OHAUS CKW-55, Service Manual

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3-9
CHAPTER 3 INDICATOR TESTING
3. Note the charging status of the battery. If the red bar graph is lit, either the battery and or the
charging PCB has failed.
Note : To force a charge cycle, see section 3.5.1.
4. Press the C button momentarily, the Indicator will display the actual battery voltage.
Approximately 6.1 Volts dc or lower indicates a discharged battery, 7.2 Volts is the nominal
battery voltage and approximately 8.5 Volts dc is the maximum charge voltage. Before
replacing the battery, force a charge cycle and allow the Indicator to remain plugged in for
several hours and check the battery voltage by pressing the
C button. If the bar graph indicator
for battery status fails to light or advance, refer to testing of the Recharge Board, see section
3-5.
5. After recharging the battery, remove AC power from the Indicator and operate the Indicator
using battery power to determine if the battery retained a full charge. A new battery should
function for at least 10 hours. When the battery operates the Indicator for less than 5 hours,
it should be replaced. See section 4.8 for battery replacement procedures.
Note : The power save function should be turned off to allow testing battery life.
3.4.2 Troubleshooting the Battery (Cont.)
6. The battery contains a monitor chip that can be accessed to determine the battery temperature,
voltage, number of charge cycles and present charging state.
To access data on the battery monitor chip, connect an RS232 cable to the Indicator and a
PC. The Indicator should be powered on with ac power. Send the following serial commands,
(<esc>SV) followed by the Battery dump command, (<esc>BD). The indicator will output
a text string containing the battery voltage, battery temperature, number of charge cycles, and
the present charging state. See Appendix A.1 for more details.
Example shown on the PC screen: 8.22v 24C 1CC 2. The 8.22v indicates the battery
voltage, 24C indicates the battery temperature, 1CC indicates the number of complete charge
cycles and 2 indicates the present charging state. (See 3.5.1 for charging information).
7. If the battery fails to produce any voltage, it must be replaced.
Figure 3-6. Battery and Recharge Board Location Diagram.
. .