I am a developer of hardware electronic devices and have a masters degree in electronic engineering.
A few things in the defence stated are definitely nonsense.
Electronic components don’t need to be protected from being underpowered. In 15 years of working with ultra low power designs I’ve never seen anything damaged by low power. A brown out condition may degrade performance or cause temporary malfunction but won’t break anything permanently.
Apple are almost certainly already using a buck/boost switched mode converter to eek the most energy possible out of the battery already. That means a surge in demand current will just drain the battery faster. Not cause a brown out/failure, unless perhaps almost completely discharged.
I have suspected that apple have been doing intentional slowdowns since iPhone 3G. The time taken for a processor to do something is directly proportional to the number of instructions it executes. So if an app took 100ms to refresh a screen on your phone when new, and now takes 2s, it is either doing 20 times as much, or something is slowing it down. For sure, newer versions of operating systems provide more functionality and do more. But they don’t become 20x more wasteful. Embedded system engineers have huge pressure to extend battery life. That includes writing efficient software, and those who’ve worked in that industry will know exactly what I mean. PC programmers had the luxury for a long time of ignoring this, thanks to Moore’s law and big power supplies. Apple are still using an arm processor without any groundbreaking technology changes. That means the new iOS versions will need to be coded efficiently to look good on the new devices.
Many people aged 30+ have been conditioned into thinking that computers just slow down and they need to upgrade hardware every so often. This has mostly come from using desktop pcs. Embedded devices are a whole different story. Correctly designed software should work absolutely fine with very similar performance to the initial condition.
I could bore you with lots more technical discussion but there are some very simple tests you can do to check it:
In a normal warm environment with the battery fully charged, do you see slowdowns?
With the power lead plugged in, do you see slowdowns?
If so the slowdowns have nothing to do with the battery.
Dave
while there are other factors that have significant impact on energy consumption in a phone, such as the cellular radio or screen, cpu clockspeed and cpu voltage are directly connected. the higher the clockspeed the higher the voltage needed to sustain it.
for example, just look at the A8 series of devices: ipod touch 6gen, iphone 6, ipad air 2 come with the same A8 cpu generation and manufacturing process. differences can be observed in the applied clockspeed (voltage) and number of available cores.
The tiny battery of the ipod touch is possible because there is no cellular connection to power and is has a lower clocked A8 than the iphone 6. The air2 with its massive battery (possible simply because of its size) can drive a huge screen, cellular if needed and a high clocked triple core A8 cpu on top of that.
Now, keeping the device design as light and thin as possible clashes with the physical possibilities of todays battery design though. Apple walks a very thin line here, clearly sacrificing performance in favor of obtaining the sleekest design possible.
I can well imagine that the expected "normal" 3 year lifespan of a regular lion battery gets drastically reduced by these design choices, forcing Apple to reduce power consumption before the 3 year mark by tweeking the only factor not directly visible to the end user: reducing clock speed.
That being said, I suspect that with todays battery techology coupled with Apple's device design it is nearly impossible to keep the idevices running at peek performance for much longer than they do now ...
Forcing people to buy new phones much earlier is just a nice side effect of this balancing act ...
