[Galaxy Note 10.1 General] Harvolololol:
First time poster. Long time lurker. I'm hoping to add something useful to the community.

I have had my galaxy note 10.1 GT-N801X since launch but as of recently I have been struggling to find a use for it. A couple years ago it started to feel slow and clunky and then I started having problems with the battery. It has then been sitting in a box refusing to boot up until now. I found a couple places that sold replacement batteries online and the price wasn't too bad. Replacing the battery would have been a viable option however I have issues that the device cannot usually be used while charging and it takes a long time to fully charge. Even when the tablet was new I remember that battery live wasn't that great when using it intensively. For me the novelty of the pen had worn off, portability was less of a concern (As I have my phone for that), and the device feels slow and clunky and the screen is not that great by today's standards.

So I decided to fix it as cheaply as possible and design it to be timer for my home gym where it could also play YouTube videos and stream content from Plex web and Netflix if I wanted to. It would be close to an outlet at all times and I would not like to deal with the hassle of dead batteries and not being able to use it while charging. I would not be using the SPEN and I would not be using it for close up viewing tasks. So i decided to remove the old dead battery and hardwire in a plug.

*** CONTINUE AT YOUR OWN RISK *** I AM NOT AN EXPERT AND I AM GENUINELY SURPRISED SOMETHING SO SIMPLE WORKED ***

1. My first step was to open up the tablet and remove the old battery. It wasn't very hard and their are quite a few guides out there already. My only advice is to be careful when removing the connectors. After a couple years some of them have become quite delicate.

2. My next step was to get all of the parts prepared. I had an old 5V USB charging block that can output up to 2A. I had an old USB to micro USB cable that only had 2 wires on the inside. I cut off the micro usb end and stripped the wire ends. Then I cut the 5 wire battery connector off of the old batter and carefully stripped the end of the wires.

Just a note of caution, the original battery says it is 3.7V with a 4.2V max charging voltage. By using a 5V power block you are going to be overpowering the board. I thought I might immediately blow the board or lead to overheating. So far it is not a problem. At this point I have used it for about 12 hours in total and a max of 4 hours a time. But I don't leave it plugged in unattended just in case.

[IMG="The Battery connector from the old battery looks like this. Be carfully as you will only have one shot at this"]https://imgur.com/lQ7mE4U[/IMG]

3. Then I assembled all of the pieces. The salvaged plug from the old battery has 5 wires. The two red are the positive terminal and the 2 black are the negative terminals. I have no idea what the blue is but that is unimportant for the project. Before soldering I tested the outputs from the USB cable. Red was positive. White was negative. The output was 4.8V. I soldered the red wire from the USB cable to the two red wires of the battery cable harness and then soldered the white wire from the usb cable to the two black wires of the harness. I debated whether or not to attach the blue wire to the ground... but in the end I just left it untouched and everything worked out fine. I then covered the solder points with hot glue so they would not short on anything. It was a little bit too tight for electrical tape.

[IMG="Red wire from the USB cable soldered to the 2 red wires of the wiring harness and the White wire soldered to the 2 black wires of the harness"]https://imgur.com/lQ7mE4U[/IMG]

4. I then plugged the wiring harness back into the tablet and attached the wire to the back of the case with some hot glue so it couldn't be accidentally ripped out. I didn't bother putting the cover on the back of the tablet. I just put on the case and cut a small section out so the cable could pass freely through the side. I then powered it up and installed the newest version of lineageOS and my apps.

Finished project:

[IMG="The back of the tablet. With the battery removed and the wire attached."]https://imgur.com/A8MY1be[/IMG]

[IMG="I had an existing battery pack with a 5V 2A output that will also power the device if at some point I want it to be portable"]https://imgur.com/4VUONyr[/IMG]

[IMG="The finished project. My gym timer"]https://imgur.com/uvNxwUI[/IMG]

Update:

Here is the link to my imgur album imgur.com/a/IAl7n