10
Expion360 Battery Manual, G24 and G27
Rev 2
07/18/2022
3
Battery Monitoring
The charge/discharge characteristic curve of a LiFePO
4
battery has a much more gradual slope than lead-acid batteries.
Determining the battery’s state-of-charge (SoC) based on the voltage readings is not the best practice for LiFePO
4
batteries. To accurately calculate the SoC of a LiFePO
4
battery bank, the Expion360 Battery Monitor is recommended.
The battery monitor calculates the SoC based on measuring the current that passes through a finely tuned shunt resistor,
rather than voltage, to give a more accurate reading of the battery bank.
The Expion360 Battery Monitor is easy to program, simple to install, and is compatible with all other brands and battery
chemistries.
It shows the remaining capacity (Ah), SoC (%), battery bank voltage (V), charge/discharge current (A), and
charge/discharge power (W). The battery monitor also shows the remaining discharge time until empty and the
remaining charge time until full. Include this useful accessory for peace of mind, and to see your battery metrics at any
time without manually probing your batteries.
Note that the voltage displayed on the Battery Monitor will read higher or lower than the actual value if the battery has
been charged or discharged within an hour of measurement. Precision will increase with time until 12 hours have passed,
after which the measured voltage will not change. This is not a design flaw, but an inherent characteristic of all batteries
as they are charged and discharged. A greater difference in voltage will be measured when the battery is disconnected
from high current sources/loads than low current sources/loads.
