White’s Electronics Goldmaster GMT - Manual (Page 7)

5
Chapter 2 GMT Batteries
Battery Check
When the Battery Test toggle is pressed downward,
battery condition is indicated on a bargraph on the
LCD display, and by audio pitch. If the batteries
are not fresh, audio loudness on big targets will not
be as great, but there will be no loss of sensitivity or
performance. Since Nicads and Alkalines die at
different voltages, it is not possible to have a Low
Bat & Bat OK indication, however the bargraph
fills to the right on a fully charged battery pack. As
the battery life drops you will note the bargraph
diminish. When the bargraph gets close to the left it
is time to replace or recharge. At this point the
bargraph changes to a message, "SORRY! LOW
BATT". Typical battery life will be in the neighbor-
hood of 40 hours or more.
Non-rechargeable batteries will start to drop in
voltage as soon as they are put into use and then
slowly diminish in voltage till they die. The Nicad
rechargeable battery pack, however, will diminish
voltage very slowly, in somewhat of a flat line and
then when they begin to lose their charge, the
voltage will drop like a rock. Headphone use pro-
longs all battery life. Battery life will vary a great
deal with temperature, number of target signals,
battery type, brand, and shelf life. Non-rechargeable
batteries may be used until the display indicates
"dead battery", or the audio loudness on large
targets is diminished more than you like. When
traveling far from home it is always a good idea to
carry 8 extra penlight alkaline batteries with you as
well as an extra empty battery holder.
Rechargeable Battery(Opt.)
A rechargeable battery system is not standard
equipment with your GMT, however, high quality
systems are available.
White's rechargeable battery #802-5211, and
charger #509-0022 are recommended and offer
quick charge and overnight charge options.
Rechargeable batteries deliver fairly constant
voltage until they're nearly dead. If you use them
until they are dead, they will deteriorate more
quickly than if you only use them till their voltage
starts to drop significantly. Therefore, recharge-
ables should be taken out of service and recharged
as soon as you notice the battery life starting to fall
substantially below the bargraph position that
corresponds to fully charged batteries.
The White's Rechargeable Nicad battery will not
provide the same amount of continuous use
as a full set of Alkaline batteries.
CAUTION
Battery #802-521
1
SORRY!
LOW BATT
13 12 11.5 11 10.5 10 9.5 9 8.5 8 7.5 7 6.5 6
5
4.5
4
3
2.5
2
1.5
1
0.5
0
3.5
Any voltage reading
less than 8 volts-
charge for 5 hours
maximum on
Quick Charge
setting. Further
charging can
damage the
system.
Charging
Hours
Using the Battery Charger on Quick Charge Setting
Battery Voltage Reading