Go Back   Steve's Digicams Forums > Digicam Help > Batteries or Power Packs

Reply
 
Thread Tools Search this Thread
Old Dec 31, 2002, 1:05 PM   #1
Member
 
Join Date: Aug 2002
Posts: 31
Default can I use Multi-tester to measure mAh???

I am wondering if I can use my multi-tester to measure the mAh rating of some AA NiMh batteries I bought. I own some 1600 mAh NiMh ones and I just bought some 1900 mAh ones which I want to compare..

Short of charging both fully and seeing how many pics I can get out of my camera, is there another way to see if the 1900's actually hold more juice??
Thanks,
MG
mgazer is offline   Reply With Quote
Sponsored Links
Old Dec 31, 2002, 2:16 PM   #2
Senior Member
 
KCan's Avatar
 
Join Date: Jul 2002
Posts: 1,625
Default

Quote:
Originally Posted by mgazer
I am wondering if I can use my multi-tester to measure the mAh rating of some AA NiMh batteries I bought. I own some 1600 mAh NiMh ones and I just bought some 1900 mAh ones which I want to compare..
MG,
Not really … , well not directly :
mAh express the current that the source ( the battery) is able to maintain during a certain lap of time (under the reserve of the maximum absolute current value) .

For instance, a 1600 mAh battery set should be able to maintain a current of 160 mA during 10 hours , or 1600 mA during 1 hour, but certainly not 16A for 0.1 hour ( max current , check the specs)

A multi-tester usually have no other functions than measuring actual values (not “capacity”).

To be pure academic illustration, a test could be like this:

- consider 4 NiMH cells fully charged

- Use an appropriate resistor to be able to “consume” the power generated at a typical out put current , let say 500 mA (0.5 A) , a ~8 Ohms could be a choice ( it can drain .5 A with 4 Volts at it’s terminals ) .

- Connect the resistor in series with a current regulator ( set at .5 A) , and your tester as Amp-meter , and hook the whole to the battery set.
The regulator will consume the power generated by the remaining of voltage ( ~~ 6 V – 4 V ), it will get hot also …

- Chrono to see if the specs are matched
( ie : a 1600 mAh battery set should last 1600 / 500 = 3.2 hours )
KCan is offline   Reply With Quote
Old Dec 31, 2002, 5:28 PM   #3
Member
 
Join Date: Aug 2002
Posts: 31
Default thanks for the help!!!

appreciate it!
mgazer is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 3:57 PM.