©2010 Enerdrive Pty Ltd
11
Operation
5.0 Operation
This section explains how the ME-BMK battery monitor works and how to operate
the ME-RC remote control to obtain information on the battery bank. The LCD
displays on the ME-RC related to the battery monitor and the status of the Sense
Module’s LED indicator is also explained in this section.
Info: For information on navigating the remote control, see the ME-RC
Owner’s Manual (PN: 64-0003).
Info: See figure 4-1, METER Menu Map (ME-BMK Displays) for a complete
map of the menu items and adjustable settings available for the ME-BMK
battery monitor using the ME-RC remote control.
5.0.1 How does the Battery Monitor (ME-BMK) Operate? The ME-BMK battery
monitor uses a precision resistor known as a shunt to measure current flow into and
out of the battery. The shunt provides a small voltage to the sense module that
is proportional to the current flow. When current starts flowing into or out of the
battery, the sense module measures the current flow and determines the amount
of current removed from and returned to the battery. The amount of current or
“amp-hours” removed or returned is displayed on the ME-RC remote control as the
AH I/O (Amp-Hours In/Out). The AH I/O number is compensated by a charging
efficiency value that accounts for energy loses while charging and is one of the
factors used to determine the battery’s State Of Charge (SOC).
The battery’s State of Charge - which is the best indicator of the condition of the
batteries - is indicated on the SOC display. This display will show that the batter-
ies are fully charged (i.e. SOC = 100%) only after the following three conditions
have been met:
1. The charging voltage - over a period of time - has stabilized;
2. the charging current has decreased to a low percentage of the amp-hour
capacity - normally less than 2%; and
3. the amp-hours that were removed from the battery are within 1% of fully
being returned;
After the batteries have reached 100% SOC and have discharged ≥ 0.5% of the
battery capacity setting, the charge efficiency value will be recalculated and the AH
I/O readout will reset to the recalculated value.
Info: To help maintain the accuracy of the SOC display and to keep the
batteries in good condition, it is necessary to fully charge them occasion-
ally (approximately once a week).
Info: When charging from a generator (non-inverter topology) and deeply
concerned about the cost of fuel; a balance should be considered between
the use of fuel against charging batteries to 100% SOC to maintain the full
service life of a battery. Batteries discharged to 50% SOC and normally
recharged to 85-90% SOC would be an efficient compromise between fuel
cost and battery life. Trying to restore the last 10-15% for a full battery
charge requires a long time - typically several hours.