battery tester -dry cells

[Lew Hartswick]

Years ago when I worked in the "trade" there was a
little black box for testing cells Carbon-Zinc
Alkaline etc. Does anyone have an idea of the load
resistors used for the various size cells?
D, C, AA, AAA. at least. With all the "stuff" that
is using such and an open ckt. test that always
reads very close to the new voltage, I want to
build a simple tester so even the wife can check
the "batteries" in the TV remote etc.
...Lew Hartswick...

 

[rickman]

On 6/4/2014 3:55 PM, Lew Hartswick wrote:

Years ago when I worked in the "trade" there was a
little black box for testing cells Carbon-Zinc
Alkaline etc. Does anyone have an idea of the load
resistors used for the various size cells?
D, C, AA, AAA. at least. With all the "stuff" that
is using such and an open ckt. test that always
reads very close to the new voltage, I want to
build a simple tester so even the wife can check
the "batteries" in the TV remote etc.
...Lew Hartswick...

I suggest that you not worry so much about the load and just let the
circuit measure the open circuit voltage. Any time I take alkaline
cells out of service I find the voltage is 1.2 or lower. A fresh cell
is always higher than 1.4 volts. My mouse eats a pair of AAAs in a
month or so and the terminal voltage is about 0.9 open circuit.

What the load test tells you is the internal resistance of a cell. That
can rise as the cell nears the end of life, but is just duplicate info
to the open circuit voltage. The internal resistance can tell you
something about rechargable cells however. They will have a very
different open circuit voltage being a bit above 1.2 for a fresh NiCad.
I think their open circuit voltage is fairly constant until nearly
depleted, but more importantly the internal resistance will rise as they
get worn and won't hold as much charge.

--

Rick

 

[Robert Baer]

rickman wrote:

On 6/4/2014 3:55 PM, Lew Hartswick wrote:
Years ago when I worked in the "trade" there was a
little black box for testing cells Carbon-Zinc
Alkaline etc. Does anyone have an idea of the load
resistors used for the various size cells?
D, C, AA, AAA. at least. With all the "stuff" that
is using such and an open ckt. test that always
reads very close to the new voltage, I want to
build a simple tester so even the wife can check
the "batteries" in the TV remote etc.
...Lew Hartswick...

I suggest that you not worry so much about the load and just let the
circuit measure the open circuit voltage. Any time I take alkaline cells
out of service I find the voltage is 1.2 or lower. A fresh cell is
always higher than 1.4 volts. My mouse eats a pair of AAAs in a month or
so and the terminal voltage is about 0.9 open circuit.

What the load test tells you is the internal resistance of a cell. That
can rise as the cell nears the end of life, but is just duplicate info
to the open circuit voltage. The internal resistance can tell you
something about rechargable cells however. They will have a very
different open circuit voltage being a bit above 1.2 for a fresh NiCad.
I think their open circuit voltage is fairly constant until nearly
depleted, but more importantly the internal resistance will rise as they
get worn and won't hold as much charge.

Err...Alkaline cells nominally read 1.65 brand new to as bad as 1.55V
"fresh" but sitting around for a while.
The Radio Shack tester 22-090 uses 1mA load for 1.5V button cells and
3V lithium cells; 50mA for AAA and N, and 150mA for AA, C, and D.
The meter does not specify the loading for 6V photo, 9V, 12V, 15V or
22.5V batteries.

And it is rather useful to test under load; a weak battery may
initially indicate near full voltage, but will show a sagging reading as
the meter is left connected to it (2-15 seconds).
Note a no-load test will not show a weak battery.

 

[Charlie+]

On Wed, 04 Jun 2014 13:55:27 -0600, Lew Hartswick
<LHartswick@earthlink.net> wrote as underneath :

Years ago when I worked in the "trade" there was a
little black box for testing cells Carbon-Zinc
Alkaline etc. Does anyone have an idea of the load
resistors used for the various size cells?
D, C, AA, AAA. at least. With all the "stuff" that
is using such and an open ckt. test that always
reads very close to the new voltage, I want to
build a simple tester so even the wife can check
the "batteries" in the TV remote etc.
...Lew Hartswick...

These type testers are so cheap (even cheaper from China!) its not
really worth messing around with...
I dont use for more than a second if testing on button cells! The load
resistor is the same for all ~1.5v types, higher for PP3.
eBay item number:
181298349549

 

[Lew Hartswick]

Robert Baer wrote:

Err...Alkaline cells nominally read 1.65 brand new to as bad as 1.55V
"fresh" but sitting around for a while.
The Radio Shack tester 22-090 uses 1mA load for 1.5V button cells and
3V lithium cells; 50mA for AAA and N, and 150mA for AA, C, and D.
The meter does not specify the loading for 6V photo, 9V, 12V, 15V or
22.5V batteries.

And it is rather useful to test under load; a weak battery may
initially indicate near full voltage, but will show a sagging reading as
the meter is left connected to it (2-15 seconds).
Note a no-load test will not show a weak battery.

Thanks. That is what I was looking for. somewhere around 30 and 10 ohms.
...lew...

 

[Michael A. Terrell]

Robert Baer wrote:

Err...Alkaline cells nominally read 1.65 brand new to as bad as 1.55V
"fresh" but sitting around for a while.
The Radio Shack tester 22-090 uses 1mA load for 1.5V button cells and
3V lithium cells; 50mA for AAA and N, and 150mA for AA, C, and D.
The meter does not specify the loading for 6V photo, 9V, 12V, 15V or
22.5V batteries.

And it is rather useful to test under load; a weak battery may
initially indicate near full voltage, but will show a sagging reading as
the meter is left connected to it (2-15 seconds).
Note a no-load test will not show a weak battery.

Copied from their website:

Battery Tester
(220-0090) Specifications Faxback Doc. #
37400

Current Drain During Test for each type of battery is as follows:

Battery Size Current

1.5V (AA, C, D) 150mA
AAA and N 50mA
Lithium 3V 1mA
Button Cell 1.5V 1mA
6V Photo 10mA
9V 10mA
12V 10mA
15V 10mA
22.5V 10mA


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

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