Users expressed outrage over the company's under-the-table throttling practices, firstly because Apple didn't explicitly inform customers that this would happen eventually, and because a large portion of affected users claim that Apple may be doing this to force users into upgrading to the newest iPhone model. The company's admission stoked long-held speculation that Apple slows its devices to drive sales of new models. It's running slow, but is it running slow because iOS is throttling it?
The reason Apple has gone for this feature is that irrespective of the iPhone model, the battery will be lose its capacity to hold charge over time.
There's also a way to test how worn your iPhone's battery is.
If you have the update you will see a new page in the Battery section.
According to Apple, the iPhone's battery is created to retain up to 80 percent of its original capacity at 500 complete charge cycles, so if the full charge capacity is less than 80 percent of the design capacity, or the recharge cycles exceed 500, then your battery is considered worn. If it is under 80 percent it will be considered "significantly degraded". However, the only benefit I'd get from a battery replacement right now is increased lifespan since the device isn't being throttled. Some users have also reported that, with the new beta version, they've actually had a few gigabytes of storage returned to them.
Eventually, this same feature will be released as an official update, once the beta period has ended sometime this spring. You can do that here. While you can easily roll back from running the beta, it's possible for the beta to cause havoc in the meantime.
A battery health function in the Settings app is another big addition, which will let users check the health of their iPhone's battery without downloading a third-party app or going to the Apple Store.
If your iPhone's performance is being throttled, you will see a statement similar to the one above, where you can disable the feature if you want. Click on this to find out more about your battery.
The reports says that Face ID is coming to the LCD iPhone as well as the flagship OLED ones, and that Apple is diversifying suppliers for the 3D face recognition modules needed for the feature ... "You can't turn this back on until you get another unexpected shutdown, at which point it will automatically be re-enabled". While the reason behind the slowdown was supposedly put in place in order to protect aging phones from random shutdowns due to battery issues, the majority of their user base was up in arms due to the lack of transparency regarding the slowdowns.