3
• Never charge the battery unattended. When charging the
battery you should always remain in constant observation to
monitor the charging process and react to potential problems
that may occur.
• After flight, the battery must be cooled to ambient temperature
before charging.
• DO NOT USE A Ni-Cd OR Ni-MH CHARGER. Failure to charge
the battery with a compatible charger may cause fire resulting
in personal injury and/or property damage.
• When flight battery balloons or swells, immediately remove
the battery from service.
If at any time during the charge process the battery begins
to balloon or swell, discontinue charging or discharging
immediately. Quickly and safely disconnect the battery, then
place it in a safe area away from flammable materials to observe
it for at least 15 minutes. Continuing to charge or discharge a
battery that has begun to balloon or swell can result in a fire.
• A battery that has ballooned or swollen even a small amount
must be removed from use immediately.
• Store the battery at room temperature in a dry area for best
results.
• When transporting or temporarily storing the battery the
temperature range should be from 40–120º F. Do not store
battery or model in a car or direct sunlight.
If stored in a hot car, the battery can be damaged or even catch
fire.
• Do not over-discharge the Li-Po flight battery. Discharging
the battery too low can cause damage to the battery resulting
in reduced power, duration or failure of the battery. (See details
below).
Li-Po cells should not be discharged to below 3V each under
load.
In the case of the Li-Po battery used for the Extra 300, you will
not want to allow the battery to fall below 3V per cell during
flight.
Battery Warnings
ONLY
The Extra 300 receiver features a soft low voltage cutoff (LVC)
that occurs when the battery reaches 3V per cell under load.
When the soft cutoff occurs, the electronic speed control (ESC)
and receiver reduce power to the motor (regardless of the
power level set with the throttle stick). This prevents the voltage
of the battery from dropping below 3V per cell.
While it is possible to continue flying the aircraft after the soft
LVC occurs, this is NOT recommended. Battery discharge after
LVC will damage the Li-Po battery, resulting in less power and
shorter flight duration during subsequent flights, or complete
failure of the battery.
Discharging the battery after low voltage cutoff may result in
loss of control. Battery power may drop below the receiver’s
minimum operating voltage so flight controls do not respond
to the transmitter.
Stay aware of the power level of the battery/aircraft throughout
the flight, and when the aircraft requires more throttle than
typical, immediately land the Extra 300.
Note: Battery performance is reduced in cooler temperatures. It
is recommended the batteries are warm before flight.
CAUTION: ALWAYS disconnect the battery from the
aircraft to prevent trickle discharge of the battery. These
batteries require regular maintenance to keep them at a
usable charge level.
Low Voltage Cutoff (LVC)
®