Introduction: Lithium Battery MAh Tester
Bought some expensive battery you want to test, or just have old one lying around youre interested in playing with?
its the project for you!
its the simplest tester you can make for only about $10, and for that price youll get to make astonishing graph.
[ITEM] youll need:
- Arduino (2$)
- Relay module (2$)
- RTC DS3231 (2$)
- MicroSD module +SDcard (2$)
- a hand full of wire
- 2LEDs (red and green) + 2X 1KOhm resistor
- LM317 (1$)
- 1-1.2Ohm resistor 5Watt (1$)
- auto cut-off @ 3v
- green LED when discharging/testing
- red LED when OFF
- Data Logging on microSD card
- 1.2Ah discharge with 1Ohm resistor (can be changed)
Step 1: Constant Current Regulator
you'll need a constant current load, easy enought when you have the circuit diagram!
i didnt put the capacitor on mine, it works good enought as is.
you'll obviosly need to look for the pinout.
PUT A HEATSINK ON IT!
find yourself an old pc and rip the chipset heatsink out of it. drill and tap you are good to go!
it will dissipate aprox 5W with a 1Ohm resistor at about 1.2Amp discha
Step 2: Shape the Data
your data will look like this:
use anything to shape it like this:
am using notepad++, go to macro->record->use to bottom of page
rename the .txt to .csv
you'll just need to input the .csv into a graph generator like datplot
DS3231 lib: http://www.rinkydinkelectronics.com/library.php?id=73