With accumulation of AA rechargable cells I've bought over
the years. Would be nice to make some kind of life tester.

I have been toying with the idea of some kind of resistor,
for load. Also run a small clock on the cell. Start the
clock at 12:00 and leave it to the next day. When the clock
stops, that tells me for how many hours the battery was
delivering power. 5:00 on the clock means 5 hours of power
delivery.

The reason being so I could tell which batteries to trash,
and which ones are still useful. Is any such device already
made?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..

Stormin Mormon wrote:
With accumulation of AA rechargable cells I've bought over
the years. Would be nice to make some kind of life tester.

I have been toying with the idea of some kind of resistor,
for load. Also run a small clock on the cell. Start the
clock at 12:00 and leave it to the next day. When the clock
stops, that tells me for how many hours the battery was
delivering power. 5:00 on the clock means 5 hours of power
delivery.

The reason being so I could tell which batteries to trash,
and which ones are still useful. Is any such device already
made?

how about a flashlight?

On Dec 7, 10:14*am, "Stormin Mormon"
wrote:
... Is any such device already
made?

--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.

This smart battery charger made by PowerEx (Maha) measures capacity
and is available through Amazon for about $55:
http://www.mahaenergy.com/store/view...?idproduct=423 Battery
capacity measurements can vary quite a bit depending upon the
discharge rate (profile), but PowerEx has a good reputation for their
products.
Here’s a PC-based system if you want to spend $800:
http://www.all-battery.com/uba5multi...danalyzer.aspx
There are much more expensive battery tester/analyzers made for labs
(science/industry)
Here’s a decent article on rechargeable batteries:
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

On Dec 7, 11:14*am, "Stormin Mormon"
wrote:
...
The reason being so I could tell which batteries to trash,
and which ones are still useful. Is any such device already
made?
Christopher A. Young

The battery test function on this Harbor Freight multimeter:
http://www.harborfreight.com/cpi/cta...emnumber=90899
displays the current the battery can push through a 370 Ohm resistor.
They suggest a good 9V battery can do 25mA and 4mA for a 1.5V cell.

I've noticed some old cells that show the right voltage open circuit
but show up as high resistance on this test.

This serial port datalogger can record the voltage as a battery
discharges through a resistor.
http://www.dataq.com/products/startkit/di194rs.htm
The free included software doesn't let you shut off the load at an
endpoint voltage, so it's not good for rechargeable Lithiums. AFAIK
individual NiCads don't mind discharging to zero. When multiple cells
are in series the first one down will be charged backwards by the
others, which is damaging

When I get to that project I'll use an old laptop running QBasic under
DOS and control the load with a printer port bit. They have USB
versions but I can't program them directly.

Another possibility:
http://www.zeitnitz.de/Christian/scope_en
DC coupling the input is possible but risky.

Dec 7 note:
NH just named a new bridge for Pearl Harbor.

jsw

Seriously good information. Thanks. I might buy myself one
for Christmas.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Denis G." wrote in message
...
On Dec 7, 10:14 am, "Stormin Mormon"
wrote:
... Is any such device already
made?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
.

This smart battery charger made by PowerEx (Maha) measures
capacity
and is available through Amazon for about $55:
http://www.mahaenergy.com/store/view...?idproduct=423
Battery
capacity measurements can vary quite a bit depending upon
the
discharge rate (profile), but PowerEx has a good reputation
for their
products.
Here's a PC-based system if you want to spend $800:
http://www.all-battery.com/uba5multi...danalyzer.aspx
There are much more expensive battery tester/analyzers made
for labs
(science/industry)
Here's a decent article on rechargeable batteries:
http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

I remember the original carbon zinc cells, would read fine
with VOM, but could be dead to any load. I made a load
tester with a PR-2 bulb, and a piece of 10 gage wire. Make a
loop around the bulb, cnd then curl the wire in to a C
shape. Lead tip of the bulb on the battery, and end of the
wire on the other end of the battery. I can do a quick,
practical test of AAA through D cells.

By the brightness of the bulb (or light at all) I can
quickly tell if a battery is new, used, or useless.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Jim Wilkins" wrote in message
...

The battery test function on this Harbor Freight multimeter:
http://www.harborfreight.com/cpi/cta...emnumber=90899
displays the current the battery can push through a 370 Ohm
resistor.
They suggest a good 9V battery can do 25mA and 4mA for a
1.5V cell.

I've noticed some old cells that show the right voltage open
circuit
but show up as high resistance on this test.

I have one of these

http://www.hobbypartz.com/thac6smbachw.html

similar to

http://www.hobbypartz.com/skychb6chdup.html

You can set them to discharge and charge a battery multiple times and they
will tell you the capacity in milliamp hours. They work on NiCd, NimH,
Lithium ion, Lithium Polymer, lead acid, charge from 0.1 to 5A... just check
the specs. Connect to PC, cable and software included.

In my opinion they are a great charger for the money.

RogerN


"Stormin Mormon" wrote in message
...
With accumulation of AA rechargable cells I've bought over
the years. Would be nice to make some kind of life tester.

I have been toying with the idea of some kind of resistor,
for load. Also run a small clock on the cell. Start the
clock at 12:00 and leave it to the next day. When the clock
stops, that tells me for how many hours the battery was
delivering power. 5:00 on the clock means 5 hours of power
delivery.

The reason being so I could tell which batteries to trash,
and which ones are still useful. Is any such device already
made?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
.

On Mon, 7 Dec 2009 11:14:03 -0500, "Stormin Mormon"
wrote:

With accumulation of AA rechargable cells I've bought over
the years. Would be nice to make some kind of life tester.

I have been toying with the idea of some kind of resistor,
for load. Also run a small clock on the cell. Start the
clock at 12:00 and leave it to the next day. When the clock
stops, that tells me for how many hours the battery was
delivering power. 5:00 on the clock means 5 hours of power
delivery.

The reason being so I could tell which batteries to trash,
and which ones are still useful. Is any such device already
made?
I made something like this with a relay, wired to self latch, a Hobbs
hour meter and an assortment of light bulbs for loads. I used NO and
NC push button switches for start and stop. I use it to test the
capacity of 12 V. gel cell batteries. when the output voltage drops
below about 8 V. the relay drops out and, of course the meter stops.
First time SWMBO went past the shop and saw the red pilot light and
heard the meter ticking over, she accused me of building a time bomb!
You would need to find a relay and clock that would run on 1.2 V.
Gerry :-)}
London, Canada

Gerald Miller writes:

I made something like this with a relay, wired to self latch, a Hobbs
hour meter and an assortment of light bulbs for loads. I used NO and
NC push button switches for start and stop. I use it to test the
capacity of 12 V. gel cell batteries. when the output voltage drops
below about 8 V. the relay drops out and, of course the meter stops.
First time SWMBO went past the shop and saw the red pilot light and
heard the meter ticking over, she accused me of building a time bomb!

You would need to find a relay and clock that would run on 1.2 V.

Relay yes, but the clock/timer could & should run on external voltage, so it can
be any voltage.
..
But... don't try a digital alarm clock...

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On Dec 7, 6:40*pm, "RogerN" wrote:
I have one of these

http://www.hobbypartz.com/thac6smbachw.html

similar to

http://www.hobbypartz.com/skychb6chdup.html

You can set them to discharge and charge a battery multiple times and they
will tell you the capacity in milliamp hours. *They work on NiCd, NimH,
Lithium ion, Lithium Polymer, lead acid, charge from 0.1 to 5A... just check
the specs. *Connect to PC, cable and software included.

In my opinion they are a great charger for the money.

RogerN

Very interesting. I think I know what's inside but I couldn't build
one for twice that price. Can you use it as a general purpose data
logger?

jsw

Jim Wilkins wrote:

This serial port datalogger can record the voltage as a battery
discharges through a resistor.
http://www.dataq.com/products/startkit/di194rs.htm
The free included software doesn't let you shut off the load at an
endpoint voltage, so it's not good for rechargeable Lithiums.

Feed the base of a simple transistor through a bias resistor with the
battery voltage such that it turns the transistor off when you reach your
desired voltage. Run whatever part of the circuit through the
emmitor/collector of said transistor, and you have what you are looking for
at a buck or two max.

Jon

On Dec 8, 3:17*pm, "Jon Danniken"
wrote:
Jim Wilkins wrote:

This serial port datalogger can record the voltage as a battery
discharges through a resistor.
http://www.dataq.com/products/startkit/di194rs.htm
The free included software doesn't let you shut off the load at an
endpoint voltage, so it's not good for rechargeable Lithiums.

Feed the base of a simple transistor through a bias resistor with the
battery voltage such that it turns the transistor off when you reach your
desired voltage. Run whatever part of the circuit through the
emmitor/collector of said transistor, and you have what you are looking for
at a buck or two max.

Jon

When I discuss electronics in this machining forum I assume the
audience consists of those who understand it and don't need my simple
advice, and those who don't and won't build the circuit anyway. I
can't teach circuit design and soldering by correspondence. It's the
same with chemistry.

You have the right general idea but need a circuit that shuts the load
control off abruptly, such as a comparator with hysteresis. Remember
that the battery voltage will rise when the load is removed.

jsw

"Jim Wilkins" wrote in message
...
On Dec 7, 6:40 pm, "RogerN" wrote:
I have one of these

http://www.hobbypartz.com/thac6smbachw.html

similar to

http://www.hobbypartz.com/skychb6chdup.html

You can set them to discharge and charge a battery multiple times and they
will tell you the capacity in milliamp hours. They work on NiCd, NimH,
Lithium ion, Lithium Polymer, lead acid, charge from 0.1 to 5A... just
check
the specs. Connect to PC, cable and software included.

In my opinion they are a great charger for the money.

RogerN
/
/Very interesting. I think I know what's inside but I couldn't build
/one for twice that price. Can you use it as a general purpose data
/logger?
/
/jsw

I just tried right now, the data doesn't start logging until a charge or
discharge has began. I have the Thunder AC 6 and downloaded the software
for the skycharger, works fine. I'm not sure if the charger doesn't send
data until it's started or if the software just doesn't start recording.

This place has a lot more chargers along with reviews

http://www.hobbycity.com

I found info on one of their reviews on how to calibrate the voltage
readings on my charger.

RogerN