So which phones would that be where the batteries cannot be replaced?
Apple's iPhone are designed with battery that should not be replaced by the end-user. The only official policy is that you should bring a phone with a dead or dying battery to the shop for replacement, whereupon the salesperson will try to persuade you to buy a new phone because replacing the old battery is almost as expensive as the newest shiny toy.
You can try to replace them, but it's non trivial, you need to actually disassemble the phone, which might void your warranty.
Compare with any other brand sold in Europe:
You just to :
- buy a replacement (either the original part from any phone shop, or by a 3rd party like mugen)
- power off the phone
- open the battery lid (just pushing a button)/swap the batteries/close the lid
- power on
- don't forget to throw the battery in the appropriate recycling bin instead of putting it into trash.
(Please note: air-mailing lithium batteries has a special regulation. Some postal service just refuse to handle them "on security ground", even if they are standard conformant, the proper paperwork is filled, and (like everyphone battery, unlike some modelling batteries) the protecting electronics are actually embed inside the battery itself. That's plain stupid. And it might block your possibility to return the battery for RMA)