Electric flight - the best and worst of Li-Po

Seen those great looking model airplanes whizzingevery volt it receives from the battery. In other
around the park recently - but without the noise?words, a 1000kvm motor is capable of 7400 RPM
Whatever happened to that mosquito snarl? Discoverwhen using a 7.4v Li-Po, and 11,100 RPM when using
the impact that Li-Po is having, the most recentan 11.1v Li-Po. This information, combined with the
advance in power for electric model airplanes.prop type and weight of the plane gives you all the
Discover how to calculate their normal and maxdata needed to calculate the final thrust output of a
power as well as their endurance - and a safetygiven motor.
warning. What happened to that mosquito snarl thatThe amperage rating of Li-Po batteries is rated in
always seemed to accompany the sight of modelmilliamp hours (mAh). This technical term describes
airplanes? The answer is they're going electric andhow long the Li-Po will provide electrical power in
silent. Li-Po (Lithium Polymer or Li-Poly) batteries aremuch the same way that the size of the fuel tank
rapidly becoming the standard power source foron a glow powered airplane will dictate how long the
electric model airplanes. Li-Po batteries are smaller,engine can keep running. Typical electric RC model
lighter and hold more power than their predecessorsairplane flights can last 20%-50% longer when using
(Nickel Cadmium and Nickel Metal Hydride). There areLi-Po compared to other batteries. The larger the
three specifications that need to be taken intomAh rating, the bigger and heavier the battery will
consideration when making a Li-Po battery purchasebe. This is a major factor to take into consideration
for your electric model airplane.when putting together any electric RC model aircraft.
The voltage of the battery will tell you how powerfulLi-Po battery burst rates describe the output
it is, the amperage rating will give you an idea howcharacteristics of the battery. Burst rates tell you
long it will last, and the burst/constant power ratinghow much power the battery is safely capable of
will tell you how quickly the power will discharge. Adischarging in one big burst. This number is often
major difference between Li-Po batteries and othershigher than the constant power rating. Once the
available for RC model airplane use is that it is muchburst of energy has been discharged, the constant
easier to mistreat the battery thereby creatingpower rating tells you where the power output will
unsafe situations the consequences oc which can besettle down to.
dramatic. Li-Po batteries can be very dangerous ifLi-Pos come with very strict safety guidelines that tell
you don't follow all of the safe handling proceduresyou how to care for them. Charging rates, charging
set out by the battery manufacturers.times, and damaged battery disposal procedures just
In most cases, Li-Pos used for model airplanes cometo name a few. Damage to your RC electric model
in two voltage ratings ratings; 11.1v and 7.4v. Theairplane can be avoided by following these guidelines.
rating dictates how many volts the battery willProperly matched brushless motors and Li-Po
discharge to your brushless RC motor. Electric RCbatteries can provide hours of clean and quiet flying
model aircraft motors themselves have ratings thatenjoyment. Take the time to understand everything
relate to this voltage discharge specification. Thethat's involved with a Li-Po setup and you will have
voltage of a Li-Po battery is directly tied to the RPMmore fun and more time in the sky with your electric
output of a brushless motor in that a motor ratedmodel airplane.
for 1000kvm will rotate 1000 times per minute for