Keep Your Old iPhone as a Backup

The first thing you need to know is that you don’t necessarily have to give your old iPhone a new use, at least not just yet.
Instead, you can keep your iPhone for yourself. Use your new iPhone as much as you want, and keep your old one as a spare in case you need it.
That said, you shouldn’t just put an iPhone in a box and forget about it. Apple has a few tips on how to store an iPhone properly. First, you must ensure it’s stored in a room with the right temperature. Apple suggests that you place your iPhone in a moisture-free environment, with a temperature of less than 32° C (90° F).
Moreover, charge your iPhone to precisely 50% battery, but only if you plan to store it for six months or longer. This will prevent your iPhone’s battery from suffering too much wear and tear.