Quads for Fun
Your #1 Source for Drones and Quadcopters Reviews
November, 2016 News
LITHIUM POLYMER BATTERY: there are huge variety of batteries available for Quads. The desirable combination of specs should be: low budget, correct size, less weight, longest flight times and correct voltage-amp (power).
CAPACITY (mAh) is the main number shown on battery label. It’s measured in mAh (Milliamp/hour). Keeping simple terms, a 2100 mAh battery will run for twice as long as a 1000mAh battery. Batteries have different sizes, plugs, wire and charge rates.
DISCHARGE (C) is the amount of power the battery can push out. It’s direct linked to the power level required of the motors. A higher “C” rated battery will last longer if run at a lower rate. Example - a 30C battery run at 20C maximum will have a longer cycle life than a 20C run at 20C each flight.
VOLTAGE (V): Li-Po cells have a nominal voltage of 3.7v per cell. Fully charged should be 4.2v and when discharged, never be below 3v. The Li-Po batteries are made up of layers of multiple cells. A 3S battery means it’s 3 x 3.7v = 11.1v.
WEIGHT AND SIZE: a right battery must fit within the battery compartment of the quad and balance the plane correctly. For beginners, it is tempting to choose the biggest and most powerful battery the model can handle. But it will sacrifice flight performance and worst, if the battery voltage is too high it will destroy the ESC or motors. Check the ESC and motor specification to ensure right voltage pack and then, check the models center of gravity (CG) to decide on the right battery weight.
LI-PO CHARGING: never charge the battery above 4.2v per cell. Li-Po cells should not be discharged to below 3.0v. Li-Po batteries are significantly more volatile than the alkaline, NiCd or NiMH batteries also used for drones. Then, charging Li-Po batteries can result in fire. Do it in a safe area away from flammable materials and never unattended. Monitor the charging process. After flying and discharging the battery, allow it to cool to ambient temperature before recharging. To charge the battery, use only the correct and suitably compatible USB cable or an specific Li-Po battery charger. Discharging the battery too low can reduced power, flight duration or failure entirely. If suddenly the unit begins to require more throttle than typical to maintain hover, you should land the Quad and disconnect the battery immediately.
FLIGHT TIME VERSUS BATTERY CAPACITY: using simple words, larger battery allows for longer Quad flight time. But the increase of flight time isn’t proportional to the increase of battery size (see diagram). As the battery gets larger, the increase in flight time becomes ineffective. It will reach a point where it just doesn’t gain any more flight time or even, lose it. This is mainly caused by the weight of the battery. Reducing weight is, indeed, the biggest key to extending flight times. Then, bigger and flatter propellers, higher- torque and lower-kv motors are other keys. But there are lots of other factors that contribute to reduce the Quad flight time. A few of them are wind speed, temperature, aerobatic maneuvers (flips and rolls), electronic components, quality of the link between Quad and transmitter. There are so many variables that it is almost impossible to specify exactly how long the quad will fly. Manufacturers use a time range to define the flight time. But this time is not always true and accurate fact. Thus, it can range from 5 to 25 minutes on Quads used for fun. Professional quads are a different story.
RTF (Ready-to-Fly): the model comes complete, nothing is needed to get started.
BNF (Bind-N-Fly): products come without the transmitter. Use own transmitter. Bind it to the receiver.
PNP (Plug-N-Play): product comes with everything, except: transmitter,receiver, battery and charger.
ARF (Almost-Ready-to-Fly): the model needs some additional items before you can start flying.
See infromation on the box label.