The battery is a simple 300 cycle rated model. So that's about 2 or more years and then it loses capacity. Now the decision is to have Apple or someone else change it. I'm a do it myself person, others will go to Apple or iCracked repair.
Hi! I have an iPhone 4S and I've been using it for 2 years. Lately, the battery drained fast. Is anyone with the same problem resolved the issue without replacing their battery? battery is costly