iPhone 6(S)/Plus Battery life on refurbished phone

[Rstoneelf15]

I recently bought a refurbished iphone 6s (IOS 12.2) off Amazon, and have been testing the battery life as I think it is dodgy. I charge it to 100% and then leave in on standby wile i'm at work ( 9 ish hours ) and when return the battery has dropped to 50 % on the first test and the 70% on my second test , where as my old iphone 4s (IOS 9.3.5) only drops 6% and I've been using this phone for 8 years now.

What I'd really like is for other people 'who know they have a good battery' to do this test and so I can compare.

I can set up some guidelines for the testing.

Any help would be great, so if my battery is bad then i can refund my phone.

 

[Banglazed]

Battery life is hard to test and it will vary based on individual usage so it is subjective. Check the battery health on the device in Settings>Battery>Battery Health to see what is the current capacity or on some third party apps such as Coconut Battery etc on Mac. You can compare all the battery life with older iOS but that will be of no use as iOS 12 is not similar or equal to iOS 9. The amount of features and functions can definitely push the hardware limitation of older devices. What you want to test is what is your current battery capacity if it is operating at 100%. If you want to rule out software issues, you can always restore the device to start fresh. I recommend to update or restore via iTunes to minimize issues since it will download the full firmware instead of patch update.

How can you standardize testing? Standard deviation? There are many factors to consider. I would start by updating to the latest iOS 12.3.1 then wait up to 48 hours after indexing to assess your battery life (assuming your usage and condition remain the same).

 

[Rstoneelf15]

Battery life is hard to test and it will vary based on individual usage so it is subjective. Check the battery health on the device in Settings>Battery>Battery Health to see what is the current capacity or on some third party apps such as Coconut Battery etc on Mac. You can compare all the battery life with older iOS but that will be of no use as iOS 12 is not similar or equal to iOS 9. The amount of features and functions can definitely push the hardware limitation of older devices. What you want to test is what is your current battery capacity if it is operating at 100%. If you want to rule out software issues, you can always restore the device to start fresh. I recommend to update or restore via iTunes to minimize issues since it will download the full firmware instead of patch update.

How can you standardize testing? Standard deviation? There are many factors to consider. I would start by updating to the latest iOS 12.3.1 then wait up to 48 hours after indexing to assess your battery life (assuming your usage and condition remain the same).

My phone is the 128GB modal and only has 8GB being used as I only reset it 5 days ago. the battery health is 95%, I close all apps and go into battery health where it says it should last 10 days on standby, I go to work , no activity on phone 9 hours latter , battery has lost 30 - 50 % charge ,,, something must be wrong.

Ill do the update and see how it goes