This is the SOC or State-of-charge screen. This screen is the best way to monitor the SOC of the battery with this monitor. This screen is only useful provided you have programmed the monitor correctly, it's synchronizing the way it should and is wired properly. This readout calculates the amount of energy available in the battery and is Peukert & CEF / Charge Efficiency corrected. The screen ranges from 0% = dead to 100% = full.
Counting amp hours is ok but may not always reflect the true state of charge of the battery. For example if the battery is drawn down heavily & at a high rate of current you will get less usable Ah's than its rating. If drawn slower than the 20 hour rating you can get more Ah's out of it. The SOC screen corrects for the Peukert component and CEF the Ah screen does not.
Please take the time to read the manual for these monitors as they are generally more difficult to program and master than the actual installation!