Clickbait title but true.
I just found my Quest Pro being COMPLETELY DEAD even though I almost had it charged every day and I used it very lightly. No LED lights, no "hold these buttons to boot or reset", nothing worked.
Leaving it on the stand overnight, as well as trying to charge with a phone charger etc, nothing worked because it was refusing to charge.
I ended up opening the battery compartment and measuring voltage (2.71v) which is deeply discharged but not terrible.
So I ordered a 3$ TP4056 charger and directly charged it for 10 minutes and it went up to 3.5v.
I then connected the battery to the headset's own wiring and let it charge through its normal charger and guess what, it's charging!
Just FYI, this is an out of warranty device and I went through Meta twice and unfortunately the support were suggesting holding the power + volume down, as well as wanting me to boot the device in boot mode and Adb using a PC, consistently ignoring the fact that it's dead.
I even offered to pay for repairs by Meta and they said they won't do it for out of warranty devices. I almost lost a 1500$ product for a simple discharge issue.
I attached some pictures to better show the wiring.
⚠️ Please, do NOT attempt this if you're not experienced with this type of modification, power circuitry or electronics. It might be worth going to a console repair shop and asking them to do it for you or replace the batteries, before wanting to spend on a new VR headset.
⚠️ Also, lithium batteries 🪫 are notoriously dangerous if they are poked. Be very careful.
Some details:
I soldered two wires to the charger TP4056 then checked with a voltmeter to verify the polarity.
I then connected the charger to a USB-C power Bank. The charger showed a blue light 🔵. TP4056 has a shutdown system that if there's no power consumption it may turn itself off ⚪. So make sure before that happens that you do this next step.
Touch the PACKN pins with the negative ➖ wire coming out of the TP4056, and the PACKP pins with the positive ➕ wire. In other words, positive to positive, and negative to negative. Do not trust the wire colors, check with a volt meter to be sure.
You should now see TP4056 led turn red 🔴, that means it's charging. If you see blue 🔵, you have not made contact ❌. Try again from step 2. Note that the TP4056 may get hot to the touch due to pulling current. But if you see smoke or a smell, please immediately stop.
Just hold the wires connected for a minute or two.
Now disconnect and check the battery voltage again. If it is rising then we're on track ✅.
Do step 3 again for a couple of more minutes and check again like step 6. Do this until you have over 3 volts which will allow the quest pro's own charger to respond.
Now just disconnect the battery from the TP4056 and connect the battery back to quest pro and use a usb charger to charge it. Again check the battery voltage while not charging, make sure it is rising.
If it goes over 4.1 volt then congrats 👏, your saved the battery 🔋. Now pack the whole thing up and enjoy your achievement.
Try leaving it until it is fully charged before attempting to turn it on.
I hope this helps someone else.