Without a doubt the biggest battery drain.

What drains the battery of an iphone the fastest. A lot of things can cause your battery to drain quickly. If you have your screen brightness turned up for example or if youre out of range of wi fi or cellular your battery might drain quicker. There have also been reports of iphones overheating.

Both charging the battery in the cold and using the iphone in the cold. Battery drain has been a persistent bugbear for iphone owners in recent years and that looks unlikely to change given apples risky decision to launch the iphone 12 range with smaller batteries.