This breakout board will solve all your power-monitoring problems. Instead of struggling with two multimeters, you can just use the handy INA219B chip on this breakout to both measures both the high side voltage and DC current draw over I²C with 1% precision. Most current-measuring devices such as the current panel meter are only good for low side measuring. That means that unless you want to get a battery involved, you have to stick the measurement resistor between the target ground and true ground. This can cause problems with circuits since electronics tend to not like it when the ground references change and move with varying current draw. This chip is much smarter it can handle high side current measuring, up to +26VDC, even though it is powered with 3 or 5V. It will also report that high side voltage, which is great for tracking battery life or solar panels.