iPhone 12 Pro Max — poor battery life

if you keep it for an overnight charge your battery health will go poorer earlier than was expected of it and if you are not havin apple care you will end up replacing the battery at a considerable cost sooner. The battery performs best at less over charges & less over heat. Overnight charges are bad for all batteries does not matter iphone or other brands. You might want to see these threads to tweak it to last longer:

About Optimized Battery Charging on your iPhone - Apple Support

Batteries - Maximizing Performance - Apple

How can you "not use" your phone if it's fully charged?

If your battery is being used within "hours" what does the Battery pane say is using the energy?

Does the issue continue in low power mode?

There's nothing to "make right" here, though Apple Support can help you further:

Contact - Official Apple Support

The best way to find out is to go to your battery health and see what is consuming your battery, you have tabs for “last 10 days” and “last 24 hours” there it will tell you what app or what activity of yours consumed the battery in %. It will also show which apps “background” is consuming battery. You might want to then disable backgrounds of app’s you don’t want them to be active. However’ after doing all this you might still consume more battery because of screen time. Tweak the best option for you. However, I still feel the 12 Pro Max battery is not that great or probably the latest update wrecked it. I have attached a photo sample view

Found why mine was draining so quickly, Amazon music app ! No idea why is as I’ve had the app for a long long time, but found it was using 75% of battery ! If you go to battery in settings, you can see what is using most of the battery. I updated aAmazon music app and been fine since

Yeah mine too, I charged my phone yesterday at the evening to 74% and used it for about an hour down to 60% and when i went to sleep and woke up the battery was completely dead. Pretty weird right? And i’m using iPhone 12 pro max

Even if you tweak all that including, it will still drain quiet fast. I think the battery is poor in this design, and is unable to cope up with increased memory (I have 256GB) and watch synch. I had 11Pro Max and it was doing OK with the same app's and watch synch.

Nope. Bunk.

Batteries can be charged any time for as long as you like. It's especially useful overnight because not many users take their phone to bed.

Charge the battery when not in use. You can not overcharge it.

I am in the UK, bought the 12 pro max 128gb 2 days ago and i just cannot understand how awful the battery is . Even without a single call, the battery is running out pretty fast. Is this normal for a brand new phone (flagship) fully charged?

I had the same problem with the excact same storage space, but i do have some tips for you: turn On auto brightness or just don’t have it on max all the time no matter how much you want to, I keep it at about 40-60% brightness and that gives me about 20-40% more if you don’t use Bluetooth that often i reccomend turning off Bluetooth Even though it doesn’t extend battery life that much and you could also turn On battery staving mode or glose your apps after you use them if you’re not roing to use them right after. Hope this helps!

I charge my phone at night and wake up with only half charge replenished. Example: I plugged my phone in at 10:45 pm last night and it only charged to about 30% by 6:15 am so I’ve kept it charging and now at nearly 9am it’s just above 50%.

I checked my charger and made sure it’s plugged in. It can charge my brother’s iPhone completely in about an hour or less.

I disagree- the optimization charging prevents your phone from charging until you need to use it so unless that’s off, plugging it in does nothing.

Additionally, my mother is obsessed with plugging in her phone and charging to 100% all the time. Anything less than 90% means she needs to charge. Out of my entire family and friends who use iPhones, she’s had more problems with hers and has had to buy more phones due to bad battery.

Same here, I changed my old phone hopping to get better battery life. I bought iPhone 12 Pro Max a week ago and I had to charge 3 times my phone in 24 horas. Furthermore, If I am using it gets too hot, same when is charging. I am really disappointed. Planing to take my phone to iPhone

That's why Apple has an "Optimized Battery Charging" feature.

FWIW, I've kept my past phones charged to 100% as much of the time as possible and have never seen a drop in "battery health" until the phone was over 1.5 years old.