Hello all, I developed a voltage monitoring system using an Arduino Uno. The set up measures an incoming voltage (clicked in by a relay on the arduino relay shield). If that voltage is within a certain range (3.8V to 4.2V) an indicator LED will turn on/stay on. If the voltage ever falls out of that range, the LED will turn off and stay off. The goal is for the user to be able to connect the monitoring device to an input, leave it for awhile, and then check back later to see if the voltage stayed within the desired range for the duration of the time. The circuit also needs to draw about 1.4A in order to accurately represent the load we are checking compatibility for. We currently have the board powered by a single 9V battery. It performs well and is able to monitor the voltage properly, but we are struggling with the battery life. We have run two tests where the battery failed to last overnight. In order for this project to be implemented effectively, we need the battery to last at least overnight. Does anyone have tips for how to make the batter last longer? Omegle The ideas we've come up with are using 2 additional relays to alternate between 2 9V batteries or using the batteries to power an op amp that powers the circuit. We're not sure if either of these options will work well or if one is better than the other. Any advice is much appreciated. Thank you!