5S Batteries are not compatible with 5C

I am often seeing sales on eBay for batteries for 5C/5S.

A 5S battery does not work in an iPhone 5C, It causes the phone to restart every 5 minutes or so.

A 5C battery will work in a 5S as the 5S can handle the higher Whr.

iPhone 5C requires 3.45Whr and 5S required 3.93Whr.

I am sick of suppliers sending me 3.93Whr batteries for 5C when they do not work, They do not seem to understand the slight difference between them,

Hope other technicians encountered same issues as I am having!