[Kindle Fire Q&A, Help & Troubleshooting] s2p2e:
This worked temporarily, but by the time we got fff and twrp on my device, the battery went completely dead. It would not power the device, and a replacement had to be bought. I do not recommend using this guide unless you have absolutely no other choice.

PLEASE READ EVERYTHING.

This a guide for how to charge your Kindle Fire's battery if you are stuck with the 5 second bootloop and you have tried everything else This is a last resort, and it works by charging the battery DIRECTLY. I recommend reading all instructions before starting.

"tried everything else" meaning:

- Trying to charge for hours using stock Kindle Fire Charger.

- Same with a non-stock 5v charger with at least 1.8 amps (Not counting ipod/ipad chargers, as I've heard they have compatibility issues with the KF. If you have nothing else, try it anyways.)

- Any other method you may have read about.

This WILL void your warranty (which happened a long time ago for most of you, anyways), and I am not to be held responsible for anything that may go wrong when following the instructions posted here. It worked for me! But it is dangerous and I cannot guarantee that this method will work for you.

PROCEED AT YOUR OWN RISK

Now that you understand the risks involved, let's get started.

1. Remove the back from your Kindle. For assistance:

http://www.youtube.com/watch?v=IQ6xxveRJSw

Other various guides are available online. Google search is your friend.

2. Locate the large battery connector (it should have three red wires, a yellow, a blue, a white, and four blacks) and pull it from where it plugs into the board. See 4:35 in the video posted in step one.

3. Now, get the 5v, 1.8+A charger*** you tried (and failed) to charge your kindle with. NOTE: I used a 2.0A charger, which worked fine for me. Normally, higher rates than what's recommended shouldn't be an issue, but I'm not sure that this is still the case as we're charging the battery directly. Cut off the end that plugs into the device (the micro USB end. I recommend leaving enough length on the end so that you may reattach it to the charger cable if you need to). Cut open the case of the cable, being careful to not cut through the inner cables/wires. You need these! There should be one black and one red; these are the only two you need. Strip them. Now, separate one single strand from the rest for both black and red. tape off the remainders using electrical tape. You may also just cut off the extra strands, but you may regret doing so if the flimsy single strand you're using breaks and you have to start all over again with the wire.

4. You should have a 5V, 1.8+A charger with the end cut off, the black and red wires stripped, and only one strand of each exposed. NOW. Make sure your charger is not yet plugged into the wall. Plug the single black strand into the far left black port on the battery's connector (this is when viewing the kindle from the back, right side up. As shown in the the aforementioned video) and the single red strand into the far left red port on the battery connector. There are three reds; make sure you put this in the right one. When the cables are plugged in as securely as they can be and the two strands (black and red) are not touching. Double check this. Now, plug in the charger and wait. I left mine for about thirty minutes, reconnected the battery, and... POWER! Make sure to quickly connect a charger to the kindle fire via the standard charging port to let it finish charging; this just jump starts your battery. If you do not have another cable to charge your kindle with, strip the severed end of the charger and reconnect it where you initially cut it off. Make sure to cover the exposed ends with electrical tape. I do not know if it is safe to leave the device charging directly for an extended period of time. The thirty minutes was enough for me and I did not want to experiment any further than necessary.

I hope you found this helpful! Be careful and may your kindle live on!

*** When charging the battery directly, I'm assuming a 5v charger with less than 1.8A would also work, but I have not tested this. I assume you would just have to leave it charging directly a little longer to get it to a point where the battery can power the device on its own.