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May
2015
WorkHorse H-ADCP Operation Manual
Page 78
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Replacing the H-ADCP Lithium Battery
This section explains how to replace the rechargeable lithium coin-cell battery in a H-ADCP system. The
battery is located on the CPU board just below the PIO board transmit capacitors. The battery will re-
charge itself as soon as power is applied to the H-ADCP. Over time, the battery loses the ability to re-
charge and the voltage capacity drops. Therefore, TRDI recommends replacing the battery every five
years.
The battery keeps the Real-Time Clock (RTC) running
in case power is removed temporarily. The
RTC drifts independently from the battery voltage by approximately 12 minutes/year. Clock drift
does NOT indicate problems with the battery.
Equipment Required
•
ESD safe work space
•
Soft pad (ESD Safe) to rest H-ADCP on while dissembling and reassembly
•
Anti-static ground strap
•
Hex wrenches
•
O-rings and desiccant for H-ADCP
•
Soldering iron
•
Digital multi-meter
•
Lithium battery VL2330
Testing the Lithium Battery Voltage
To verify that the lithium battery is working:
1.
Remove the transducer head assembly
2. Measure the voltage on the CPU board between TP17 (BAT+) and TP20 (GND). While power is
not applied to the H-ADCP, TP17 should read approximately 3 VDC and the voltage should re-
main stable (see Figure 38).
3. If the voltage is below 3 VDC and visibly decreasing, then reapply power to the H-ADCP. While
recharging, TP17 should read approximately 5 VDC. This only takes a few seconds.
4. When the battery is done recharging, the voltage should read slightly above 3 VDC with power still
applied.
5. After recharging the battery, disconnect the power and test the voltage. The voltage should hold
stable at approximately 3 VDC for several hours at least, but for best results it should hold at 3
VDC for several days.