My iPhone SE only boots on quick charge

Solution 1:

The battery is dead and needs to be replaced.

If you can only power on and use your phone while it's plugged in, then the battery can no longer hold a charge. It needs to be replaced.

• Fully charged MacBook Air turns off when power cord removed
• iPhone turning off on low battery

"Quick charging" has to do with the current that the charger supplies. It's not a mode you can select. Laptops don't have the ability to quick charge as a typical USB port only provides 5V at 500mA max. You need at least 2.4A to quick charge (12W).

You can try doing a hard reset of the phone, but if the problem persists, it's definitely a failing/failed battery and it will need to be replaced.