Motorola phone batteries

I never realized the importance of my motorola phone batteries till a couple of days ago. I was hanging out with a couple of my friends at the beach. We had an awesome day, the surf was great. Everything was going well till I went to call my parents to come pick me up and my battery was dead. I ended up spending an extra hour at the beach and got a nasty sunburn. Goes to show that you always need to check to see if your batteries are good or not.