To recap, the iPhone 6s was suffering through an unexpected shutdown issue previous year, prompting Apple to release a fix in iOS 10.2.1 which solved the problem for most. The problem he found was that iPhones were slowing down as their battery life decreased, and the issue was widespread enough to affect even the iPhone 7.
All batteries will eventually start to fail - they have a limited lifespan.
If the iPhone is slow because its processor performance has been reduced to mask a deficiency in battery power, Poole says: "This fix will also cause users to think, "my phone is slow so I should replace it" not, "my phone is slow so I should replace its battery".
Some consider this a deliberate move by Apple to slow down older phones via iOS updates. Last week, a Reddit user whose iPhone 6s had been slowing down found it received a massive performance boost when they replaced the battery, leading to an extensive thread on the subject.
Reddit users explained that was because Apple, with iOS 10.2.1, dynamically lowered the maximum clock speed of the processor.
The effect was more pronounced with iOS 11.2 and was seen with the iPhone 7 as well, which was launched only a year ago.
"Another popular benchmarking company Futuremark - the company behind benchmarking apps like 3DMark - recently came out with its own share of findings". Geekbench's conclusion is that a software tweak has introduced throttling so as the battery in an iPhone declines, Apple throttles a phone's performance to decrease power draw and thereby preventing the handset from draining its battery too quickly.
The increase in prices is applicable on all iPhone models except the iPhone SE as the Apple assembles the device in a Bengaluru-based facility with its Taiwanese manufacturing Wistron Corporation.
'This will likely feed into the planned obsolescence narrative, ' said Primate Labs researcher John Poole.
However, the shorter the battery life and the more a user has to charge it, such as topping up during the day as well as charging over night, the faster the battery will age in relation to the smartphone.
Apple did not immediately respond to a request for comment.