9
2.6
External Temperature Compensation Connections (Option 11W/11Y)
The natural voltage of a battery changes as a function of temperature change. As the battery temperature rises,
the effective voltage of the battery decreases. Without Temperature Compensation, the battery charger will
always produce a set constant output voltage. As the battery temperature increases, this constant voltage will
then induce a higher output current from the charger. This higher current can result in overcharging the battery,
which in turn can result in damage to the batteries.
Temperature Compensation combats this overcharging by adjusting the charger’s output
voltage based on the
temperature read by the temperature probe. In order to increase the accuracy of the temperature compensation,
the external probe can be used to measure the temperature of the battery.
Option 11W includes the compensation circuit and a 24-foot long temperature probe. Option 11Y includes the
compensation circuit and a 100-foot long temperature probe. With either option, approximately two feet of the
probe is taken inside the charger enclosure.
External Probe Connection Procedure
Before making any connections to the SGC, ensure that the AC Power is off at the main breaker box and that
both of the charger
’s breakers are o
ff. Verify that no voltage is present by using a voltmeter at all input and
output terminals.
To connect the external probe, the JP4 jumper must be moved to pins 2 and 3 on the control board (Refer to the
figure below). Moving this jumper will disable the charger's internal temperature compensation.
On the charger side, simply plug the probe's 3-pin connector in the CN11 connection on the Control/Alarm Board.
Install the remaining lug of the probe to the battery. As battery setups vary between users and battery
manufacturers, it is recommended that the battery manufacturer be consulted for placement of the probe. The
lug of the probe is completely isolated from the compensation circuitry, so the battery voltage will not affect the
compensation.
With the probe connected, enter the Configuration Mode and make sure that Temperature Compensation has
been enabled (For more details, see
Temperature Compensation
under Section 4).
Figure 7
–
External Temperature Probe Connection
(Option 11W/11Y)
