Can’t believe I’m even contemplating an iPhone .
Does anyone have a battery case on theirs? I don’t mind making a phone thicker I don’t want it longer.
Are there any options for this? When you consider how small a battery is I don’t see why these things have to be so bulky.
Anyway how much extra life does it give you?

I got one for my iPhone 6 a few months ago.
This one
I paid £25 but it’s now £19
At the time my battery was pants and it kept my phone alive. Obviously the phone was bulkier and heavier but that didn’t bother me and it does protect it quite well.
I was more than happy with it. It has a lightening plug so can charge phone through the case.
However I’ve just replaced the battery with a new one so not using the case at the moment.
Only downside is that it doesn’t allow the phone to be used as a usb device so Apple CarPlay doesn’t work with the case on etc. Easy to slip it out. Headphone socket is accessible.
It shouldn’t need one with a decent battery in the phone though.
How much extra life? 140% according to the link.