Since official Apple Stores typically do not service the iPhone 4 anymore, you will need to rely on independent retailers:
National or local battery specialty stores often carry "compatible" versions for older models. ⚠️ Critical Purchase Considerations buy iphone 4 battery locally
A successful swap can restore the phone's ability to hold a charge for basic tasks like music or nostalgia, sometimes lasting up to 2 days on standby. How To: Replace the iPhone 4's Battery in 2 Minutes Since official Apple Stores typically do not service
Check small electronics repair kiosks in local malls. buy iphone 4 battery locally