Campbell CR3000 Micrologger, Operator'S Manual, Page: 104 / 644

Section 7. Installation
104
green CHARGING INPUT connector located on the side of the base. The
charging source powers the CR3000 while float charging the batteries. The
batteries power the CR3000 if the charging source is interrupted. The table
Sealed Rechargeable Battery and AC Transformer Specifications
(p. 105)
lists the
recommended operational temperature range and other specifications.
Leads from the charging source connect to the CHARGING INPUT by way of
two, screw-secured terminals on the connector. Polarities of the leads on these
terminals do not matter. A transzorb provides transient protection to the charging
circuit. A sustained input voltage in excess of 40 V will cause the transzorb to
limit voltage.
A red LED (light) is on the base near the connector. It is illuminated when a
voltage is present at the charge terminals. The charge terminals must be between
17 and 24 Vdc or at 18 V-RMS ac for charging to occur; however, the LED will
also illuminate when the connected voltage is not adequate for charging. The
POWER switch controls CR3000 power. Battery charging continues when the
switch is in the OFF position.
Monitor the power supply using CRBasic instruction Battery(). Incorporating
this instruction into the CRBasic program will enable continuous tracking of
power-supply performance. If the system-voltage level consistently decreases
through time, an element of the charging system is degraded or has failed. The
Battery() instruction measures the voltage internal to the CR3000, not the voltage
of the battery. The measured voltage will be about 0.3 Vdc less than the voltage
at the internal or external 12 Vdc input due to a Schottkey diode. External-power
sources must be disconnected from the CR3000 to measure the battery voltage.
Replacing Sealed Rechargeable Batteries
Replacement of rechargeable batteries may be indicated if the supplied power
shows signs of degrading. See Troubleshooting — Power Supplies
(p. 517).
To replace the batteries, perform the following procedure while consulting figure
Sealed-Rechargeable Battery Wiring
(p. 106).
Install new batteries with the following procedure:
1. Position the power switch on the side of the base to OFF.
2. Loosen the two knurled thumbscrews at the lateral edges of the datalogging
module face.
3. Disconnect the green terminal strips from the wiring panel, if necessary.
4. Carefully separate the datalogging module from the base, unplugging the
white connector that connects the module to the base. The connector is located
just under the lower-left lip of the datalogging module, near the ground lug. A
small lever on the side of the connector must be depressed before pulling it
out.
5. Remove the two batteries and replace with batteries specified in table Sealed-
Rechargeable Battery Specifications
(p. 105).