Many a time there are situations, when the phone battery ran out when we needed more. Many people get annoy when the mobile battery gets low. There some fact that you may not know about your cell phones, your mobile has reserve battery that you can utilize when your cell phone battery goes down or in the situation when it is important.
To activate the reserve battery press *3370# on your cell it will restart automatically and it will shows 50% increase in the battery. When you recharge your cell next time this reserve battery will get charged too.