[waffl]

I replaced an aging battery on my 6S Plus a few months ago myself and installed iOS 11 at the same time (figured it was a good opportunity to do both together).

Immediately I noticed my phone was basically unusable, incredibly slow, everything was crashing or locking up completely, I couldn’t believe it. I thought iOS 11 was the culprit, and even did a complete reinstall without restoring any backups to no avail. Finally, I noticed a slight dark spot on the LCD - the brand new battery I had bought was already bulging and in bad shape.

I sprung for a better quality battery from ifixit and immediately the phone was running like brand new again. I thought the cheap battery had been supplying an unstable current, but perhaps there is indeed an issue with the software itself.

One key thing I realized - ANY battery work done outside of Apple’s official repair means they will never work on your phone again. So if you care about having Apple do any kind of work on your phone (even if totally unrelated to battery), you will have to get it replaced by them.

[Turing_Machine]

+1 on ifixit. I've yet to be disappointed with anything I've purchased from them, and I've done probably a dozen battery swaps, screen replacements, etc.

You can find parts for less, but it's really a roll of the dice as to what you're going to get.

[Synaesthesia]

It’s very hard to get quality batteries outside of Apple which kind of sucks for iPhone repair. Yeah the 3rd party ones usually suck.

[waffl]

Actually I feel almost any component in general sadly. I had to replace the front camera assembly as well and after trying almost four different parts from multiple vendors and none match the quality of the original.

Another thing I learned is that Apple would replace the entire display and front assembly (front camera, earpiece, speaker, brightness sensor, proximity sensor) for only ~ $150. However, due to the third party battery they couldn’t work on it anymore.

[Synaesthesia]

Yeah the displays and touch panels are also sometimes inferior. That’s a real shame about your phone sorry.

[jakobegger]

I had bad luck with original Apple batteries and got a good third party battery, so your milage may vary.