New iPhone 13 Battery from iFixit stuck at 0% remaining

it sounds like you might have a defective BMS board i'd try some diagnostic software just in case but i recommend contacting ifixit support to have it replaced / exchanged.

Hi Marco,

As @tech_ni has said, on phones made after the iPhone X Apple started pairing the battery to the logic board. It's my understanding that battery health information will no longer be available, but regardless the battery should still work correctly. I assume that includes displaying the percentage of charge available, so it appears the battery you got isn't working correctly. Since all iFixit batteries have a one year warranty, you should be able to get a replacement by contacting the iFixit Store at support@ifixit.com.

Just for completeness, there are three ways to get your battery replaced and have it work the same as it did before. The first and easiest, of course, is to simply pay an Apple authorized repair facility to replace the battery. Secondly, you could avail yourself of Apple's self repair program, which is generally cheaper, but you still have to buy the battery from Apple and rent their equipment to do the repair.

Finally, the aftermarket industry has come up with a workaround. Since the pairing can only be done by Apple, the idea is to keep the existing BMS (Battery Management System) circuitry and transfer it to a new battery cell. Basically, you cut the BMS off from the battery cell and solder/spot weld it onto a brand new cell. Aftermarket batteries are now available both with and without the BMS just for this purpose.

Prior to the iPhone 11, the battery data could be read and written from the BMS, allowing you to read and modify the value of the battery capacity percentage and the cycle count. So in those cases you swap over the BMS and then use a device programmer like the QianLi iCopy or JC V1S to reset the battery statistics. If you don't do that, the new battery will still report the old battery data and will display incorrect information under Settings.

Unfortunately, Apple didn't stop there. As of the iPhone 11, they started encrypting the battery data so those programmers I mentioned earlier can no longer reset the data when a new cell is put in place. Once again, though, the aftermarket developers have come up with a solution. It's called a tag on flex, and basically it's a tiny circuit that plugs in between the battery and the motherboard and allows you to clear the battery data. You simply attach it to the battery, clear the data, then install the battery and the tag on board into the phone; the tag on board stays inside permanently. After that the battery will once again work the way it would if Apple had installed a new battery.

So the short story here is that Apple is continuing and indeed accelerating it's anti-repair tactic of parts pairing with the intent of making it impossible for anyone but them to repair their phones. There are workarounds for some of their tactics, but not all; Face ID and Touch ID are prime examples and they're extending that strategy to batteries and screens now.