My battery was draining very fast even when UNUSED and in LOW POWER MODE. This was happening even in AIRPLANE mode (i.e. overnight, unused, in Airplane and Low Power Modes both enabled).
I got the phone services and the service guy told me the problem was the U2 chip, so I paid to have it repaired. But now it should have the new U2 chip, but it still drains the same (i.e. very quickly).
Can the battery be the problem of fast draining too?
The guy that repaired the U2 chip now tells me the battery is the problem, but now I doubt everything he says.
Best Answer
Short answer
Yes, a battery's condition can most definitely explain why it is draining fast. iPhone batteries are consumable components that become less effective as they age. They have a limited lifespan and their capacity will decline over time, eventually leading to lower performance for your iPhone.
Long Answer
You will get lots of opinions on batteries, so when it comes to Apple products I always encourage users to read what Apple has to say on the topic.
Apple also recently published iPhone Battery and Performance.
To partially quote Apple:
I would encourage you to read the entire article.