CONTROL PANEL
ETV 1591-H
24.03.2015
Page 29
5.6
Battery Charging Process
According to the battery manufacturer's recommendation, the following cyclic charging
process is used with circa C/20 charging rate to maximize the life span of the battery.
A charging rate of C/20 corresponds to 1/20 of the battery capacity (1100 mAh / 20 = 55
mA)
This is the typical charging rate for long-term charging processes of NiMH batteries.
The battery charging circuit is activated:
If the main supply is on. A 24 h continuous charging cycle is started.
After a charging pause of 24 hours. After the first 24-hour charging cycle, the sys-
tem switches to a pulsed charging cycle and every 24 h, an 8-h continuous charg-
ing cycle is performed to maintain the voltage (see image 1 & 2).
The charging circuit is deactivated:
If the device is powered by the battery (main voltage supply failure).
If the actual charging time (24 h / 8 h, see image 1 & 2) is exceeded.
The charging current falls to <= 30 mA.
5.6.1
Time Specification
Example of the time response of the charging circuit with a continuously powered ETV
1591-H:
Image 1
1
Start of 24 h charging by turning on the main supply
2
24 h battery charging
3
24 h charging ended
4
24 h charging stop
5
Start of 8 h charging after 24 hour charging stop (pulsed charging)
6
Start of 8 h charging after 24 hour charging stop (pulsed charging)