Apple just released a letter apologising to its consumers for the slowing down of older iPhones due to ageing batteries. As a corrective measure, Apple will be offering discounts on the older batteries when they come in for replacement.

A man holds two boxes for the Apple’s new iPhone X which went on sale today, at the Apple Store in Regents Street in London. Reuters

In the US, the discount is $50, thereby putting the price at $29 for battery replacement for iPhone 6 and phones released after that. In India, that amount will be Rs 2,000 (plus taxes) according to Apple India. The current price as per unnamed service providers is Rs 6,500 all-inclusive. This is a saving of almost Rs 4,500 if you are looking at replacing batteries.

Apple has mentioned in its letter that they would never do anything to intentionally shorten the life of any Apple product. This addresses the conspiracy theories around 'planned obsolescence' whereby a company designs a product with an artificially limited lifetime so that it becomes obsolete or non-functional after a set period.

EXCLUSIVE: @Apple battery replacement cost in India from iPhone 6 & above as confirmed by Apple India is Rs.2000 plus taxes.
Current price of battery replacement as per third party providers is 6500 all inclusive. That's a HUGE discount & should help assuage iPhone users.

— Tech2 (@tech2eets) December 29, 2017

According to Apple, "A chemically aged battery also becomes less capable of delivering peak energy loads, especially in a low state of charge, which may result in a device unexpectedly shutting itself down in some situations."

Apart from offering a discount on the battery, Apple has also promised a software update in early 2018 which will give users more visibility into the health of their iPhone's battery. Apple will also be working towards improving the user experience and avoid unexpected shutdowns as batteries age.

The reason Apple throttled the peak performance speeds was due to the ageing Lithium-ion battery. As the Li-ion battery that powers the iPhones ages, it becomes less capable of supplying peak current demands and the battery drains faster. This is true not just the iPhones but Android phones as well. The peak current demands last for short bursts of time in normal usage behaviour, unless you are running a benchmarking tool where processor cores are firing on all cylinders. In real-world usage, peak demands may be experienced while opening apps or playing that intensive game and so on. So instead of operating at peak clock speed for these tasks, Apple throttles these peak speeds, which will prevent behaviour such as random shutting down of the phone as was observed with the iPhone 6 and 6s in the past.