resistor. Don't try
to
read the voltage at the output of the
charger because you'll end up reading the voltage
drop
through all the connectors and cables between the
charger and the Ni-Cd pack, which can sometimes distort
the effect you're looking for. You should start with a Ni-Cd
pack that is less than half charged. Connect your charger
and begin charging at four amps. If your charger is
adjustable, set the current
now-but
don't try to change it
later. A constant current charger is preferable here, but if
yours gradually drops off during charge, that's still permis-
sible, as long as it doesn't drop below three amps.
Watch the voltage as the
pack
charges. Notice
that the voltage at first climbs rapidly and in the middle of
the charging cycle more slowly. This voltage will most
likely
be
in the range
of
8 1/2 to 9 volts for a six cell pack.
As the
pack
approaches full charge, the voltage will begin
to climb more rapidly; and as it goes into overcharge, the
climb will slow down and then stop. This is where you stop
charging-at
the point where the voltage stops climbing.
If you left the charger on, the voltage would begin
to
fall as
the
pack
went deeply into overcharge and started to heat
up. The maximum voltage reached will probably
be
in the
nine
to
ten volt region; the actual value
is
unimportant.
When measuring voltage
on
NiCad cells, you
must use a digital VOM (volt/ohm meter). A conventional
analog scale VOM
is
not sensitive enough. By the time you
see the needle move across the scale, you would have
already damaged the battery cells.
SLOW CHARGE METHOD. Slow
or
"overnight"
charging is a method you are not likely to use often, but it
is a
good
way to bring the
pack
to absolutely full charge.
However, the output voltage of a slow charged
pack
is
slightly lower.
The charging current must be between 0.05 and
0.12 amperes. If less current, the pack will never reach full
charge; any more and the pack will overheat. The time
required
to
reach full charge ranges from 15 to
40
hours,
depending on the current used. The charger can
be
Iefton
for a
much
longer time without harming the cells; however,
the output voltage of the pack will be temporarily lowered
by
an extremely long overcharge. The voltage returns to
normal after a discharge-charge cycle.
These next two tips are really for the benefit
of
serious
racers. If you're just out having fun,
don
't worry about
them.
FULL DISCHARGE. Ni-Cd packs perform best if
they are COMPLETELY
discharged
before they are
charged. If you
are
involved
in
racing, you will have to do
this if you expect to win any races! Discharge for at least
an
hour (preferably overnight with a clip-on resistor)
before charging.
Associated Chargers have a discharge function. Various
clip-on discharge resistors (about
30
ohms, 10 watts) are
available at hobby stores.
TOPPING-UP can
give
you a little extra voltage at
the beginning of a race, as long as you don't overdo it. Put
the last minute
or
two
of
charge
into your pack just before
the race starts.
GOOD LUCK
IN
YOUR RACING!
CAUTION
Ni-cad batteries are susceptible to damage when over-
charged at a high rate, and
can
release caustic chemicals
if the overcharge
is
severe.
Do not stall the motor under power. If the truck stops
suddenly on the track,
or
fails
to
move forward when you
attempt to accelerate, push the throttle control
on
your
transmitter to the brake position immediately and attend to
the truck. A small rock
can
stall the gears, and
if
the throttle
is left in the on position the result can
be
a burned
out
motor
(or electronic speed control unit).
If you run your truck to the point where more than one cell
in the
pack
is completely discharged, it is possible to lose
radio control
of
the truck before the drive motor stops
completely.
For
this reason you should not operate your
truck in an area where it could
be
harmed or cause harm,
such as near a busy roadway
or
a pool
of
water. Usually
radio control will be regained as soon as you pick up the
truck and the motor is allowed to free-run. If you still don't
have control, then you should unplug the motor.
When you stop running your truck, turn off the radio at the
truck first before turning off the transmitter.
'
A burned-out
or
shorted motor can make the truck
appear
to have radio problems. If the truck slows down suddenly
and the radio acts erratically even with a full battery
charge, then the cause is probably the motor. Check the
range of the radio with the motor unplugged. A shorted
motor will
draw
extremely high current even under no-load
conditions.
SAVE
THIS
BOOKLET!
MORE
THAN
AN
INSTRUCTION
MANUAL,
IT'S
ALSO
A
HANDY,
PICTORIAL
SUPPLEMENT
TO
TEAM
ASSOCIATED'S
RCfOT
CATALOG.
REFER
TO
THIS
MANUAL
FOR
PART
NUMBER
AND
NAME
WHEN
ORDERING.
page 46
To Previous Page
Loading...
