Tag Archives: hacks

Charge Bauer 20v Lithium Packs Using a Balance Charger

This all started the other morning when I realized I had left my Bauer battery pack and charger outside in the rain. Long story short you can use the plug from a broken charger to make an adapter to charge your battery packs with a RC Vehicle Balance Charger.

Bauer 20v + TBS Charger
Bauer 20v Pack Connected to Balance Charger

The Story

After sitting, plugged in, in the rain, overnight, there was a large amount of blue material on the battery and charger connections.

Pushing the button on the battery showed full charge, so I cleaned off the connections and tried it in my drill. No dice. I dissembled the battery pack by removing the four torx screws on the bottom. There was corrosion on the inside of the connector but everything else looked OK. I cleaned off the connectors from the inside and reassembled the battery.  JOY! The battery is working again.

Things were not so good for the charger. Under the charging board there was a huge black spot where a bank of resistors had fried.

Magic Smoke Stain

I was thinking about repairing it when I noticed that the plug part inside the charger was a self contained unit. Not only that, the connection plug for the sense port was the same as the plugs on the batteries for LiPo  RC batteries (eg Drone Batteries).

The pin-out on the above mentioned plug is not the same as a standard RC LiPo battery, but all the necessary components (and then some) are. If you are looking at the balance plug (on a Drone Battery for example) with the bumps facing down, the leftmost wire is ground and the next wire to the right is the voltage of one cell. The third wire is the voltage of two cells, the fourth wire is the voltage of three cells and so on depending on how many cells you have.

The Hack

In a nutshell we need to make the Bauer battery pin-out match a stander RC Lipo Battery. The finished adapter will look something like this:

Bauer Adapter Dongle
Bauer Adapter Dongle

You will need security torx bits (with holes in the middle) to remove the bottom plate from the charger. Then just unscrew all the Philips screws until you have just the battery plug unit. Unplug the 6 wire plug from the board and cut the red and black wires as close to the board as possible.

Using a small screwdriver to press down the tabs, remove the pins from the 6 pin plug (they need to be rearranged).  The small yellow and red wires (that you just pulled from the plug) are for the battery’s internal temperature sensor, we don’t need to monitor this sensor so we can use these wires to finish our plug. De-solder the small yellow wire and solder it with the main negative (big black wire). De-solder the small red wire and solder to the main positive (big red wire).

Move small red wire to big red wire post. Move yellow wire to big black wire post.

Solder a battery connector (salvaged from old battery pack) to the main positive and negative (big wires). Finally reinsert the pins into the plug as pictured:

Bumps Up: Red, Grey, Black, White, Blue, Yellow

The adapter is finished and just needs to be tested. Plug the adapter into your Bauer battery pack. Using a volt meter your battery plug should show about 20v. With the bumps facing down your 6 pin plug should test as follows (voltages are approximate and will vary depending on the level of charge):

  1. Yellow: (-V)
  2.  Blue: (+3.7)
  3. White: (+7.4)
  4. Black: (+11)
  5. Grey: (+14.7)
  6. Red: (+18.4)

Using the adapter you can now connect and charge your Bauer tool packs. In the program mode set your battery type to 3.7V (Lithium Poly or LiPo). Set the amperage to match the AH listed on the side of the battery pack. The charger will auto-detect the number of cells (5) and  after doing a quick balance on the cells will charge the pack until full.

LiPo Charge, Auto
Charging in full swing
Individual Cell Voltages and Balance Charging

In summary, this hack is very simple and could be considered an upgrade to the charger from HFT. Having the info display showing the voltage of each cell and balance charge mode are both great. There is also a fast charge that I haven’t tried, but this already charges my batteries quicker and more completely than the Bauer charger.

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Amazon Kindle Fire 5.3.1 Hacked – Rooted and new Rom

I just purchased a Amazon 5th gen kindle fire to use as a ground station for my drones. The device supports OTG and has the power needed to run the 3dr usb telemetry device.

Out of the box the fire is kind of useless for anything but an e-reader amazon buying tool.  Rooting and a ROM upgrade solves this! It is fairly simple, however the process is time consuming with lots of waiting (have something else to do like a book or a movie while you’re waiting on certain processes).

Step 1: Make sure you have 5.3.1.0 fire OS installed on device
Go to Settings -> Device Options -> Software Updates to check the version. My device shipped with 5.3.1.0 so I did not need to load a different firmware. Your mileage may vary.

If version is less than 5.3.1.0 follow This Guide instead.

If version is greater than 5.3.1.0 follow these instructions to install the 5.3.1 firmware. download from here

DO NOT attempt to downgrade a > 5.3.1.0 device below 5.3.1.0!!! This it will BRICK your fire.

Once version is 5.3.1.0 go to step 2

Step 2: Reset to factory settings
Go to Settings -> Factory Reset and perform a factory reset. This will reboot the device.

When device boots skip all set up and do not connect to WiFi yet (this will slow down any unwanted update process).

Step 3: Enable Developer Mode
Go to Settings -> Device Options and tap the build number seven times to enable dev mode.
Go to Settings -> Device Options -> Developer and turn on USB debugging and ADB.

Step 4: Download needed files
Download the latest SuperTool from RootJunky and extract somewhere you will remember.

Download the latest Nexus ROM for Fire Tablet but DO NOT extract it.

Step 5: Run SuperTool
From a command line navigate to the SuperTool folder and run the appropriate file. In Linux the command is
$ ./3-Amazon-Fire-5th-gen-linux-mac.sh
You will see a screen like this:

Press 2 and Enter to root device. First it will install KingRoot to your device which you will then have to run from your device when directed to do so. KingRoot will ask you to connect to WiFi.

You will likely have to run KingRoot repeatedly before it will work. Time to grab a book or a movie as this part takes time. Each time you run KingRoot it will reboot your device a few times and show progress on the screen. Each attempt takes about 10-15 minutes or more. After the first attempt I unplugged my device from the computer and had to run KingRoot a total of 4 times before it worked. Just keep trying.

Once root is gained plug your Fire back into the computer (you may need to cycle the ADB setting on your device for it to be recognized) and continue the SuperTool process following all instructions there. This will install SuperSu which will need interaction from you on the device. Follow the setup procedure according to the instructions in SuperTool.

Once this process is done run “Block OTA updates” to prevent accidentally losing root access.

Step 6: Install Rom via FlashFire
While still in SuperTool install FlashFire (option 6).

From your computer copy the zipped ROM file downloaded in Step 4 over to the INTERNAL storage of your Fire device.

On your device run FlashFire and follow these steps exactly, otherwise you risk the installation having problems:

Select the red plus (+) button to expand a selection of options, choosing Wipe.
Select System data, 3rd party apps, and Dalvik cache if they are not already checked.
Click the red plus (+) button again and choose Flash ZIP/OTA.
Search for the Nexus ROM that you’ve copied over and choose it.
Automount and Mount /system read/write need to be unchecked.
Drag Wipe to the top of the queue.

Hit the flash button to start the process.

This will take a few minutes and the screen might go blank for a while. It will eventually boot into the new ROM.

Step 7: Enjoy!
With new ROM installed be sure to update Google first. After it updates clear google app and framework cache and reboot.

Install apps. You will need EVERYTHING as this is a very vanilla ROM.

OTG works great with APM/Tower or DroidPlanner software.

Much faster, full play store support and NO ADS! Yay!