Sainlogic FT0300 User Manual page 6

Close the battery cover. Make sure the gasket (around the battery
compartment) is properly seated in its place prior to closing the door.
Tighten the set screw.
Note: Do not install the batteries backwards. You can permanently
damage the sensors. The solar panel does not charge the batteries, so
rechargeable batteries are not needed or recommended.
Note: We recommend installing Lithium AA batteries for sensors.
The sensor LED indicator will light for 3 seconds, and then flash once
per 16 seconds thereafter. Each time it flashes, the sensor is
transmitting data.
Place the battery cover and push it to close the compartment.
Note: If the sensor does not power up after inserting the batteries,
press the reset button shown in Figure 6.
3.3.2 Insert batteries into the thermo-hygrometer
transmitter.
removing the set screw, as shown in Figure 7.
Remove the battery cover on the back of the sensor by
Figure 6
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