[lips]

I carried a G1 with two spare batteries when doing documentary work. It was lovely. I didn't have to hunt for outlets or deal with using the phone while plugged into a battery pack.

If the phone is a widely used model, it's often not difficult to find new-old stock for a while.

I gave this list of "not cares" a several year window of context. It's pretty obvious OP doesn't want a bag-phone, but might be perfectly happy with the form factor of an iphone 4/5. Not a novel complaint.

[usaphp]

Did you tape those batteries to your phone? How did you carry them with you all the time?

[dom0]

The invention is called "pocket" and/or "bag". I think the patents have expired though...

[rubber_duck]

You can buy a portable charger, not as convenient but also designed for carrying around unlike batteries (honestly carrying around an unprecedented fully charged battery in pockets (bag or clothes) sounds dangerous)

[Laforet]

It's not quite like E-cig users and their naked 18650 cells.

[pix64]

No more dangerous than keeping your phone in your pocket or bag.