My 8 was just under a year old when I paid £25 to have a new battery. Battery health was 89% and nobody told me it wasn’t necessary to replace the battery, they just went ahead and did it. Actually in my case they didn’t as they broke the internal WiFi antenna, so they gave me a new/replacement phone instead.Does anyone know if you can pay for the battery replacement whilst the phone is still in warranty? My warrenty will be up in January but my battery being at 86%, I would like to get it changed while it’s cheap.