im want to build a discharging circuit using arduino to discharge a 300mAh 8.4v NiMh cell. been doing some research on the web for weeks now and stumbled upon a constant current sink circuit using tl431. The circuit is on page 8 of the datasheethttp://www.100y.com.tw/pdf_file/38-ON-TL431,NCV431.pdf
before building the circuit i would like to get some suggestion from fellow arduinians. Do i have to use high wattage resistor for Rs? or is there any better or easier way to discharge a battery at 100mA??