SEVEN clues signal that your iPhone is making itself run slower – all to protect the battery.
If you’ve got an older Apple blower, it might be limiting itself with some surprising changes.

It’s all part of a feature called iPhone Performance management.
And yes, it might really be slowing your iPhone down – you’re not going crazy.
It might sound terrible, but it’s designed to help your iPhone work better for longer.
The lithium-ion battery inside your iPhone gets worse over time.
That’s not an Apple-only problem: this common battery type will degrade as you charge it up and use it. Excessive heat can also speed this process up.
For instance, after about two years (or 500 full charge cycles), you’d expect the battery to hold just 80% of its maximum charge when it was new. That means bad battery life – and charging more often.
And this chemical ageing can cause other problems too.
“For a phone to function properly, the electronics must be able to draw upon instantaneous power from the battery,” Apple explains.
“One attribute that affects this instantaneous power delivery is the battery’s impedance.
“A battery with a high impedance may not be able to provide sufficient power to the system that needs it.
“A battery’s impedance can increase if a battery has a higher chemical age.”
When the impedance is high, the voltage can drop – and potentially fall so low that normal functioning isn’t possible.
This can play havoc with the electronics in your iPhone – and can cause the gadget to shut down entirely.
So Apple uses iPhone Performance Management to avoid these shutdowns.

That means having your iPhone intentionally slow down.
“iOS will dynamically manage the maximum performance of some system components, such as the CPU and GPU,” Apple said.
“As a result, the device workloads will self-balance, allowing a smoother distribution of system tasks, rather than larger, quick spikes of performance all at once.
“In some cases, you might not notice any differences in device performance.”
WHY DO BATTERIES GET WORSE OVER TIME?

Here's what you need to know
Picture Credit: Apple / The Sun
When the Performance Management feature is working at “extreme” levels, you might notice certain surprising effects.
According to Apple the seven signs to look out for are:
Longer app launch times Lower frame rates while scrolling Backlight dimming (which can be overridden in Control Centre) Lower speaker volume by up to -3 dB Gradual frame-rate reductions in some apps During the most extreme cases, the camera flash will be disabled as visible in the camera UI Apps refreshing in the background might require reloading upon launchApple also confirmed that there are several features that won’t ever be affected by performance management.

So if you’re experiencing issues with any of them, something else is to blame.
Those features include:
Mobile call quality and networking throughput performance Captured photo and video quality GPS performance Location accuracy Sensors like gyroscope, accelerometer, barometer Apple PayFor instance, bad call quality is most likely due to you having poor signal – or because too many people are using the same network as you.
WHAT NOT TO DO!

Letting your iPhone get too hot can permanently damage your iPhone battery...
Apple says avoid these activities…
Leaving your device in a car on a hot day Leaving your device in direct sunlight for an extended period of time Using certain features in hot conditions or direct sunlight for an extended period of time, such as GPS tracking or navigation in a car, playing a graphics-intensive game or using augmented-reality appsIf your iPhone is getting hot, Apple says you might notice these changes…
Charging, including wireless charging, slows or stops The display dims or goes black Mobile radios enter a low-power state; the signal might weaken during this time The camera flash or other camera features might be temporarily disabled In some apps or features, performance is reduced with lower frame rates or increased processing timesPicture Credit: Apple
If you’re worried about your iPhone battery, you can actually check exactly how healthy it is.
Just go into Settings > Battery > Battery Health and look at the read-outs on that page.
You can see the battery’s maximum charge capacity compared to when it was new, as well as how healthy it is.
It’ll also flag up if your iPhone is not longer able to operate at peak performance.

If you’re having trouble here, you don’t necessarily need to rush out and snap up a brand new iPhone.
One cheaper option is to get a battery replacement from the Apple Store, which typically costs less than £100/$100 (unless you have a very new iPhone).
That should not only give you like-new iPhone battery capacity, but it can also improve your mobile’s performance too.
And it might let you put off paying for a big iPhone upgrade for a few more years, saving you money.
IPHONE BATTERY SWAP – HOW MUCH WILL IT COST?

Here's how much you'll pay for iPhone battery replacements in the UK and the US..
iPhone 5 Series
iPhone 5S: £N/A / $69iPhone SE Series
iPhone SE (1st gen) – £N/A / $69 iPhone SE (2nd gen) – £65 / $69 iPhone SE (3rd gen) – £65 / $69iPhone 6 Series
iPhone 6 – £N/A / $69 iPhone 6s – £N/A / $69 iPhone 6s Plus – £N/A / $69iPhone 7 Series
iPhone 7 – £65 / $69 iPhone 7 Plus – £65 / $69iPhone 8 Series
iPhone 8 – £65 / $69 iPhone 8 Plus – £65 / $69iPhone X Series
iPhone X – £N/A / $89iPhone XR/XS Series
iPhone XR – £85 / $89 iPhone XS – £85 / $89 iPhone XS Max – £85 / $89iPhone 11 Series
iPhone 11 – £85 / $89 iPhone 11 Pro – £85 / $89 iPhone 11 Pro Max – £85 / $89iPhone 12 Series
iPhone 12 mini – £85 / $89 iPhone 12 – £85 / $89 iPhone 12 Pro – £85 / $89 iPhone 12 Pro Max – £85 / $89iPhone 13 Series
iPhone 13 mini – £85 / $89 iPhone 13 – £85 / $89 iPhone 13 Pro – £85 / $89 iPhone 13 Pro Max – £85 / $89iPhone 14 Series
iPhone 14 – £95 / $99 iPhone 14 Plus – £95 / $99 iPhone 14 Pro – £95 / $99 iPhone 14 Pro Max – £95 / $99iPhone 15 Series
iPhone 15 – £95 / $99 iPhone 15 Plus – £95 / $99 iPhone 15 Pro – £95 / $99 iPhone 15 Pro Max – £95 / $99iPhone 16 Series
iPhone 16 – £95 / $99 iPhone 16 Plus – £95 / $99 iPhone 16 Pro – £109 / $119 iPhone 16 Pro Max – £109 / $119Picture Credit: Apple