How to fly RC aircrafts


Lithium Polymer (LiPo) Battery FAQ

Lithium Polymer Batteries is the favoriteeach charge and would also result in a
power source of electric radio-controlleddiminished  performance  of the battery pack.
models. They are relatively cheap, light, and
hold lots of power. However, many newA balance charger eliminates any
hobbyists may have some enquiries as to theirunbalanced-cells symptoms of a battery pack
operations.by charging each cell individually; making
sure that the cell's voltage remain balanced
Here are three frequently asked questionsat the end of each charge. In essence,
about  them.balance charger lengthen the life of the
battery back and maximizes its performance as
1.  What  is  Cell  Balancing?well as keep the pack stable and safe to
operate.
Lithium Polymer batteries usually come
packaged as a pack of more than two2.  What  is  C  rating?
individual battery cells. For example,
electric RC helicopters use 3-cell packs.A lot of radio-control fliers quickly grasp
Each of these battery cells has a nominalthe meaning of most of the battery-associated
voltage of 3.7v; which means that each cellacronyms but one: the C rating. In fact, many
can operate when it maintains its chargeexperts have tripped over themselves trying
between 3.0 to 4.2v. To go above or below orto explain it. However, I've heard a
below this range can damage the cell andgraspable explanation of it from an old
render it useless, or worse, becomeChinese battery manufacturer/expert very
dangerously  unstable  and  explode.recently. Which is: The "C Rating" is the
number which you multiply to the capacity of
While the battery is in usage, the powerthe  battery  to  get  its  discharge  rate.
drawn out of each cell is not equal.
Therefore, at the end of each flight, theStill confused? Basically, a 1000 mAh battery
cells in the battery will be left out ofrated at 1C will provide 1000 mA of power for
balance. A non-balancing charger will stop1 hour. On the other hand, if the same pack
charging the battery pack once the voltage ofwas rated at 2C, it would provide 2000 mA of
the overall pack is full without paying anypower  for  30  minutes.
attention to each cell. This causes the
battery to be more and more unbalanced with3. How fast can I charge a pack?



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