CONTROL PANEL
ETV 1591-H
24.03.2015
Page 31
Gray curve
charging current:
While the battery is charging (2): in the flat section of the battery voltage, the battery is
recharged (current 40 mA) although it is already full. This is then a floating charge and
has no disadvantages for the NiMh battery.
5.7
Battery Lifespan and Charge/Discharge Curve
The following chapter contains information on the battery lifespan, self-discharge and infor-
mation on the voltage curve of the battery while charging/discharging.
5.7.1
Battery Lifespan
The battery is charged/discharged according to manufacturer specifications. With the
cyclic charging process used, a battery lifespan of at least 6 years can be ensured.
The battery type used has over chargeable cells. The UPS system implemented limits
the voltage and current, thereby providing double protection for the battery.
With the integrated deep discharge protection (limit 12.3 V), the lifespan is also en-
sured.
If one or several battery cells should still be defective, there is a safety valve to allow
the over pressure in battery to be safely dissipated. The cells are therefore prevented
from exploding.
Since the current in the batter pack is limited via PTC, the battery pack cannot overheat
in the event of a short circuit.
If a short circuit condition exists for too long a time however, irreversible damage can
be caused by deep discharging of the cells (the PTC in the battery is high ohmic, but
the battery will still discharge).