I have a device that is powered by a coin cell battery, but occasionally they fail and I would like to run them in debug mode to find the problem. Debug mode requires more power than the coin cell can produce. Sometime I want to flash new program code on them which also requires too much power for the coin cell to handle. My batteries are soldered on; it is inconvenient to remove the battery.
Is it safe to hook up a power supply in parallel to my coin cell? If the coin cell is at 2.9V, can the power supply be at 3.1V? What are the considerations for this configurations? Does anyone have a application note or paper that covers coin cells?
I don't want to put a diode in front of my battery because that causes a constant 0.7V drop.