What causes my phone to shut off at a high charge(73%)?

[MrMayonnaise]

I have a Samsung Galaxy Note 5 and I recently had replaced the battery to hopefully get a longer charge out of it. The battery was fine until about 5 days ago when It would shut off at around 60% to 30%. When I plugged in the charger the percentage would drop to around 89% from 92% and would keep dropping every time I would unplug and re plug the cord. I looked it up and thought the solution would to simply re calibrate the battery percentage. This didn't help. Now it'll charge to 100% then Power off once it reached 73%-ish. When it shuts off there isn't the animation of the Samsung logo and such it just turns black, like you pressed the power button, or pulled the power cord of a TV. One thing that comes to mind is that the night before all of this started to happen there was a storm that caused the power to turn off for like half a second then back on, my phone was plugged in charging at the time of the outage. I don't know if this has any relevance but I thought I should include everything. What I'm asking is if this is a problem of the installation of the new battery, that the battery sold to me was faulty, or if the storm in some way damaged it.

Phone: Samsung Galaxy Note 5
Android Version: 7.0
Battery Size: 3000mAh
Age: Around 2-3 years

Thanks for any help sent!

 

[Rukbat]

The battery was fine until about 5 days ago when It would shut off at around 60% to 30%.

That's indicative of a dendrite (Lithium Battery Dendrite links if you're interested) and it means that the battery has to be replaced.

thought the solution would to simply re calibrate the battery percentage.

Which requires that the phone be rooted.

This didn't help. Now it'll charge to 100% then Power off once it reached 73%-ish.

That sounds as if you messed up the calibration somehow - and the dendrite is appearing during charge now, as well as during discharge.

One thing that comes to mind is that the night before all of this started to happen there was a storm that caused the power to turn off for like half a second then back on, my phone was plugged in charging at the time of the outage. I don't know if this has any relevance

That shouldn't cause any problem - unless there was enough of a surge on your particular line to blow things on the motherboard, in which case it wouldn't pay to repair the phone. (You can buy a gently used one for about $125 or less - about what most shops will charge to replace it with a cheap Chinese copy.

What I'm asking is if this is a problem of the installation of the new battery, that the battery sold to me was faulty, or if the storm in some way damaged it.

The battery is probably defective. The motherboard may be defective. The only way to tell is to put a known-good battery in it and see what happens.

That's why repair shops exist - they have known-good parts to swap in.