on. The powercontrol circuit inside the instrument manages battery charging
and will stop charging the battery automatically when it’sfully charged. It nor-
mallytakes about four hours to fully charge the battery. The instrument can be
operated while the battery is being charged.
CAUTION:DO NOT leave the AC adapter plugged in for more than 24
consecutive hours or, the battery life could be degraded.
The battery pack can be used for aminimum of 500 charge-discharge cycles
before needing to be replaced. Replacement battery packs are availablefrom
the manufacturer.The battery pack can be easily removed and replaced in the
fieldby following this procedure:
1. Power the 1521 off and unplug the AC adapter from the unit.
2. With the 1521 facing down, lift the stand to expose the battery cover (see
Figure 4). Remove the battery cover screw with a small Philip’s screw-
driver. Place the screw in a safe place so it won’t get lost. Remove the
battery cover to access the battery pack.
3. Pull the battery pack out. Note the orientation of the battery plug on
the connector.The new battery pack will be plugged in the same direc-
tion. Gently pull the battery plug off the connector.
4. Attach the polarized plug of the new battery pack onto the connector in
the same direction as before (see Figure 4 on page 19). Place the battery
pack in the battery compartment.
5. Close the battery cover and replace the screw.
6. Plug in the AC adapter and charge for a minimum of four hours for its
initial charge.
WARNING:Used batteries must be disposed of properly. Check your lo-
cal regulations for additional information. You may return used batteries
to the manufacturer. Never dispose of batteries in fire as this may result in
explosion with the possibility of personal injury or property damage.
6.2 DC Power Source
The DC powersource provides power to charge the battery. It can also be used
to powerthe 1521 while the battery is being charged. The AC adapter provided
withthe 1521 is intended to be used for these purposes. Use only the AC
1521 Handheld Thermometer Readout
User’s Guide
20