METREL MI 3290 - Page 13

MI 3290 Earth Analyser Safety and operational considerations
13
Typical charging time is 3 hours in the temperature range of 5°C to 60°C.
I
ch/8
I
ch
T
LTF
T
COOL
T
WARM
T
HTF
Charge
Suspended
Charge
Suspended
Temperature
Current
Charge
Figure 2.7: Typical charging current vs temperature profile
where:
T
LTF
.................................... Cold temperature threshold (typ. -15°C)
T
COOL
.................................. Cool temperature threshold (typ. 0°C)
T
WARM
................................. Warm temperature threshold (typ. +60°C)
T
HTF
.................................... Hot temperature threshold (typ. +75°C)
The charger continuously monitors battery temperature. To initiate a charge cycle, the battery
temperature must be within the T
LTF
to T
HTF
thresholds. If battery temperature is outside of this
range, the controller suspends charge and waits until the battery temperature is within the T
LTF
to
T
HTF
range.
If the battery temperature is between the T
LTF
and T
COOL
thresholds or between the T
WARM
and
T
HTW
thresholds, charge is automatically reduced to I
CH/8
(1/8 of the charging current).