Your iPhone no longer makes it through the day, gets warm and simply shuts off at 20 percent? That is almost always the battery, and the good news: it doesn't have to mean a new phone. The honest answer to battery swap or new purchase depends on three things: battery health, the age of the device and your needs.
Under Settings, Battery, Battery Health your iPhone shows the maximum capacity. As rules of thumb:
Important: a weak battery says nothing about the rest of the device. The chip, camera and display age much more slowly than the battery.
If your iPhone is three years old or younger and you are otherwise happy with it, a battery swap is almost always the most economical solution: for a fraction of the device price, your iPhone feels like new again, and you produce zero e-waste. At our workshop the battery is swapped in about an hour, in Basel, Bern and Solothurn even without an appointment, with a warranty on the repair.
A new purchase (or better: a certified refurbished device) is the better choice when several points come together:
Then the battery swap no longer pays off, because you are investing in a device that will soon limit you anyway. Stepping up to a one to two year old refurbished model often costs surprisingly little; check the prices in our smartphone range.
Even with a weak battery, your iPhone is worth money. You can sell it or trade it in directly and put the proceeds towards your next device. That way the old phone finances part of the upgrade, and after professional refurbishment it gets a second life with us instead of a drawer.
Battery below 80 percent and otherwise happy: get it swapped, one hour of effort. Device at its limit overall: upgrade to refurbished and get the old device credited. In both cases, you don't have to buy a brand-new device at full price.