# Problem-Harbor Freight test meter

When I set my new Harbor Freight meter on battery test and test a AA, or AAA battery, it reads as 3.6 instead of something like 1.28 volts.

I took one back already and the two new ones I picked up all do the same thing they read 3.6 or 3.7, making three in a row, am I missing something?

Edit—-The meter is the cheap, sometimes freebie, Cent-Tech 7 function Digital Multimeter that goes for \$5 or \$7.00 dollars, or with a coupon giveaway. Item 69096

What battery?

Any battery, a Tenergy AAA, an Eneloop AA, a Rayovac AA alkaline.

The meter is the cheap, sometimes freebie, Cent-Tech 7 function Digital Multimeter that goes for \$5 or \$7.00 dollars, or with a coupon giveaway. Item 69096

Ah! I just pulled this meter out of my desk drawer at work and tried it on an old AAA and saw "3.3". I then pulled out the manual and read page 7 (see link here):

4. The battery amperage under a load of 370 mΩ will be displayed to a resolution of .1mA.
5.Normal amperage:
For a standard 9V (6LR61) battery = 25 mA
For a 1.5 V “AA” (LR6) battery = 4 mA
So it's not displaying voltage, but current in mA.
-Garry

My past versions of this meter read in volts, including one that I still have.

Also, how do I use the mA, what information does that give me? Is it better than knowing the volts?

I believe what it's doing is putting the battery under load and displaying the current the battery is capable of putting out at that load. The manual is saying that a AA battery should put out 4mA (or more) - or perhaps they mean 4mA is a typical unused battery. I think current is a better indicator of the battery's condition than just voltage as voltage without load can read "good" but then sag tremendously under a load and therefore not be good at all.

-Garry

If you use Ohm’s law, 0.0033 (3.3 mA) x 370 Ohms = 1.221 V.

No problems with 8 or so freebies I got.

Do they read mA or volts on the battery testing setting?

Volts. Here’s a 14500 at near full capacity.

What if you put the dial on the battery testing setting?

If you want volts, use the 20 DCV setting.

The battery test gives a mA reading as a reference on capacity where 4.0mA is approximately a new 1.5v primary. So your 3.6 reading would be a slightly used battery.

If you’ve got one with the super skinny leads like my son has, you’ll want to get or make some better ones.

Evidently they changed them, because they use to measure volts under a small load, not the mA.

Not understanding this stuff, I know that I keep asking for simple explanations, and sometimes seek duplicate answers, but is the mA reading more precise, or practical? Will I come to prefer it if I know what it means or get used to it?

Could it be you are testing a Li-ion?

The electronics in these cheap meters are good. If it was calibrated correctly at the factory, it should be good enough for what you do. The weak links in these are the switches, contacts and leads.

I’ve had several, back to when there was no battery test setting. Back then, the DCV setting was the only choice and it measured volts. For a good battery, volts is a good indication of charge level.

All of the ones I’ve seen with the battery test feature measure current under load as explained above. It has the current reference information right on the dial! For a bad battery, this test is better as explained above.

You can have a battery at full volts that cannot carry a load and acts like it is weak or not charged when put into a light.

Normally I use the DCV setting on good rechargeables and I use the battery test (and also DCV) for primaries.

Oh I forgot it had a battery testing setting. Mine reads 11.4 with my 14500. Doubt that means anything though. I think GottaZoom has it right. I rarely use primaries. The correct mA is on the dial for 1.5v and 9v batteries.

I am glad I found this forum topic. I also have one of these Harbor Freight multimeters. Mine is Item 98025. I found this forum by searching google for “AA battery ”4 mA” good bad” (without the opening and closing quotes).

I see Brad is asking for simplification, which I also would like. I am going to try to summarize what I have read thus far and also ask for experienced users of multimers to clarify.

So, to test AA / AAA, 9V batteries, and so on, using mine and Brad’s multimeter, there are two ways to test alkaline and rechargeable batteries.

OPTION 1:

1. Use the Battery setting on the multimeter. The results are displayed in mA.
As garrybunk pointed out in his instruction manual and in mine as well (though his #4 is my #5),

2. To convert this number to volts, as Chloe pointed out, it looks line one needs to take this number and divide by 1,000, and then multiply by 370.

What I don’t get is why this calculation:

gives 1.11 instead of 1.221 volts? Is that an error or am I missing something?

OPTION 2:

To get the results in volts directly, turn the dial to 20 on the DCV area. 200 will also work, but it’s best to use a number as close as to what you are measuring the voltage of and with the number chosen on the meter to be exact or slightly higher than the rated voltage of the device one is measuring. Too low and too high will not give accurate results.

Which is more accurate or better? mA / mA and then converting to volts or getting the volts directly? I have no idea.

Measuring a brand new AAA alkaline, I get 4.4 mA
If it is correct to divide that number by 1,000 and then multiply by 370, I get 1.628 V
If I measure the same battery at 20 DCV, I get 1.58 V

So, looking forward to an experienced multimeter user(s) to clarify these issue for me, Brad, and future newbies to multimeters. Thanks.

Welcome to BLF rojocru. In general a battery’s open voltage is different than when under load. The load setting is more useful to see how it will actually work in use. For example, I have some old high impedance NIMH cells that throw 1.2 volts open but under any load quickly drop to essentially nothing.