Extreme Battery Capacity Loss?

[Gorge]

My wife's iPhone 6 has had some major battery loss issues. I took it to Apple 6 months ago and they said it was normal and the battery drain could be software related. We reset the phone, restored, and did the other battery resets that were recommended.

Fast forward to last night. My wife said her phone died after 2 hours today. I checked coconut battery and the stats were:

Charge Cycles: 512
Current Charge: 100%
Full Charge Capacity: 4XX (I can't remember now. I took a screen shot but the mouse was hiding the last 2 digits)
Design Capacity: 1810 (23.9%)

I wasn't sure if coconut battery was off so I installed the battery life app on her phone and it says:

Capacity: 500 /1810mAh (28%)
Battery Charge: 500/500mAh (100%)

Clearly the battery is defective since Apple says a 300-500 charge cycle iPhone has 80% capacity. I'm going to take it in this Friday and see if they will replace it for free, but is there any other information I should bring? The phone is an iPhone 6 so it has no warranty left. I would hope they would do a courtesy replacement for us.

Or perhaps I'm blowing this out of proportion and this is normal. Thoughts?

 

[Minho]

That battery is beyond dead, from a usefulness point of view. Any battery below 70% Design Capacity has a noticeably short lifespan. When you get to ~50%, it barely lasts more than a few hours. Everybody touts Apple repairs as using the best parts but you clearly got a dud here. I would certainly ask for complimentary replacement.

 

[Gorge]

That battery is beyond dead, from a usefulness point of view. Any battery below 70% Design Capacity has a noticeably short lifespan. When you get to ~50%, it barely lasts more than a few hours. Everybody touts Apple repairs as using the best parts but you clearly got a dud here. I would certainly ask for complimentary replacement.

Just took it to Apple. They ran their diagnostics and it said it was 83.1% capacity. They wouldn’t replace it even if we paid for it. They said it’s an app. Hard to believe since she only has 10 apps on the phone

 

[Minho]

That's odd...coconutBattery doesn't invent the numbers, it just reads them directly from the battery (it has a small circuit board inside). There's a huge difference between ~25% design capacity and 83%. Download iMazing and test it again to see. If need, be, backup the phone, do a full factory reset and test again to see if it is truly app related.