When working on battery-dependent projects you want accurate performance information where a datasheet may not be available. [E. Lelic] set out to build a device that would meter internal battery resistance but ended up with a bench tool that can do much more than that.
A PIC 16F88 microcontroller takes center stage on the meter, taking voltage level readings, monitoring a DS1820 temperature sensor, and controlling an LM2575 step-down regulator. The components provide functionality for measuring Lithium Ion, Lithium Polymer, Nickel Cadmium, Nickel Metal Hydride, and Alkaline batteries. It is capable of fully discharging and fully charging the batteries, measuring time and power consumption during this cycle, and monitoring temperature changes for the NiMH and NiCad versions.
Look for the little red ‘Download’ icon at the bottom of the post linked above. That archive includes a schematic (which we’ve also embedded after the break), board layout in .LAY format, and a HEX firmware file.
If you enjoyed this build you might want to look at this other battery capacity tester.
Also check out:
http://www.stefanv.com/electronics/battman2.html
I can’t get he source .rar file to download. Also, if there’s only a .hex file – then there’s no source – right HaD????
@Drone, you can’t read assembly?
Finally something useful and well made
i contacted the author and he tested some unknown Chinese 900mAh Alkaline batteries. they had only 470mAh capacity :) Nokia’s rechargeable original batteries actually had more capacity then they read on the package! cool
I like the design for what it does. I would make some changes: take a pwm output and filter it to a dc voltage. Use this voltage and a comparator to make a controllable discharge current that you can set in a lot of steps.
Also, the 10 ohm resistor at the output of the charger kind of limits the current, doesn’t it?
THIS! I NEED! i have 100+ 16850s of unknown condition. weekend project? i think so!
Can you please put the download again for this project (schematic, board layout and a HEX firmware file)? Thank you
Somebody? Anybody? No one?
I build this project but not working good discharge is ok but chrging not work and allways restart the tester