Author Topic: Alkaline battery tester  (Read 5227 times)

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Offline wolf9545Topic starter

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Alkaline battery tester
« on: August 06, 2017, 07:35:37 pm »
I have been building electronic projects for a while but have never really designed anything so please bare with me.

I want to make something like this: 
https://www.amazon.com/ANSMANN-ENERGY-BATTERY-TESTER-ALKALINE/dp/B000KHVKV6 but I don't want to spend the almost $100 just to test some batteries.  I would like to be able to test AA, AAA, C, D, coin cell and 9V batteries.  I wanted to test the battery under a load because I know you will get a better idea of the current capacity. 

I figured I would make something like the harbor freight multi-meters that have a battery tester function.  They just pass the battery through a 360ohm resistor and display the mA on the meter.  More info for anyone that doesn't know: http://www.instructables.com/id/Add-Battery-Test-to-a-Multimeter/

I ended up buying this meter:  https://www.amazon.com/gp/product/B00D2M623C/ref=oh_aui_detailpage_o04_s01?ie=UTF8&psc=1 and I put a 360ohm resistor inline with the tester side.  That way I can get a reading of 25mA for a 9V, 4mA for a 1.5. 

What I am wondering is if there is a better way to check the batteries?  I found this circuit: https://www.eeweb.com/blog/extreme_circuits/battery-tester-circuit-schematic.  Would I get a better idea if a battery is good or not?  If I read the article and schematic right I would connect a volt meter to the circuit and watch the numbers.  If I am testing a 1.5V battery I would see if 1.5 stays steady on the meter or drops.

Sorry about the massive amount of links.
 

Offline rdl

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Re: Alkaline battery tester
« Reply #1 on: August 07, 2017, 01:38:45 pm »
Checking a battery under load is probably the best way, but it seems like the load should be scaled to fit the capacity of the battery.
 

Offline sasa

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Re: Alkaline battery tester
« Reply #2 on: August 07, 2017, 03:02:38 pm »
Calculating  internal battery resistance will give a bit more reliable info of the status and future life of the battery.

For a bit more concrete info:
https://learn.sparkfun.com/tutorials/measuring-internal-resistance-of-batteries
The 30+ years professional desktop software designer and software engineer
 

Offline Kleinstein

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Re: Alkaline battery tester
« Reply #3 on: August 07, 2017, 05:42:02 pm »
With alkaline cells just measuring the voltage is usually good enough. However this does not work with the old style dry cells: they show some 1.52 V all the way till the end. So to test the dry cells one would need a load.

An alkaline cell starts at some 1.6 V  with a low internal resistance (e.g. < 0.1 Ohms for AA). When about empty they have some 1-1.2 V and still a low resistance maybe in the 0.1-0.5 Ohms range. In contrast the dry cell may start at 1.53 V with a reasonably low impedance (maybe 0.5-1 Ohms) - when empty its at something like 1.5 V but the internal resistance goes really up and can reach 100 kOhm (depending on how empty). So testing would be ideally without an with a certain load (e.g. 10 mA). So one would get both the open circuit voltage and the output resistance.
 

Offline wolf9545Topic starter

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Re: Alkaline battery tester
« Reply #4 on: August 24, 2017, 09:56:51 pm »
Thank you for all your help.  Sorry I am replying so late, I never got any notification that people replied.

I did find this circuit:

https://www.eeweb.com/blog/extreme_circuits/battery-tester-circuit-schematic

and I am waiting for the components to arrive.  I like the idea of a constant current to act as a load.  Like the description says I will then look to see if the meter stays on a steady voltage for the battery or it decreases.  I wish I could use a digital volt meter so all you would have to do is read the digits.  I could not find any that worked on 1.5V. I ended up getting a analog meter that goes up to 20V.
 

Offline rdl

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Re: Alkaline battery tester
« Reply #5 on: August 26, 2017, 11:36:44 pm »
LCD panel meters can run a long time from a 9 volt battery as long as there's no backlight on all the time.
 

Offline 6PTsocket

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Re: Alkaline battery tester
« Reply #6 on: August 25, 2018, 11:01:41 pm »
The apprropriate test load really depends on the application. A battery can have high internal resustance and still run a device that draws very little current. Any tester that has load resistors estimates what they consider a typical load.

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Offline floobydust

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Re: Alkaline battery tester
« Reply #7 on: August 26, 2018, 01:07:16 am »
I use an old analog Radio Shack Micronta 22-032 battery tester. The pass/fail voltages are in this table.
It uses 10R load for 1.5V 150ma, 30R load for 1.5V 50ma.
« Last Edit: August 26, 2018, 01:08:52 am by floobydust »
 

Offline yo0

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Re: Alkaline battery tester
« Reply #8 on: February 17, 2020, 08:15:35 pm »
Calculating  internal battery resistance will give a bit more reliable info of the status and future life of the battery.

For a bit more concrete info:
https://learn.sparkfun.com/tutorials/measuring-internal-resistance-of-batteries

you can test batteries with a esr meter, "blue esr meter" is a good one for that.


Quote
Do you know that those bad batteries were measured good using the analog or even with a digital multimeter? The battery voltage drop the moment you connect it with a load. With the ESR meter, you don’t need to connect the battery to a load and you will know how good is the battery by just observing the ESR ohm test result. If you are not sure of the good ESR ohm value for a particular battery, you can always compare it with a good one or you can even draw up your own ESR meter chart for battery if you have the time.

best regards

Pio
 

Offline OldEE

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Re: Alkaline battery tester
« Reply #9 on: February 18, 2020, 12:49:50 am »
The best battery tester I've found is from ZTS and uses a pulse load.  The mini version that I have is $45 and it also does NiMh and lithium.

Check out the patent for more information.  https://patents.google.com/patent/US6823274B2/en

Larry
 
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