http://www.futureelectronics.com/en/Search.aspx?dsNav=Ntk:PlainTextSearch%7cBatteries%7c3%7c,Ny:True,Nea:True,N:577 . Today we will be talking about power sources, the technologies of how energy is stored and their features and benefits. So why batteries? Batteries store energy well and for a considerable length of time. Primary batteries (non-rechargeable) hold more energy than secondary (rechargeable), and the self-discharge rate is lower. http://youtu.be/0wkWorrhX50