Replaced battery - new battery will not fully charge!

Replaced old dead battery with a new one from ifixit. After 24 hours it would not charge more than 85%. Once disconnected from the charge the battery would discharge and be dead in a matter of hours. No apps are running and everything (location services, wifi, phone, Bluetooth, etc) is turned off.

Ifixit decided the first battery they sent me was defective so they sent me another. The 2nd new battery has the same problem. It charges very slow and never reaches beyond 80% charge. It will slowly discharge once disconnected even though the phone is not used and nothing is being run on it.

I have used different chargers so that is not the problem. The chargers are all apple products. I also tried charging via USB port. Same thing happens. Slow to charge and discharges when disconnected.

I even did a reset of all the phone settings. No luck. Could I have received 2 defective batteries from ifixit?

Any suggestions