AA Battery capacity tester- resistor & clock

--
You did nothing wrong but believe that whoever wrote that post knew
what they were talking about.  They did not.

Hmm..... I think this is where things actually went wrong. This will never work.

What you really need to do is to connect the 1R resistor in "parallel" with the battery, not in series. This will put a hefty load on the battery (about 1.2A when it is full). The resistor (you said 10W) will still get warm, so be careful. The problem with discharging like this is that the load decreases as the battery voltage falls. This makes it a calculus problem to determine the charge that was in the battery. If you used a "constant current" load, calculating battery capacity would be as simple as timing how long it takes.

With that out of the way, I suspect that you can get an approximate capacity by using the clock as described. Assuming that it stops when the battery voltage drops to about .8V AND pretending that the voltage curve is linear. You are averaging a 1A load over time, so if the clock stops at 1:30, you could sorta say that the battery had 1500mAh charge.....sorta. ;-)

"Jim Elbrecht"

** Not wired in "series" in PARALLEL !! ** Neat idea.

** So four separate clocks ?

However, for testing non rechargeable cells like AA alkalines - use a 10 to 15 ohm resistor.

Shame they will be buggered at the end of the test !

...... Phil

Thanks to all- I might set up an excel sheet to plot curves and do it the way John suggests just for curiosity's sake.

And yes to Phil- 4 clocks- mounted -snip-

Aha! I can't find the post now to see if I misread- or he mis-wrote. At any rate- that's the ticket.

-snip-

For my purposes this will work fine. I've found that usually when a 'set' of batteries goes bad, it really means *one* has bit the dust. This will locate that one with a minimum of fuss.

Thanks again- Jim

On Sat, 28 Jul 2007 13:40:08 +1000, in message , "Phil Allison" scribed:

Maybe not completely buggered, but indeed, each time a DC load test is performed on a battery, the lives of the cells are shortened.

OP might want to invest in a pulse tester, which may be less stressful on the cells. I don't have any experience with these, so perhaps someone might care to weigh in on the subject? I did find this:

"Charlie Shitegrist" "Phil Allison"

** They are 100% dead at the end of the test

- you FUCKING IDIOT ! !

** No - YOU need to invest in one of those ....

Just to see if you are DEAD or not.

IMBECILE !!

........ Phil

--
AA alkalines are _primary_ cells and can\'t be recharged like
secondary cells can so, LOL, at the end of the life test the
alkaline cell will be dead!  Looks like Phil gotcha... ;)

On Sun, 29 Jul 2007 03:09:58 +1000, in message , "Phil Allison" scribed:

Well, I'm not the idiot who posted a recommendation to do a load test on non-rechargeable batteries, that would have been, ah, you. I'm only the idiot who overlooked the fact that some imbecile, in reference to a question about load-testing NiMH batteries, posted a recommendation on how to load-test alkaline batteries. In an objective idiot comparison, I think you'd win.

So, there's your cue. You set a trap in the hopes that you would be given the chance to spew some puerile venom. Good work! However, in doing so, you've only shown yourself to be the imbecile. Now, start a thread entitled "Charlie Siegrist = PANKING MORON" or some such other puerile nonsense, and thus try to shield yourself from the fact that you've once again pathetically out-idioted yourself.

"Charlie Shitegrist"

= FUCKING IDIOT ! !

** No - YOU need to invest in one of those ....

Just to see if you are DEAD or not.

IMBECILE !!

Why are you bringing this up? The thread is about rechargeable batteries.

Did you figure that out only after trying it yourself?

"Anthony FUCKHEAD CUNT Fremont"

** Cos 1 ohm load is not suitable for testing all kinds of AA cells - alkalines for example. ** The thread is about a neat technique for testing cell capacity with a clock.

See the bloody heading ??

Try f****ng reading it - you autism f***ed pile of

STEAMING DOG SHIT !!!!!!!!

...... Phil

Again, you have completely missed the point of my question. sigh.....

But I'll go ahead and bite anyway. How can you make that assumption? Perhaps someone wanted to test some non-rechargeable alkalines and they were destined for a high current application (like say powering a video transmitter on a model rocket/plane). IOW, why do you assume a ~20 hour discharge as the only viable test?

s/a neat/debugging an obvious/ s/cell/rechargeable cell/

NiCd chargers have been doing basically the same thing for DECADES.

Yes I do, it looks arguably like you are threatening my life. At any rate, had you been able to grasp the context of the thread, you would have noticed that the OP was only testing rechargeables. I think you purposely threw in that tripe about alkalines to bait Charlie.

BTW there are rechargeable alkalines, so technically you weren't even completely correct with your blanket statement about them necessarily being "buggered".

This is SEB Phil, why can't you at least try to restrain yourself here. You get to act an ass in plenty of other newsgroups, why can't you treat this on like it's holy ground or something?

HAND :-)

"Anthony FUCKHEAD CUNT Fremont"

** Cos 1 ohm load is not suitable for testing all kinds of AA cells - alkalines for example. ** The thread is about a neat technique for testing cell capacity with a clock.

See the OP's bloody heading ??

Try f****ng reading it - you autism f***ed pile of

STEAMING DOG SHIT !!!!!!!!

...... Phil

"Anthony FUCKHEAD CUNT Fremont"

** Why doesn't someone kill this vile public menace & autistic mental retard ???

Then ask for a medal.

...... Phil