The Perfect Lipo discharge tool? URUAV Lipo Discharger how to Hack DIY

The Perfect Lipo discharge tool? URUAV Lipo Discharger how to Hack DIY

First of all yes I know the only right way to discharge a lipo is to fly it.  

But sometimes it can happen that due to bad weather or stress at work and or with the family and so on, you have full lipos and now you have to find a way to unload, and I finally found a solution that seems good to me and that for less than 25dollars!
This will be an ongoing tutorial, so this is only the first try and I will update it as often as possible.

Video of the tool and how the mod is built and works.

1. Description of the Tool URUAV Lipo Killer Discharger
2. How to Hack/Improve the Discharge time – Description
3. What to you need for the mod
3a. How to Build
4. Danger and Saefty
5. How to Discharge a Lipo Battery for disposal

1. Description of the Tool URUAV Lipo Killer Discharger

So let’s start this little tool the URUAVUR4 Lipo Killer Discharger

You can find it on Banggod link for about $6.80 in flash deal for the next few days.

The tool has two functions, the XT60 on the right is a 0 Volt Discharger this is useful for half-dead lipos after a crash and you want to discharge this 0 before you can put it in the trash. (it takes about 24 hours)

The balance plug on the other side is the 4.0 to 3.0 Volt Balance Discharger 1-6S.
Yes, you read correctly that it balances the cells and this is one of the great advantages compared to other dischargers on the market.
Another advantage is that once the URUAVUR Lipo Discharger reaches the final discharge voltage, it automatically shuts down without fan noise.

Here a short description from Banggood

Usage Instruction:
0V Discharger– Plug your battery’s XT60 Connector in the yellow connector ( on the right side of board)- Then 0V LED will keep lighting untill finishing dischager- 0V LED Light goes off, which points at battery dischager to 0V.- Discharging to 0V need 24 hours above4.0V-3.0V Discharger Balancer– Plug your battery’s balance pin head in the Pin connector ( On the left side of boaed )  

Notice: The battery’s black cable points at “ G“ ( The word showed on the board)
DONT plug in opposite side.- Then this lipo killer will test how many cells of your battery and counterpart LED will light on.  1S-6S Discharge LED will keep light. ( The lighting LED Number depends on your battery’s Cell)- Press “ Set „ button to set the voltage you want to discharge. ( 3/ 3.2/ 3.4/ 3.6/ 3.8/ 4V Optional)  Notice: The voltage you set must lower than your battery’s present voltage- 1S-6S Discharge LED goes off while finishing discharging- Discharging from 4.2V to 3.8V need about 5 hours ( take example as 1300mAh Lipo Battery)
As you can see above from a full 1300mha Lipo to 3,8 Storage it took around 5 hours (this is really long)
In my own tests, it took longer and depends on the mAh from Lipo more mAh more time.
But the best part is that the Tool discharge full automatic to the set Volt and then turn off and this balanced on all leads from 1 to 6S and that is really great.

2. How to Hack/Improve the Discharge time – Description

According to the description it takes about 5 hours and more for
larger lipos and that’s not really fast, safe and without noise, but not
fast, so I was looking for a solution to shorten the discharge time.
That’s why I looked at how this tool works, I saw that the resistors on
the bottom of the tool are separated for all 6 wires, always two of
them. From my other discharge projects in the past I know that I can use
lamps (G4 sockets and lamps) to improve the speed, but this time the
discharge channels are switched on and off with electronics, so we have
to be careful that the lamps don’t overload the electronics, it worked
with up to 10W lamps without any problems in my previous tests. 

Video Link

With 10 Watt G4 lamps I have discharged a 1550mhA Lipo from 100% to
below 20% (3.6Volt) in about 2 hours (you can see this in the video)
with 5 Watt lamps, it took about 3 hours (also in the video). So we can
say for the normal 3.8v memory voltage that it takes about an hour and a
half or less with a 1550mhA Lipo and that’s a nice speed, isn’t it?

3. What to you need for the mod

one (or more) URUAV UR4 Lipo Killer Discharger Bangood Link

6x G4 Lamps 5 to 10 Watt 12 V (10x Lamps in Package)

6x G4 Keramik Sockets with leads (5x Socket in the Package)

Optional my Designed 3D Printed frame thingverse Link

With the Packages from Amazon, you can build one 6S and one 4S Discharger or two 4S and one 2S and so on.

3a. How to Build

To build it is very easy and is shown in the Video around 4:38.
As described above, there are always two resistors in a row. (left to right)

for one cell of your battery, the lamps leads will soldiers on both sides of the two resistors.

Then install the lamps and finish.

For each cell of your battery, the lamp leads are soldered to one end of the resistors.

Then plug in the lamps and you’re done.

With the 3D printing it looks like this, but the design is not finally a work in progress any more better ideas are welcome!

4. Danger and Saefty

First of all, take care of your lipos and always check them for
damage, always keep an eye on the lipos and this tool and never leave
them alone in the room.


Use a smoke detector!

5. How to Discharge a Lipo Battery for disposal

There are other ways but at the moment this is one of the easiest ways I found to Discharge a lipo to Disposal Voltage.

Most of the current charger can Discharge a lipo but mostyl only with a view watt/h and it takes forever to finish

There is also a Discharger from ISDT (I have on here) this was also
great but I realy get anoyed by the small fan the noise is realy loud.

6. Updates and whats next

I tested this tool now for over 3 Weeks with around 45 lipos from
2S to 6S what I Looking now is can it handle safe 15 or 20Watt lamps
(this will boost the time) but what also has to considert the Balance
leads from the lipos are only good for a view amps so more testing has
to be done.

What I found is when lamps has higher Watts the drifft of the
voltage regulatet is getting bigger maybe I can mod the hardware to make
that less.

I also working on an Datasheet where I but in my Discharge times
but this is in earlier not finished status so please give me time


Thanks for reading hope you like this tool and the mod and you can get a use out of that.



How to Flash Betaflight & Dshot Step by Step Setup & Install

How to Flash Betaflight & Dshot Step by Step Setup & Install

DSHOT the new star on the BLHeli_s ESC Protokoll´s

This is my first howto so please forgive me some mistakes and typos i will frequently update the post when something is changing.
(last update 13.03.2017 changelog on the end)

When you think hmm DSHOT can i eat that or what is that than give Oscars Overview a read he did a really good comparison between the different ESC Protokolls!
Oscars ESC Protocols Overview

For your own testing and building, you need

an support F3 or F4 flight controller (FC)
and supported Blheli_S ESC  more of that in the hardware section

In my Example i use a CC3D Revo F4 Clone from Banggood referral Link
and DYS XS30A ESC also from Banggood referral link

I made a full video step by step of the steps below!

1. Lets start
2. flash FC & ESC
2.a after flashing FC Firmware
2.b ESC flashing
3. Setting min Throttle with Dshot
4. Warning!
5. All needed Software Links!
6. Hardware i have testet so far with dshot
7. Flight Video´s

1. Lets start

So first of all give the Betaflight DSHOT WIKI a read! you find it here Betaflight DShot Wiki


If you confirmed that you have one of the almost supported FC and ESC you can go to the next steps.

When your ESC is listed with „Cap removed“ then note that they for now only work with Cap removed when you want to use DSHOT 600 you must remove it but take care removing the cap is not so easy because they are really tiny!!

Some ESC work with dshot 150 and 300 with cap on Kiss ESC work in all modes!, go and check the wiki and the RCgroup Links to find out if your ESC is working and in what modes!

2. Flash the FC and ESC

  1. Start the Betaflight Configurator Chrome App (for some boards you need the Raceflight Configurator to flash)
  2. go to the flash tab and search for the right board in my example is use the Revo board!
  3. In the next tap under the board selection select the latest aviable Betaflight build (for now it is 3.1.7)
  4. press the „load it online button“
  5. On the most boards today their is an Boot button press that button and hold it down, next connect the FC with USB (normaly the betaflight configurator shows an DFU mode on top Right Corner), now you can stop holding down the boot button
  6. and at least press the flash button in the Betaflight configurator.
  7. Wait for the program finishing this step it could take a while!

2.a after flashing FC Firmware

A copy from wiki but this is an important step!
An quick way to determine IF the hex flashed supports Dshot:
Connect to Betaflight and in the Configurator Tab klick on the on the Protocoll drop down (on right up corner)

2.b ESC Flashing
Only go to the next step when there is DSHOT listed in the drop down

  1. Close the connection from Betaflight configurator
  2. open chrome and use the BLHeli – Configurator chrome app BLHeli configurator Chrome App
    you can also use the normal BLheli Suite! BLHeli Suite downloadPower up your ESC with a lipo (NO PROPS ON THE MOTORS!!!!!!!!!!!) and connect to it with the BLheli app or the Programm!
  3. Now take the flash step like in the picture version take 16.6 (or newer) now with Dshot (the Dshot firmware is for all BLHeli_S ESC listet) in the configurator you have only switch to the version and press flash!
  4. After you flashed all 4 ESC make sure you set for all 4 ESC the min throttle to 1000 and max to 2000 this is IMPORTANT!
    on some ESC mid throttle is not 1500 make sure the values match this! since 16.43 Blheli this should be ignored but safety first!

2.c Last steps

  1. So now we can close the app and go back in Betaflight configurator in the config tap we set to DSHOT 150/300 or 600
  2. in my example i can take 600 with my DYS XS30A „Cap removed“!
  3. So for now you are ready to do a Bench test!
  4. So before you go out and flight one major step I copy that from Betaflight WIKI you should allready know it

3. setting Min Throttle with Dshot

Post by Cheredanine on setting up IDLE in ßF 3.1.2 and up:

Ok first Point – dshot does not use min and max throttle, you don’t need to do that.
Second point – when not using min and max throttle you should calibrate from bf, not manually set in blheli.
Could someone please explain if I need to type the „digital_idle_offset“ command?
So let’s deal with your question.
To check what value digital idle should be set to, connect to configurator, go to the motor tab, take your props off. Click the little check box half way down the page that says you have taken your props off, you know what you are doing, you take full responsibility for your actions and you consider fingers pointless appendages anyway.

Then plug in the LiPo to the quad (USE a Current Limiter Always). Click on the master slider and use the up arrow on the keyboard to increase the master slider one point at a time until you reach a point where all 4 motors have just started to spin, I don’t mean twitch, stutter or start stop, I mean the lowest value where they are spinning, it is probably about 1010, don’t worry if it isn’t, but I am going to use that number as an example.

You can now take the master slider back to zero and unplug the LiPo.

Take the number (for example purposes 1010) and add thirty points to it (so in the example we are now at 1040).
Not we need work out what percentage of the throttle range this is, I don’t know your math skills so sorry if this is a little hand to mouth.
Subtract 1000 from it, then divide by 10

So in the example:

Go to the cli tab in configurator
Click in the box at the bottom and type:

set digital_idle_percent = 4

(Replace 4 with whatever digital idle you arrived at in the calculation) Hit return, you will see the command processed in the back bit above, Then click in the box again and type


Hit return and done

in my tests the standart value from configurator works perfect!

4. Warning!
Have fun but play save! flash and miss configuration can harm you and your hardware!
So be carefull!

5. All needet Software Links!
Betaflight DShot Wiki
Betaflight 3.1.7 (link point allways to the new release)
Betaflight Configurator Chrome App make sure you have installed the latest version!
Raceflight Configurator Chrome App
BLHeli configurator Chrome App
BLHeliSuite download latest!

6. Hardware i have tested so far with dshot

In this section i post all the hardware i have tested so far and beyond that, i repost this to an rc group and make sure that the things come up to the wiki.

For now  I have 6 Dshot test quads all around 2300-2400KV Motors (ZMX Fusion X25, Corpa Champion, Emax RS2205 RS, RCX 2205 V2 2400KV, ) and more on all quads i fly different ESC and Flight Controllers.

I will update this section more often the next days and make some setup video´s
So stay tuned!

But you can also check the Betaflight DShot Wiki for more info’s and hardware setups i can not have all the hardware here because my bank account says no Cry  i spent a lot of money this days for figure out the best Dshot ready setup so when you have some info they can help let me know!

FC i have tested and they work
  • CC3D Revo F4 Banggood referral Link
    Work with Dshot 600 and 8K/8K loop times with less then 5% CPU Load (Air mode and Telemetry on) only one thing doesn’t work for now the LED Stripe maybe in the final 3.1.0 Betaflight it may works again soon more videos about that and more!“betaflight_3.1.7_REVO“
  • Lux 32-Bit F3 (Lux race v1 clone) Banggood referral Link
    Work with Dshot 600 and 8K/4K Loop times with around 35-38% CPU Load with 8/8K the CPU load is 100% to havey (BF 3.1.0 Alpha Build 731 from 05.12.2016)
  • F3 V4 HCL Tech Banggood referral Link works great with „betaflight_3.1.0_SPRACINGF3“ RC12
    Loop time 4k/2K (soon more test with higher Loop times)
  • TBS FPV Stack with Coloibri Race V2 with „betaflight_3.1.7_COLIBRI_RACE“ (don´t use 3.1.6)
    Did Some testing it work with 8k/2K on around 19% CPU Load with the latest BF build. You can also Run 8/8k when you disable the gyro (no need for acro racing)
    Sp Racing F3 with „betaflight_3.1.7_SPRACINGF3“
  • Looptime 8/4k on the latest Betaflight build
  • Omibus F4 clone from Banggood works on 8/8k mode wit betaflight 3.1.7 on around 4-5% cpu load perfekt! also tested Smart Audio Port with unify pro and OSD soon i will upload a video about that! link to smar audio wiki page Smart Audio Link
FC i will test in the next days
  • Betaflight FC
ESC I Have tested and Work

  • TMotor 30A (work perfect on dshot600) one of the best performing so far for me!
 ESC i will test in the next days
  • Kiss24A Race

Iwill add more stuff the next weeks so stay tuned

7. Flight Video


TBS Crossfire 500mw to 2W with a Switch | Taranis Battery Mod

TBS Crossfire 500mw to 2W with a Switch | Taranis Battery Mod

This time I show you a mod of my Taranis and #TBSCrossfire full module how to switch the power with one button from max 500mw to 2W without the need of an external battery, I use this now for over a year and I’m pretty happy with it maybe some of you can use this too.


This is the First Video in a row of upcoming How to Videos about #Longrange flying and the parts and stuff around.

You need:
a switch like that for the Fatshark mods
XT30 connectors and some wire
and this 3D Print
Bigger internal Battery like a 2500 or 2800mha

The 3D print in my video was done with my new mk3 at full speed so its more a prototype, print it slower for better quality! The TBS Crossfire module is normally only designed for 500mw via the internal connector of the taranis XD9, but with an external lippo it can be amplified up to 2 Watt.

To boost this with the button from 500mw to 2 watt you have to set the TBS Crossfire module dynmaic Power to on.

Normally the 500mw is enough for the comfortable midrange surfing more than most people already have enough with 100, but if you want to fly really long range fpv and test your limits then more power is just the right thing.

Flying with our long range fpv quadcopters is a lot of fun and this mod helps to make life a little easy without the annoying separate battery plug it in etc. so try it out and have fun with it if you like you can buy me a beer 🙂 It should be said that in many countries there is a limitation of broadcasting performance and there are legal exceptions such as amateur radio and other tests, etc. Please inform yourselves just before you start.

the approach with my mod is that this can be switched on and off at any time.

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