Correct testing of small batteries with a multi-meter.

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I have a LAP MAS830B multi-meter and although I am capable of testing the voltage of small batteries, AA, AAA, etc. by having the leads plugged in the sockets as shown and turning the dial anti-clockwise to 20V I have thought for some time that I wasn’t getting the full picture.
IMG_8009.JPG


A lot of batteries displayed 1.2V, 1.5V etc. and yet they were not giving the performance that they should. And so I investigated and found that the batteries should really be tested I when under load. If you jump to 1.26 on this video you will what I mean :

If you jump to 7.21 on this video there seems to be a better way of testing the batteries :

I don’t think my Lap manual is very helpful, hence the question on here if I may ? Is there any way that I can swap the leads round (as shown in the 2nd video) or if not, what and where do I buy something that resembles what is shown in the 1st video ?

Thanks in advance for any help and/or advice.
 
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Depends on what batteries you are testing ….if they are rechargeable then you may get the correct voltage but they may have no AH
Normal Standard AA batteries start at 1.5v and and drop
 
Your LAP multimeter can measure DC currents of up to 10A, as with the Fluke in the video.
Move the red test probe to the current socket on the left hand side (Remember to move it back afterwards).
And select the 10A DC current range from the dial.

IMG_8009.JPG

Be careful copying this method, this is only suitable for small capacity batteries like AA and AAA cells - the currents involved can be very close to the fuse rating of the meter.
Keep the probes connected only very briefly, or it could break your meter and kill the battery!
 
Depends on what batteries you are testing ….if they are rechargeable then you may get the correct voltage but they may have no AH
Normal Standard AA batteries start at 1.5v and and drop
Thank you. I sometimes need to test C & 9V batteries as well.
 
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Your LAP multimeter can measure DC currents of up to 10A, as with the Fluke in the video.
Move the red test probe to the current socket on the left hand side (Remember to move it back afterwards).
And select the 10A DC current range from the dial.

View attachment 368123
Be careful copying this method, this is only suitable for small capacity batteries like AA and AAA cells - the currents involved can be very close to the fuse rating of the meter.
Keep the probes connected only very briefly, or it could break your meter and kill the battery!
That was really very helpful. Thank you. I actually wondered if I could do the same with my multimeter as in the 2nd video. When I am testing the batteries like this what sort of figure am I looking for on the screen ?

I presume that I wouldn't be able to test C and 9V batteries ?
 
Thank you very much indeed for that. I knew that they existed but wasn't sure if they would do all that I want them to do. I just looked at some and this one looks pretty comprehensive. https://www.amazon.co.uk/SNUNGPHIR-...36109428&s=electronics&sr=1-5&ts_id=431409031

Would that tell me all I want to know about my batteries. I apologise for my ignorance but I am not a sparky at all.
 
Thank you for that. The problem is that I just would not know what to buy.
Like I said, get one of the battery testers I linked to.

The big concerns is that if you use your multimeter set on amps and forget to change it back fo volts before it's next use you will have a dead short through your meter. This will at minimum blow your meter to bits, and potentially blow your face to bits too if you are too close.

Thank you very much indeed for that. I knew that they existed but wasn't sure if they would do all that I want them to do. I just looked at some and this one looks pretty comprehensive. https://www.amazon.co.uk/SNUNGPHIR-...36109428&s=electronics&sr=1-5&ts_id=431409031

Would that tell me all I want to know about my batteries. I apologise for my ignorance but I am not a sparky at all.
It looks like it yes.
 
Like I said, get one of the battery testers I linked to.

The big concerns is that if you use your multimeter set on amps and forget to change it back fo volts before it's next use you will have a dead short through your meter. This will at minimum blow your meter to bits, and potentially blow your face to bits too if you are too close.


It looks like it yes.
Thank you once again for your help. It was just the sort of advice that I was looking for. I had seen that there was a danger in not reverting back to volts on the multi-meter and because of that I will buy a specific battery tester. Thank you.
 
I put a 100 ohm resistor across the terminals of a typical household battery, and measured the true voltage taking account of internal resistance
 
An AA cell covers a whole range of cells, some primary some secondary and the problem with the primary cell often very little is given about that the cell can do.

If I look at this one 1736130386062.png it says "High Capacity: 16 pack of Powerowl non-rechargeable 3000mAh 1.5V lithium AA batteries with light weight(15g/1pc)and long lifetime(10 years)." I was looking for the discharge chart, I did find a general chart
1736130725824.png
and I was considering using the lithium primary cell for my cat flap, as it holds the voltage better towards end of life, and removing an alkaline battery I find loads of energy left, and they will work my mouse on the laptop with no problem long after they have failed on the cat flap.

I find there are many items where you can't use secondary cells, as their voltage is slightly lower, it even tells you not to use them on the device instructions, but also the shelf life of a secondary cell can be short, often they will self discharge within 3 months, but not all, so it is rather hard to work out which to use.

My desk has a load of secondary AA cells on it, 700 mAh, to 2500 mAh and this causes a problem with charging, as the early chargers had timers built in, and would stop recharging before the latter cells were fully charged, as to over charging the early cells not sure what happens.

However to test a cell the easy option is use a unit designed for the job
1736131780224.png
I have used one of these for years, one gets to learn what to expect, although I have used a multi-meter when tester not to hand. With a multi-meter a primary cell is normally better than 1.5 volt when new, although you may still be able to use a battery showing 1.4 volt, I have found often they will not perform under load.

The worse item I have which needs AA batteries is my flash gun, I have bought new batteries and had them fail, or only 4 or 5 flashes from them, some flash guns if you use secondary cells it will damage the flash gun, more expensive flash guns do seem to be OK with secondary cells, and mine I found the better quality secondary cells could give me 100 flashes, so I went over to only using secondary (rechargeable) cells.

I assume it was the high current requirement of the flash gun to re-charge the capacitor that was the problem, and to cause the flash some flash guns the thyristor would short out the battery for a few milliseconds which is why with some flash guns using secondary cells would destroy the unit. Also had to be careful with voltage on the hot shoe, some used around 250 volt on the hot shoe, which could damage new DSLR cameras, mine only used extra low voltage of around 6 volts on the hot shoe, I did measure it.

The TRV heads show the voltage of the pair of AA cells, as does my wall thermostat, but I did have one wall thermostat which would not show the discharged battery icon, but would fail to work, and items designed to use secondary cells like cordless telephones, where swapping the NiCad for NiMh cells caused the newer cells not to fully charge.

Early NiCad chargers used the drop in voltage to sense when charged, at a constant current, the voltage would raise, then just before fully charge it would drop slightly, and the charger would sense this drop, and start a timer, the same does happen with NiMh but not as marked, look at Wikipedia and it shows what is inside some AA batteries
1736133655956.png
to prevent over and under charge, when you look at that, it is clear shorting out a battery to test it is rather silly, in fact with some it could be dangerous, there are loads of reports about battery fires
1736133944113.png
and although not a fire, I have had a AAA cell explode when in error recharged, the thing was it was not while being recharged it went bang, but some time latter when my mouse flew into pieces on my desk, it destroyed the mouse.

Most secondary cells at 1.3 volt, but not all, I have had some 1.5 volt secondary cells, the big problem is the writing is so small, I often have to wear two pairs of glasses to see using my mobile phone on macro setting yes can read the writing but this
1736134661032.jpeg
Is far to small to see with naked eye Warning: Insert correctly (+/-). Do not recharge. Do not throw in fire. Using 4 languages too easy to miss, and most of my rechargeable have a silver label so very easy to get mixed up. And the 1.5V is slightly larger, but still hard to see without two pairs of glasses, so to test batteries by shorting it is far too easy to do it with a secondary cell in error.

And for me my multi-meter does not have a hard wired amp range,Clamp-meter-small.jpg so could not test that way even if I wanted to. And at under £2 for correct tester 1736135305446.png why would you want to test with a multi-meter?
 

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