{"id":60,"date":"2021-07-03T07:20:42","date_gmt":"2021-07-02T21:20:42","guid":{"rendered":"http:\/\/inkthemes.com\/wptheme\/rc-airplanes-class-wordpress-theme\/?p=60"},"modified":"2021-07-11T17:32:14","modified_gmt":"2021-07-11T07:32:14","slug":"electric-rc-airplanes","status":"publish","type":"post","link":"https:\/\/wrcs.org.au\/WP1\/electric-rc-airplanes\/","title":{"rendered":"How to determine a Model’s Electric Power Requirements"},"content":{"rendered":"

 <\/p>\n

1. Power can be measured in watts. For example: 1 horsepower = 746 watts
2. You determine watts by multiplying \u2018volts\u2019 times \u2018amps\u2019.<\/p>\n

Example: 10 volts x 10 amps = 100 watts<\/p>\n

Volts x Amps = Watts<\/strong>
3. You can determine the power requirements of a model based on the \u2018Input Watts Per Kg\u2019 guidelines found below, using the flying weight of the model (with battery):<\/p>\n

\u2022 155-200 watts per Kg; Trainer and slow flying scale models
\u2022 200-245 watts per Kg; Sport aerobatic and fast flying scale models
\u2022 245-285 watts per Kg; Advanced aerobatic and high-speed models
\u2022 285-330 watts per Kg; Lightly loaded 3D models and ducted fans
\u2022 330-440+ watts per kg; Unlimited performance 3D models<\/p>\n

NOTE:<\/strong> These guidelines were developed based upon the typical parameters of E-flite motors. These guidelines may vary depending on other motors and factors such as efficiency and prop size.<\/em><\/p>\n

4. Determine the Input Watts per Kg required to achieve the desired level of performance:<\/p>\n

Model: Hangar 9 P-51 Miss America
Estimated Flying Weight w\/Battery: 4.1 Kg
Desired Level of Performance: 200-245 (220 average) watts per Kg; Fast flying scale model<\/p>\n

4.1kg x 220 watts = 902 Input Watts of power (minimum) required to achieve the desired performance<\/strong><\/p>\n

    \n
  1. Determine a suitable motor based on the model\u2019s power requirements. The tips below can help you determine the power capabilities of a particular motor and if it can provide the power your model requires for the desired level of performance:
    \u2022 Most manufacturers will rate their motors for a range of cell counts, continuous current and maximum burst current.
    \u2022 In most cases, the input power a motor is capable of handling can be determined by:<\/li>\n<\/ol>\n

    Average Voltage (depending on cell count) x Continuous Current = Continuous Input Watts<\/strong>
    Average Voltage (depending on cell count) x Max Burst Current = Burst Input Watts<\/strong><\/p>\n

    HINT:  The typical average voltage under load of a Li-Po cell is 3.3 volts. This means the typical average voltage under load of a 10 cell Ni-MH pack is approximately 10 volts and a 3 cell Li-Po pack is approximately 9.9 volts. Due to variations in the performance of a given battery, the average voltage under load may be higher or lower. These however are good starting points for initial calculations.
    Model: Hangar 9 Miss America
    Estimated Flying Weight w\/Battery: 4.1Kg
    Input Watts Per Kg Required for Desired Performance: 200 (minimum)<\/p>\n

    Motor: Power 60
    Max Continuous Current: 40A*
    Max Burst Current: 60A*
    Max Cells (Li-Po): 5-7
    6 Cells, Continuous Power Capability: 19.8 Volts (6 x 3.3) x 40 Amps = 792 Watts <\/strong>
    6 Cells, Max Burst Power Capability: 19.8 Volts (6 x 3.3) x 60 Amps = 1188 Watts<\/strong><\/p>\n

    Per this example, the Power 60 motor (when using a 6S Li-Po pack) can handle up to 1188 watts of input power, readily capable of powering the P-51 Miss America with the desired level of performance (requiring 902 watts minimum). You must however be sure that the battery chosen for power can adequately supply the current requirements of the system for the required performance. You must also use proper throttle management and provide adequate cooling for the motor, ESC and battery.<\/p>\n

     <\/p>\n\n\n\n\n

    <\/p>\n","protected":false},"excerpt":{"rendered":"

    Without doubt electric rc airplanes (electric power or ‘ep’) have been responsible for bringing <\/p>\n","protected":false},"author":1,"featured_media":61,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-60","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-electric-power-planes"],"_links":{"self":[{"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/posts\/60","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/comments?post=60"}],"version-history":[{"count":9,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/posts\/60\/revisions"}],"predecessor-version":[{"id":886,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/posts\/60\/revisions\/886"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/media\/61"}],"wp:attachment":[{"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/media?parent=60"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/categories?post=60"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wrcs.org.au\/WP1\/wp-json\/wp\/v2\/tags?post=60"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}