Your phone can run out of power when you are away from home. If you forgot your charging cable you need to be careful. It can be tempting to borrow a charging cable from someone but that can be dangerous.
The charging cable is the same cable you use when you connect your phone to your computer. This is of course well known to the scammers and they could insert spyware on your phone and then access your data and do whatever with it.
It is, therefore important to have a backup plan. You can have a car charger or a backup battery. These products are literally large batteries with ports for connecting phones or other USB devices. Those designed to charge smartphones are usually about the same size as a smartphone and can easily be stored almost anywhere.
The items can be purchased for under $50