Alkaline battery testing

Duracell has charts for their batteries showing voltage over time at different drain currents.

Matt Roberds

We have had interesting results testing the ESR of batteries using Bob Parker's ESR meter kit. I have a chart on:

Perhaps you can make a baseline for your batteries then you have a potentially non-destructive process to quickly evaluate batteries without loading them down. Or not.

John :-#)#

So according to the article you can just place the esr meter directly across the battery without damaging the meter? What effect will the two back to back diodes which I installed for protection have on this?? Lenny Stein.

Interesting idea, but I would think you would need to use a DC blocking cap. A large non-polar cap would work. Andy Cuffe

snipped-for-privacy@psu.edu

Ah, well, you will need to temporarily REMOVE the clipping diodes...perhaps a way to switch them in and out of circuit depending on the function you are testing (in = caps, out = batteries?).

John :-#)#

That would seem to beg the question if one were simply to replace that cap with say one with a 450V working voltage, would the diodes then be unnecessary? Lenny

At minimum, you would need to compensate for the ESR of the new 450V cap you introduced in series into the test leads in order to still get an accurate reading. The diode clamps sounds like a more effective way to protect the ESR meter to me since test voltage is kept below the bias voltage so they don't affect the calculated ESR.

Bob

I suspect one could put the blocking diodes AFTER the capacitor, thus protecting the unit from surges. If you are going to use the meter to check batteries then leave the protcetion back-to-back diodes off the input lugs, otherwise install them or be very sure the cap is discharged before attemtping to read.

Bob Parker put a lot of thought into designing this kit and I hazard to recommend any changes from that design.

Thanks Bob (as always).

John :-#)#

I would hate to have a "switched" arrangement for the diodes. I'm admittedly quite careless sometimes, and Invariably I would forget to switch them back in after using the meter to measure a battery and wind up blowing the micro on a charged 250V cap. Probe tips are cheap. Those diodes have saved the micro as well as my ass on more than one occaision. Lenny.