If the battery reads under 1.5v then it's probably not good for most applications.
 
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Old 05-21-15, 05:20 AM
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Oh, by the way, do not confuse AC volts (or VAC) with DC volts (VDC) when using your meter. Batteries must be tested using the VDC scale. House current must be tested using VAC.
 
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