Iphone 13 pro max hard to sell ???

because i unable to sold 

i still have 1x Gold and 1x Black both are 256GB Pro Max

My phone arrived on 9th October 2021 which was the first batch. Ive been monitoring the battery health to see if it drops and today it went down to 99%

So 1% after slightly over a year. Usually charge my phone when it hits 20% and charge to 80% but of course there are times when I only start charging the phone after it has dropped below 10% and also times where I forget to unplug it and it fully charges to 100%

Hope it drops only a percent every year so it will still be above 95% after 4 years when I replace this phone