I have tried the following troubleshooting steps:

- Leaving the battery to charge for an extended period.

- Disconnecting and reconnecting the battery cable multiple times, including leaving it unplugged for over 2 minutes to drain excess charge.

- Attempting to force boot into recovery mode.

None of these steps worked. When I reinstall the original battery, the phone boots instantly (though the old battery has its own capacity issues). This indicates a BMS or communication failure on the new replacement battery. Furthermore, during the process of removing the faulty new battery to troubleshoot, the battery was bent and the back glass was damaged, resulting in a physical injury from glass fragments.

Has anyone else experienced this specific 'red lightning bolt' failure on a new OnePlus 8 battery despite the original battery still being recognized by the motherboard? I am looking for confirmation if this is a known BMS defect.

⟐ Answered febbraio 07, 2026 at 5:28 GMT-7

I recently replaced my Oneplus 8 battery using an iFixit battery and it was a very successful replacement.

I attempted the calibration using the guide from iFixit and many various sources to calibrate the fuel gauge. That first time, I noticed that the battery lasted a long time in general, and lasted a while at 1%. It died, I plugged it in and when it reached 1% again I turned it on and left it to charge.

This worked well for 1 day - but after a few days, the battery percentage would drop quite quickly to 1% and then last 2 to 3 more hours on 1%. Since then, I have attempted the calibration process a few times but I can't quite get the calibration to stick.

• Is there anything else I can try or am I missing anything in particular?
• Could there be any fault with the battery? If so, can I diagnose it in any way?

Any guidance would be much appreciated. I was so hopeful to bring my phone back to life from its poor battery life, but I'm sad to see that it's even worse now :(

⟐ Commented novembre 12, 2025 at 6:01 GMT-7

I learned a couple of things:

• I tested the voltage of the battery with a normal multimeter. I could confirm it wasn't dead and it was reading 4.2V
• The loudspeaker/daughterboard cover and motherboard cover can both be removed and the phone will power up fine despite having some contacts on the board. Not sure what they're there for.
• After the motherboard swap, I couldn't get the phone to start with the battery disconnected while plugged into even an "adaptive fast charg[er]," but it did vibrate and try to show the lighting/power icon.
  • That may be a good way to test whether the display is working or not as it also gives the tactile feedback

I'm not sure what the odds are there's someone out there that knows how to "micro-solder" or if it's even possible to remove the "hard drive"/storage and swap them across motherboards, but if anyone knows anything along that line of inquiry that would be super helpful. Thanks!

⟐ Answered ottobre 25, 2024 at 0:56 GMT-7

⟐ Answered luglio 27, 2024 at 9:57 GMT-7

⟐ Comment deleted settembre 29, 2022 at 0:24 GMT-7