i need a iphone6 battery
where can i purchase a new battery
iPhone 6, iOS 12
First, check to see if the battery needs replacing. Go to Settings/Battery and tap on Battery Health. If it is less than 80% it needs replacement.
Use the Contact Support link at the top of this page to arrange for either an in-store replacement or a mail-in replacement. Here is the pricing—>iPhone Battery Replacement - Official Apple Support