Delta 4000 Metal Detector - Manual (Page 6)

6
The detector requires a single 9-volt ALKALINE battery (battery not
included). Do not use ordinary zinc carbon batteries.
Rechargeable batteries can also be used.
If you wish to use rechargeable batteries, we recommend using a
Nickel Metal Hydride rechargeable battery.
The battery compartment is located on the back side of the housing.
Slide the battery door to the side and remove it to expose the battery
compartment.
BATTERY LIFE
Expect 20 to 25 hours of life from a 9-volt alkaline battery.
Rechargeable batteries provide about 8 hours of usage per charge.
SPEAKER VOLUME AND BATTERY CHARGE
You may notice the speaker volume drop while one battery segment is
illuminated.
With only the battery outline visible, low speaker volume will be very apparent.
BATTERY INDICATOR
The 3-segment battery indicator has 3 stages of indication.
These indications are accurate for a 9-volt alkaline battery.
Segments Illuminated Battery Voltage
3 -segments more than 8.9 volts
2 -segments more than 7.9 volts
1 -segment less than 6.9 volts
After all segments disappear, expect the detector to shut off within 10 minutes.
A rechargeable battery will usually illuminate 2 or 3 segments throughout most
of its useful charge. But as soon as it drains to the 1-segment level, it will then
discharge very rapidly.
BATTERIES