URUAV LiPo Killer

URUAV LiPo Killer is a small device that is designed to do 2 things:

  1. kill a LiPo. When the battery is close to its death and should be disposed of, you can not just throw it away. It still has some electric charge inside and can catch fire when not handled properly. Discharge with a low current will drain the battery to 0 in a safe way
  2. Discharge it to the desired level. For example for storage. You plug the balancing lead, select cutoff voltage with a button and leave it for a night. Built-in microcontroller (STM32F103, the same that is in Naze32 or CC3D) will measure voltages and stop the discharge when voltage will drop to the level you want

DIY 4S battery pack from 18650 Li-Ion for RC FPV drone

‘ve made me an endurance Li-Ion battery pack for my 7 inch endurance quadcopter. With good quality Sony 18650 VTC6 it is possible to get 20A constant current which is enough for an airplane or endurance quadcopter. Works just fine and with reasoable speed of 40-50 km/h I’m getting more than 15 minutes of real flight. Not hover. Flight. And at the end, it still has some juice inside. Not bad, not bad at all.

Fix an old powerbank with 18650 Li-Ion batteries

Let’s get our hand dirty and fix an old power bank. I got this thing a few years ago but recently it died. Li-Ion 18650 cells inside just died and now it even can not do a full charge of a smartphone.
What we will do over here:

  • get this thing apart
  • solder together 3 18650 batteries I got for cheap from disassembled power tools battery packs
  • I will be coughing after inhaling too much of soldering acid fumes
  • have a nice talk about a zombie apocalypse, nuclear holocaust, communism and Kapton tape
  • get things done!

How to solder 18650 Li-Ion batteries

All 18650 Li-Ion batteries are hard to solder. Well, not only 18650 but all nickel plated metal elements can be very hard to solder. But only if you do not have the proper tools. In this case, proper flux: soldering acid. Forget about sanding, scratching and other voodoo. Just watch the video, it will clearly show what I have in mind!

No more sanding or scratching of 18650 Li-Ion connectors. A drop of soldering acid sill all that you need!

Getting started with 18650 Li-Ion batteries

18650 Lithium-Ion batteries are the workhorse of modern consumer (and not only consumer) technology. If you have anything that is battery operated and there is a “Li-Ion” mark anywhere on it, probably it is powered by 18650 Li-Ion battery. Laptop batteries, cordless drills, cordless tools, e-cigarettes. All of them (probably) have 18650 cells inside.

In this video, I will just go with the basics of 18650 cells. Dimensions, protected / not protected difference, weight and so on. Expect more in the future!

Tutorial: replace battery in RunCam HD

My RunCam HD died after 5 months in a drawer. Reason: battery destroyed. It had enough energy for approx. 2 seconds of operation. So I had a choice: buy original battery from RunCam for $9.99 plus shipment, or fix it DIY style. I’ve choces the second option.

Luckily for us, RunCam used generic 803035 LiPo 1S, 3,7V battery that can be purchased in specialized stores. I’ve paid around $6 for mine, but if you look hard enough, you should find something even cheaper. Also, luckily (or not) there is a battery plug: 2 pin JST 1.25mm.

Runcam HD inside

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How to connect APM Power Meter to Cleanflight and INAV

This topic was eluding me for some time now. It’s time fix the problem and finally present a short tutorial how to connect 90A APM Power Meter for flight controller boards like Naza32, SP Racing F3 or any other running Cleanflight / Betaflight / INAV software and equipped with Current Meter ADC input.

I will not show where to connect APM Power Meter to flight controller, since this differs from board to board. Some boards have dedicated pins, on some boards PWM input pins are used for Current Meter ADC. You have to refer FC documentation and / or flight controller software documentation.

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How to dispose / utilize LiPo batteries

LiPo batteries that run RC hobby are potentially dangerous devices. When not handled properly they can ignite or even explode. And they do not live forever. Even the best battery, no matter how taken care off, loses capacity, swells and has to be disposed. When we combine both facts we face a problem: how to dispose old LiPo batteries if they can catch fire? It’s extremely hard to find a place that accepts them for utilization. Throwing out with garbage is not a good idea. Disposing with popular alkaline batteries might sound as a good idea, but it is not either. So, how to utilize old LiPos? This is quite easy…

  1. Build a LiPo discharge device using 24V halogen light bulb. No high-tech here, just a way to connect light bulb to a battery. 12W halogen is generally a good option for both 3S and 4S LiPos
  2. Put a battery inside ceramic pot with some sand (not flammable if thing go very very wrong for any reason), connect “discharge device” and let it do its job. Light bulb limits discharge current, so LiPo should discharge nicely without extra swelling or overheating Magical LiPo tree Read More