Syma X5HW sees all batteries as drained but they are not

[Oleg]

Good day!
My Syma X5HW recently started behaving strangely.
I put a fully-charged battery in it, start flying and get flashing "low battery" lights in 10-20 sec of flying. After 1 more minute it decends or falls down as usual when battery is fully drained.
I thought that old batteries were the reason (and even bought a couple of new!) but today while flying together with my friend he gave me his battery - i started flying and same situation occured again - 10-20 sec and "low battery" warning.
After that we put this "drained" battery back to my friend's copter (also X5HW) and it showed that battery is normal, no blinking lights and its possible to fly further.

So after that I understood that the problem is in the copter itself, not the batteries. What can it be and how to fix it? Capacitor? Change receiver chip? Buy new quadcopter?

Thank you!

 

[Rick M]

You should be able to buy the board pretty cheaply if you want to go that route. I'd try Ebay, Banggood, or Gearbest. Both the X5HC and HW use the same board...only the camera is different.

 

[chupo_cro]

The same happened to me with X5 when I replaced the motor holders with gears. The gears were very low quality and the flight time with Turnigy nano-tech 750 mAh dropped from 9 minutes to 50 seconds After putting back the old gears the flight time was as before. When the drone was new the flight time with stock 500 mAh battery (which is in fact 625 mAh measured by iMAX B6) was 11 minutes and now after 120+ flights when the gears are old the flight time with the same battery is under 5 minutes.

Worn gears can make a huge difference in current drawn by motors and when the current is too high the voltage drop can be more than 1V so the battery is immediatelly sensed as 'drained'. The same may happen when one of the motors is near its end - such motor gets hot and draws significantly more current than a new one, causing the voltage drop below the threshold.

The gears might not be bad, maybe there is only some dust or something preventing them to run smoothly.