Samlex America SEC-2440UL - Manuel (Page 23)

22 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 23
seCtIOn 7 | Preparing the Charger for Operation
teMPeRAtURe coMPenSAtion
The cell voltages of a battery depend upon the temperature of the cells inside the bat-
tery. The cells have a Negative Temperature Coefficient - their voltage levels increase
at lower temperature and decrease at higher temperature. The Negative Temperature
Coefficient is - 2.5 mV / ºF / cell or - 15.0 mV / ºF/ 6 cells for a 12V battery or -
30.0 mV / ºF / 12 cells for a 24V battery.
The battery and battery charger voltages are normally specified at a temperature of
77ºF (25ºC). Thus, if the battery temperature is considerably lower than or higher than
77ºF, it will be under-charged or over-charged unless the battery charger has tempera-
ture compensation.
teMPeRAtURe SenSoR PRoBe tF-500
This charger has a provision for temperature compensation. A temperature sensor unit -
Model No. TF-500 (Fig. 7.3) is provided for this purpose.
Fig. 7.3. Temperature Sensor Model No. TF-500
!
cAUtion!
This temperature sensor is matched and calibrated for each battery charger and
should not be interchanged with the sensor from another battery charger.
The temperature sensor comes with 5 Meter cable. It has a plug on one end. Connect this
plug into the jack marked TS (4) on the rear panel of the charger. The other end has the
temperature sensor element. Mount this temperature sensor element flush with the side
surface of the battery for proper heat transfer.
When the temperature sensor is connected, the voltages during Stages 2 and 3 are
automatically adjusted as per the temperature of the battery and the above temperature
coefficient.
Plug
Temperature
Sensor Element