Sparkfun Battery Babysitter Statistics

The Battery Babysitter communicates using I2C and gives us the following information:

1. State of Charge aka SoC (%)
2. Battery Voltage (mV)
3. Avg Current Draw (mA)
4. Remaining capacity/ Full capacity (mAh)
5. Avg Power Draw (mW)
6. Battery State of Health aka SoH (%)

What this means:

1. The state of charge is the percent of energy available in the battery versus what is available at full charge. This will probably be a useful statistic for us regarding the day and night cycles we have talked about
2. The battery voltage is the voltage difference between the terminals of the battery. Ideally this won't change much for us and will remain constant to a certain degree. The only time I could see this being relevant would be checking if the voltage is high enough to use a certain peripheral and in emergency cases where it is dipping below a defined safe threshold.
3. Avg current draw is what defines how much power we will be using at any given time (from what I read in the documentation I think it is every second). If this value is positive the system is getting charge if it is negative it is discharging. Not sure which statistic will be more useful, this or avg power draw.
4. This tells us both our remaining battery energy and full battery energy in MilliAmp hours. I'm not sure how mAh relates to mWh, but if our voltage is mostly constant then they will scale at the same rate.
5. Avg power draw is just gotten from multiplying avg current draw by battery voltage. Like avg current it is negative if the system is discharging and positive if it is charging. We could measure system power usage with either this or current draw we will have to see if there is a meaningful difference between both approaches.
6. Battery SoH is a subjective percent of what the battery's long term condition is looking like compared to a fresh battery. This might not be relevant at all depending on its rate of decay (if it takes a year to reach 70% then we can't really do much with it), but if we ever want to try and maintain battery health then this could be useful