Radio Shack PRO-67 Operation page 24

4. Install two fresh batteries in the compartment and two in the cover as
indicated by the polarity symbols (+ and -) marked inside the
compartment and cover.
Cautions:
Use only fresh batteries of the required size and type.
Always remove old or weak batteries.
that destroy electronic circuits.
Do not mix old and new batteries, different types of batteries
(standard, alkaline, or rechargeable), or rechargeable batteries of
different capacities.
5. Replace the cover.
If BATT Lo flashes on the display and the scanner beeps every
15 seconds, replace all alkaline or general purpose batteries or
recharge all rechargeable nickel-cadmium batteries.
Caution:
Always dispose of old non-rechargeable batteries promptly and
properly. Do not bury or burn them.
Charging nickel-cadmium Batteries
The scanner has a built-in circuit that lets you recharge nickel-cadmium
batteries while they are in the scanner.
ALKALINE <- JACK -> NI-CD to NI-CD, install the nickel-cadmium batteries
in the scanner, and connect an external AC or DC adapter to the scanner's
POWER jack.
Warning:
Do not connect either adapter to the scanner if non-rechargeable
batteries (such as standard, extra-life, or alkaline batteries) are
installed in the scanner and ALKALINE <- JACK -> NI-CD is set to NI-CD
or you are unsure of the switch's position.
batteries will get hot and can even explode if you try to recharge
them.
Before you use nickel-cadmium batteries for the first time, charge
them at least 24 hours to bring them to a full charge.
Discharged batteries take about 10 to 18 hours to fully recharge.
The charging time is lengthened when you operate the scanner while
recharging nickel-cadmium batteries.
Notes:
Nickel-cadmium batteries last longer and deliver more power if you
occasionally let them fully discharge.
scanner until it begins beeping every 15 seconds and BATT Lo flashes
on the display.
Batteries can leak chemicals
To charge the batteries, set
Non-rechargeable
To do this, simply use the