iphone battery gauge problem! do I need a new phone or just battery?

[beachball doom]

Hi so my beloved iphone SE is having a battery fail :-( The gauge tends to read either 1% or 100%, and sometimes places in between too. It's unclear whether I need to replace the battery or whether it's a problem with the gauge.

I tried running coconut battery while it's plugged into a computer. Coconut battery seems to think it's a bad battery. However I've also seen the phone fail in recent times even after being left on charge all night long. Getting random and unpredictable results to me suggests it's something to do with the charging circuit. I also plugged the charger into the wall via a wattmeter. When it's on 100% I can see that it's not pulling any watts, and it tends to go straight to 100% as soon as it's plugged in... so not promising.

I'm in lockdown right now so putting it in for repair somewhere is going to be difficult. I've replaced an iphone battery before so I know what I'm doing, and I'm prepared to order one online. But I don't want to waste my time if it's actually the phone. What should I do?

 

[Spetsgruppa]

Happened to my iPhone 7 Plus before because of liquid damage. It either shows 100% or 1%. Better to get it checked and repaired.

 

[BugeyeSTI]

If you want to continue to use the device I'd replace the battery with a quality 3rd party part if you can't go to an Apple store to have it done.

 

[beachball doom]

Uh oh.... so shortly after I ordered a new battery on ebay, the phone completely went dead. It won't even turn on when plugged to power. I guess this means the battery is worse than kaput, absolutely finished. But I need to use the phone in the mean time. Is there any way I can use the phone?

 

[weaztek]

I was lucky enough to have a computer/phone repair shop across the street. I backed it up, reset it to factory new settings, and dropped it off. An hour later I paid them ~$50, picked it up, and restored it from my backup.

 

[BugeyeSTI]

Uh oh.... so shortly after I ordered a new battery on ebay, the phone completely went dead. It won't even turn on when plugged to power. I guess this means the battery is worse than kaput, absolutely finished. But I need to use the phone in the mean time. Is there any way I can use the phone?

Not until you replace the battery..