Help! Building homemade photo lithium battery tester

[[email protected]]

Hello, and Happy New Year to everybody.

My battery tester uses a (too weak) 10mA load for its 6V test.

I'm guessing that a 2CR5 Photo Lithium battery should be tested at
150mA, under load.

Any electronics geniuses out there? What type/size resistor should I
connect to the battery, while testing with my battery meter, to
simulate a Canon SLR's load, and provide me with an estimation of the
usability of my 2CR5 (and other 6V lithium) batteries?
I also have a DMM.

Thanks for all advise and tips.

 

[John Woodgate]

I read in sci.electronics.design that [email protected] wrote (in

Hello, and Happy New Year to everybody.

My battery tester uses a (too weak) 10mA load for its 6V test.

I'm guessing that a 2CR5 Photo Lithium battery should be tested at
150mA, under load.

Any electronics geniuses out there? What type/size resistor should I
connect to the battery, while testing with my battery meter, to
simulate a Canon SLR's load, and provide me with an estimation of the
usability of my 2CR5 (and other 6V lithium) batteries?
I also have a DMM.

Thanks for all advise and tips.

To get 150 mA with 6 V, you need 6 V/0.15 A = 40 ohms. Power dissipated
is 6 V x 150 mA = 0.9 W. If you are not going to keep the tester on the
battery for more than a minute or so, a 39 ohm 1 W resistor is OK. 39
ohms is a standard value; 40 ohms isn't. It will get warm, but not too
warm.

 

[Mark Jones]

I read in sci.electronics.design that [email protected] wrote (in


To get 150 mA with 6 V, you need 6 V/0.15 A = 40 ohms. Power dissipated
is 6 V x 150 mA = 0.9 W. If you are not going to keep the tester on the
battery for more than a minute or so, a 39 ohm 1 W resistor is OK. 39
ohms is a standard value; 40 ohms isn't. It will get warm, but not too
warm.

Also, depending on the battery used, I'm not sure 150mA is a good
idea. Some Li-ion batteries have a maximum steady-state current below
100mA. If this is the case, the readings will be erronious. Perhaps
this is why 10mA is used by default.