4 Operating From a Personal Computer
64
Operation Guide Flatpack MCU,
351300.013, v8-2006-07
4.11.2.5 Calibrating the symmetry voltage
Calibration of the symmetry voltage needs only one calibration point (at working voltage). The symmetry voltage
should be measured at the battery terminals.
Enter the
Symmetry Voltage
in
Volts
, a figure between 10.00 and 75.00.
Select
Accept
4.11.2.6 Calibrating the battery current
During charging, the battery current is defined as positive (+), during discharge, it is defined as negative (-). In order to
obtain an acceptable degree of accuracy of the current measurement, the current must be calibrated at one low level
point and one high level point. Since the load supply must be maintained, the low calibration current should be
positive, i.e. the current should be measured during float charging while the rectifiers supply both the load and the
battery. The high calibration point should be measured during discharging, while the rectifiers are turned off (or
lowered in voltage). To obtain acceptable accuracy, the high calibration point current should be at least 30 % of the
shunt current capacity.
To calibrate the battery current:
While the system is in float charge mode, measure the shunt voltage and calculate the current
I
shunt
=
V
shunt
/
R
shunt
R
shunt
=
60mV/I
rated
*