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  • Author Author: fvan
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Quadcopter Charge Notifier using Particle Photon

fvan

I received my first quadcopter for Christmas, a XS Nano Quad from Revell. It’s a tiny quadcopter, which I find extremely fun to play with. Unfortunately, the battery lasts only about 5 minutes (3.7V 100mAh) and the charge time is between 30 and 40 minutes.
Because I regularly forget I put it to charge, I decided to make a simple device which can notify me as soon as the battery is fully charged, allowing me to maximise play time!

 

Using a Particle Photon and a photoresistor, changes in light intensity from the charge indicator LED can be measured and used to trigger a notification via the IFTTT service.

imageimage

As usual, all details including code are available on my blog: Quadcopter Charge Notifier using Particle Photon – Frederick Vandenbosch

 

Let me know what you think! What would you use such a notification system for?

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  • in reply to tomaja

    LiPo batteries are usually declared as capable of 1C charge

    Not quite.

     

    1C is the recommended discharge rate, and sometimes they have electronics that disconnects if it's exceeded.

    LiPo (and any Lixx) battery have varying methods of charging, but ultimately for most batteries you usually need about 140% of the battery capacity to recharge it.

    So a 100mAH battery can be discharged at 100mA for 1hour

    You 5 min run time is probably 75% discharged which is works out at around 12C or 900mA drain.  

     

    There is much more info here.

    http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

     

    I suspect the 30-40 mins is to err on the safe side, and allow the motors to cool.

    I have one that plugs into the USB socket on a computer.

     

    Lithium batteries can catch fire if overcharged (the easist way to put them out is cover with sand).

     

     

    Your idea is a great way to prolong the life, and these toys do become addictive.

     

    Mark

  • in reply to mcb1

    I use LiPo (not Li-Ion) batteries regularly for my RC multi rotors and airplanes. Most of them are rated at least 20C discharge and none of them includes built-in electronics.

    For example, one of my 3 cell batteries is rated 30C with capacity of 2200mAh. Three motors on my tricopter draw ~45A when run at full speed (that's ~20C discharge for that battery).

    Yes, Frederic's battery is being discharged at around 12C. And, yes, it takes more than 100mA for 1h to push 100mAh into battery that's why I included the "~" sign image

     

    I don't see what wrong with what I said about 1C charge rate.

    Google search returns this:

    image

  • in reply to tomaja

    Google search returns this:

    And who/what did they reference to.?

     

    I was fortunate to have also had a battery guru give our club a talk on Lixx batteries.

    The do's, don't's and myths were all covered and he did admit that it was embarrasing how much of the below site he knew from his experiences/eduction.

     

    http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

    Increasing the charge current does not hasten the full-charge state by much. Although the battery reaches the voltage peak quicker, the saturation charge will take longer accordingly. With higher current, Stage 1 is shorter but the saturation Stage 2 takes longer. A high current charge will, however, quickly fill the battery to about 70 percent.

    Apparently it's not the rate of charge but the final voltage that counts, and regardless of the rates full charging takes around 2C.

     

    He also decribed any charged Lixx battery as a Hand Grenade, and how far the the pin was pulled was relative to how close to the maximum voltage the cells were designed for.

     

     

    You are right that any battery designed to be discharged above 1C will not have electronics.

    These need to be treated with care, especially if they suffer a major G force shock.

     

    Mark

  • in reply to mcb1

    I think I understand your point, thanks.

     

    Dragan

  • in reply to tomaja

    More inprotant than charge times is the amount  current wich you safely can draw. In LiPo batteries 1C acually means that you can charge or discharge a 1 Ah battery with 1 Amp.

    The not physically correct formula is (ignoring all units):

    capatcity (in Ah) * C = current (i A)

    In my bigger (300er) heli I fly a 1,8 Ah battery wich is rated at 30C. That gives the little thing 54 Amps to play with image (at 11,7 V)

    But for bigger RC helis 90C at 22 V is not unusual.

    I don't know why the batteries behave assymetrical, i. e. discharge much faster than they charge.