User's Manual

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The power supply circuit is fed by two battery packs, in normal operation a high current main pack will provide the power and in the event of the
failure of the main pack due to a cell being defective, an empty pack, a short circuit, a poor contact within the plug/socket or any other cut the 2nd
battery pack will cut-in. If the receiver switches to the back-up (2nd) battery it will be indicated by the red “Battery” LED on the receiver. For this
reason it is useful if this LED is visible from outside the aircraft and a second LED can be remotely mounted from the unit.
10.2 Battery test function
On switching on, a battery test will be conducted which consists of the main and secondary battery packs being subjected to a 25 msec. 7 Amp load
during which time the packs voltage drop will be measured. If either of the packs drops to below a pre-set value the red “Battery” LED will illuminate
and this will prevent you from taking off with batteries which are not sufficiently charged. Depending upon the type of battery packs used, the warning
voltage can be set as outlined in Para. 12.2.2
The following battery packs can be used:
• 2 Cell (2C) Lithium Polymer Batteries nominal voltage 7,4 Volt, minimum current rating 20 C. minimum capacity 2500 mAh
• 3 Cell (3C) Lithium Iron Phosphate Batteries (A123 Cells), nominal voltage 9,9 Volt
• 6 Cell NimH Batteries, nominal voltage 7,2 Volt, minimum size SUB C
All weatronic battery packs are of high quality high current draw packs with the lowest internal resistance. They are all fitted with silicon wire and
Multiplex high current plugs. You may of course use battery packs from a 3rd party providing that they meet the required specifications and quality.
On no account should AA of Eneloop type cells be used. To be on the safe side we strongly recommend that you use packs
which are currently favoured by pilots flying with the current breed of high power brushless systems.
10.3 Selecting a battery with the correct capacity
When choosing batteries for your system, the capacity of the main battery pack is most important factor and if necessary packs should be connected
in parallel to achieve sufficient capacity. The nominal voltage should be between 7.2 and 10.0 volts. For the secondary pack 2000 mAh will normally
be sufficient as this pack will only be required to power the model for 1 flight + 100% for a safety margin. The red LED will warn you of a problem
with the main battery pack (see Annex 2 for blink codes) giving you a chance to solve the problem or to re-charge the pack
We recommend battery packs with the following capacities:
• Acrobatic models with a wingspan of 3 Meters and 9-12 high current digital servos:
Main pack: 4000 - 6000 mAh
Reserve pack: 2000 - 4000 mAh
• Acrobatic models with a wingspan of 2.5 Meters and 7-10 high current digital servos:
Main pack: 3000 - 4000 mAh
Reserve pack: 1500 - 2000 mAh
• Medium sized jets:
Main pack: 3000 - 6000 mAh
Reserve pack: 1500 - 2000 mAh
• Large jets or scale model with many functions and features:
Main pack: 4000 - 8000 mAh
Reserve pack: 2000 - 4000 mAh
10.4 Caring for battery packs
Caring for your battery packs correctly is vitally important! Failure to do so can lead to a failure of the on-board electronics with catastrophic results,
which may not only be dangerous but will also be very expensive! Although the chances of suffering a failure of 2 packs is considerable less than
when flying with only one pack, you should still take great care over the choice and maintenance of your battery packs. Disregarding pilot error
battery failure is one of the main reasons for aircraft crashing. For safety reasons weatronic recommend the use of high quality battery packs which
are charged with and maintained by a good quality micro processor driven charger.