Figure 7.

Data logger battery discharge curves for units with similar hardware powered by 3 × 1.5 V alkaline batteries in series. The 0.33 mA data logger built in early 2014 slept between readings but had no other power management. The 0.25 mA data logger used the described code-side techniques but had no hardware power optimization. The 0.1 mA data logger had software and hardware power optimizations, including an MCP1700 regulator, pin-powering of the RTC, a low current MS5803 pressure sensor and an SD card selected for its low-power sleep state. The dashed arrows indicate the estimated run-time to reach the 3.65 V shut-down limit.