The thing with spare batteries is, they're only useful if you also have a standalone charger, and most people neglect that. If you have to use the phone itself

The thing with spare batteries is, they're only useful if you also have a standalone charger, and most people neglect that. If you have to use the phone itself to recharge them, then any time you've used up several spare batteries, getting them all charged up again is a huge pain. I have a standalone charger that plugs into the wall, and half a dozen spare batteries. Rather than plug my phone in to charge, I swap its battery with the fully charged one in the charger. This means I never worry about discovering my phone is almost dead when I'm about to leave the house; recharging to full is instantaneous, rather than tying my phone (and by association, me) to a single spot for hours. Doing things that drain the battery quickly are no longer a big deal. And if I'm going to be traveling for awhile without the ability to plug in, I can take as many batteries as I'll need.