I have constructed a circuit that has an Arduino Pro Mini (3.3v) along with an LCD screen (3v) that is being powered off of a single 18650 battery ( 4.2v – 3.6v). The purpose of the Arduino is to take a analog reading of the voltage of the battery while the 18650 is also powering a higher ampere secondary circuit. The problem I’m running into is when I’m running the secondary circuit, the backlight and the contrast in dimming on the LCD readout due to a drop of voltage (brings it to 2.5v) along with effecting the Arduino as well seeing that I’m running the 18650 to RAW and the VCC is out to the LCD.
Now, is there anything I can use to eliminate that voltage drop while the secondary circuit is in use? I'm not able to use a voltage regulator due to the minimal amount of provided voltage so a LM317 is out of the question... If you have any ideas, I would love to hear what you have to offer. Thank you in advanced for your help!