Battery upgrading

No, you need to use the correct Apple replacement battery in the phone....even if the other battery might fit.....(and might not). You don't replace the battery yourself, you have Apple or an authorized Apple Service shop perform the service.

If you don't.....

Battery Health will not display correctly

The phone will likely overheat

Apple will refuse to work on your phone in the future, even if you are willing to pay them.

alfan18 wrote:

There are batteries with that capacity are currently available in the market for iphone 7 plus.

Not really.

I remember dealing with aftermarket batteries for an old digital camera. They all claimed to be higher capacity but didn't really work all that well. And in the case of an iPhone 7 Plus, the capacity is limited by the physical size as well as the control of the battery management system.

I personally wouldn't recommend an aftermarket battery for any iPhone if battery service is still supported by Apple for a particular model.

There's always the possibility of going out of spec to claim 5000 mAh. Theoretically almost any lithium-ion battery type could double its rated capacity by going lower and higher in its voltage. But that would require the battery management system handling it, or perhaps playing tricks with the voltage. And dealing with both a higher fire risk and a massive loss in the number of cycles.

But I call BS on anyone claiming to provide a battery with 2100 mAh higher capacity.

Battery Health will not display correctly

The phone will likely overheat

You will see a notice about an "unknown part" on the phone that won't go away

Apple will refuse to work on your phone in the future, even if you are willing to pay them.

But, it's your decision to downgrade your phone.

There is no battery that capacity that would fit in an iPhone 7 Plus.

The iPhone 7 Plus is not user serviceable. If you decide to go that route, you will render your phone completely unsupportable.