DIY 12 Volt Lipo Battery Discharger

Written by: Tony Korologos | Date: Saturday, May 28th, 2022
Categories: Build LogDrones For GoodRandom

I have a pile of lipo batteries that have gone bad and haven’t been able to dispose of them properly. Most have a bad cell or two so they’re dangerous to throw away or destroy. I needed a solution to discharge the lipos completely and found a cool article by Oscar Liang for a do-it-yourself discharger. I followed his spec, except I only made a 12 volt version instead of his version with a jumper to switch from 12 to 24 volts.  I have a cool little discharger (3rd image) for bringing batteries to storage voltage so any lipos I have that are over 12 volts I set them to 3s and let the discharger bring them down to the 12 volt range.  Then I slap the battery on my discharger and it will kill them quite fast.  After a few hours, or even overnight, the voltage on even a 6 cell is only around .01-.04 volts.  At that point I can just short the positive and negative wires together and finish it off.  Then I clip the plugs off and save them for other uses and the batteries are ready to be disposed of.

Being the geek that I am, I designed and 3D printed a little case to make it nice.  Here’s the final product.

And here it is in action.  The lights start out quite bright and hot if the battery is up at 12 volts, but after a few seconds they dim as in the photo below.

And below is the discharger which I bought at Pyrodrone for around 6 bucks. It has a little button to switch the values to 2s, 3s, 4s, 5s, 6s.  The battery I’m discharging is a 22 volt 6S which I’ve got down to 15.2 volts.


Law Enforcement’s Drone Education

Written by: Tony Korologos | Date: Tuesday, February 2nd, 2021
Categories: Multirotor AircraftRandom

I tried my 2nd Skydio 2 test flight today at a local bike park. It was quite muddy around so when I saw the park police officer there I thought I’d check in with him so make sure I was about to ride trails that were okay to ride. I had already launched my Skydio 2 and it was hovering about 30 feet front-right of me.

The cop was annoyed by the drone and asked me to move down 50 yards to talk. He didn’t realize the drone was tracking me. So after we moved I explained to him I was in control of the drone. That’s when the entertaining, but sad conversation took place.

Me: “I’m controlling that drone.”
Officer: “You can’t fly that thing under 400 feet.”
Me: “No. Drones can’t be flown OVER 400 feet.” (see pic where I’m motioning with my hand, 400 feet)
Officer: “You can’t fly that thing under 400 feet AGL.”
Me: “No. Above 400 feet. This drone won’t even fly above 400 feet. It’s programmed not to.”
Officer: “You can’t fly that thing over people.”
Me: “I’m not flying over people.”
Officer: “You can’t fly that thing over houses.”
Me: (He’s wrong, but I didn’t tell him) “I’m not flying over houses.”
Officer: “Do you have a license for that?”
Me: “Yes.”
Officer: “What’s your question?”
Me: “I just want to know what trails are okay to ride here, given the muddy conditions.”

So this officer was damn sure you can’t fly a drone under 400 feet. I didn’t ask him, but how would one launch the drone, since you know, the ground is under 400 feet AGL (above ground level). I suppose one could fly a helicopter up to 400 feet then hand launch it from there. It sounds to me like the officer had one briefing on drones and all he could remember was 400 feet.


Faa Sample test questions to study

Written by: Tony Korologos | Date: Friday, August 21st, 2020
Categories: Random

1. The “yellow demarcation bar” marking indicates

    A yellow demarcation bar is a yellow pavement marking of a single line that indicates a runway having a displaced threshold which is preceded by a blast pad, stopway or taxiway.
Answer B is incorrect because a hold line is a yellow pavement marking from taxiways to runways that consists of two solid bars and two broken bars. Answer C is incorrect because the available landing area of the runway begins after the displaced threshold, not after the demarcation bar.

2. (Refer to Figure 23.) The flag symbols at Statesboro Bulloch County Airport, Claxton-Evans County Airport, and Ridgeland Airport are

3. According to 14 CFR part 107, the responsibility to inspect the small UAS to ensure it is in a safe operating condition rests with the

4. (Refer to Figure 21, area 1.) After receiving authorization from ATC to operate a small UA near Minot International airport (MOT) while the control tower is operational, which radio communication frequency could be used to monitor manned aircraft and ATC communications?

5. The CARE attention scan can be used

6. You are a remote pilot for a co-op energy service provider. You are to use your UA to inspect power lines in the remote area 15 hours away from your home office. After the drive, fatigue impacts your abilities to complete your assignment on time. Fatigue can be recognized

7. Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?

8. (Refer to Figure 26, area 5.) The airspace overlying and within 5 miles of Barnes County Airport is

9. Airspace at an airport with a part-time control tower is classified as Class D airspace only

10. Safety is an important element for a remote pilot to consider prior to operating an unmanned aircraft system. To prevent the final “link” in the accident chain, a remote pilot must consider which methodology?

11. What is the antidote when a pilot has a hazardous attitude, such as “Macho”?

12. Uncontrolled airspace is

13. Which weather conditions should be expected beneath a low-level temperature inversion layer when the relative humidity is high?

14. A pilot experiencing the effects of hyperventilation should be able to restore the proper carbon dioxide level in the body by

15. When turning onto a taxiway from another taxiway, the “taxiway directional sign” indicates

16. When operating an unmanned airplane, the remote pilot should consider that the load factor on the wings may be increased any time

17. In accordance with 14 CFR part 107, except when within a 400′ radius of a structure, at what maximum altitude can you operate sUAS?

18. (Refer to Figure 25, area 3.) If Dallas Executive (RDB) Tower is not in operation, which frequency should be used as a Common Traffic Advisory Frequency (CTAF) to monitor airport traffic?

19. According to 14 CFR part 48, when must a person register a small UA with the Federal Aviation Administration?

20. The numbers 9 and 27 on a runway indicate that the runway is oriented approximately

21. What are characteristics of a moist, unstable air mass?

22. (Refer to Figure 18.) Of what value is the Weather Depiction Chart to the pilot?

23. The vertical limit of Class C airspace above the primary airport is normally

24. (Refer to Figure 23, area 3.) The top of the group obstruction approximately 11 nautical miles from the Savannah VORTAC on the 007° radial is

25. An almond or lens-shaped cloud which appears stationary, but which may contain winds of 50 knots or more, is referred to as

26. Two-way radio communication must be established with the Air Traffic Control facility having jurisdiction over the area prior to entering which class airspace?

27. (Refer to Figure 20, area 1.) The NALF Fentress (NFE) Airport is in what type of airspace?

28. (Refer to Figure 64.) Which marking indicates a vehicle lane?

29. In which environment is aircraft structural ice most likely to have the highest accumulation rate?

30. Which is true concerning the blue and magenta colors used to depict airports on Sectional Aeronautical Charts?

31. (Refer to Figure 15.) What is the valid period for the TAF for KMEM?

32. What are characteristics of unstable air?

33. Crests of standing mountain waves may be marked by stationary, lens-shaped clouds known as

34. Which factor would tend to increase the density altitude at a given airport?

35. In weight and balance calculations, arm is

36. Unmanned aircraft means an aircraft operated:

37. The amount of excess load that can be imposed on the wing of an airplane depends upon the

38. The effective use of all available resources—human, hardware, and information—prior to and during flight to ensure the successful outcome of the operation is called:

39. At what bank angle for a turn does the additional force on the wings become significant?

40. Under what condition would a small UA not have to be registered before it is operated in the United States?

41. According to 14 CFR part 107, how may a remote pilot operate an unmanned aircraft in class C airspace?

42. To avoid a near midair collision (NMAC) with a manned airplane, you estimate that your small UA climbed to an altitude greater than 6400 feet AGL. To whom must you submit a written report of the deviation?

43. Every physical process of weather is accompanied by, or is the result of, a

44. One weather phenomenon which will always occur when flying across a front is a change in the

45. (Refer to Figure 20 area 4.) What hazards to aircraft may exist in restricted areas such as R-5302B?

46. (Refer to Figure 65.) The red symbol at sign D would most likely be found

47. The four forces acting on an airplane in flight are

48. A resource you can use to find out detailed information about the effects of alcohol and legal and illegal drugs is

49. Scheduled maintenance should be performed in accordance with the:

50. What effect does high density altitude, as compared to low density altitude, have on propeller efficiency and why?

51. Basic radar service in the terminal radar program is best described as

52. (Refer to Figure 22, area 3.) Determine the approximate latitude and longitude of Shoshone County Airport.

53. If a certificated pilot changes permanent mailing address and fails to notify the FAA Airmen Certification Branch of the new address, the pilot is entitled to exercise the privileges of the pilot certificate for a period of only

54. A small UA causes an accident and your crew member loses consciousness. When do you report the accident?

55. Which technique should a remote pilot use to scan for traffic? A remote pilot should

56. (Refer to Figure 26, area 2.) What is the recommended communication procedure when inbound to land at Cooperstown Airport?

57. Which of the following types of operations are excluded from the requirements in part 107?

58. (Refer to Figure 20, area 5.) How would a remote PIC “CHECK NOTAMS” as noted in the CAUTION box regarding the unmarked balloon?

59. What effect does haze have on the ability to see traffic or terrain features during flight?

60. Under what condition should the operator of a small UA establish scheduled maintenance protocol?


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