Christmas morning 1979 Santa delivered Bigtrak under the Christmas Tree, unfortunately he forgot the batteries… I was just 1 x 9V and 4x 1.5V D Cells away from Christmas morning heaven!. So, instead I had to make do with an Etch-a-Sketch until Boxing day when Granddad Gadget arrived with his box of batteries from his under stairs cupboard. Growing up in the 1980’s put me right at the start of the portable electronics evolution. I became a self confessed gadget junkie, which left me with a big dent in my pocket money by having to constantly shell out for the multiple batteries required to power gadgets like my Walkman. My worse battery thirsty gadget however was my Boom Box, that I had during my Breakdance phase. This required 8 D Cells that didn’t seem to last long until the tape playing started to slow down before conking out!
Thank goodness those days are gone. However, in today's society, few of us would survive without batteries. There everywhere in our everyday lives, cell phones, remote controls, pacemakers, keyfobs, the list is endless, and although the electronics evolution has reduced the amount of power required to run our modern electronic devices, so that we can get a longer experience between changing or charging, the fundamental problem with batteries remains the same..., they need replacing or recharging regularly!
Perhaps one day we will have the technology to have a battery that never needs recharging, like the Oroborus batteries that feature in one of my favourtite SCI-FI TV series, Red Dwarf. However, in terms of a bit less "science fiction", battery technologies such as those using Nuclear Power or even water are available today. I am also aware of some companies developing wireless power charging ,where your portable electronics devices can be charged wirelessly from the mains or even receive power from another portable device... how cool is that, just as long as it doesn't fry my vital organs in the process!
So if the prospect of having an everlasting battery is way off in the future, then what’s the answer for today?
Companies like Varta and Panasonic are at the forefront of battery technology, but it’s not just about the battery. In terms of electronic design, there are things that we can do to help get more battery life out of our applications. It’s all about lowpower! Modern Microcontrollers are pretty low power, such as the XLP range from Microchip that boast extreme low power. For applications that need to be on all the time, we can do basic things like put them to sleep and wake them up when needed. I also stumbled across an interesting application note from Microchip that shows you how to squeeze as much juice as possible out of a battery before it dies. Often when a battery starts to go flat, it will get to a point where the circuit it’s supplying will think that there’s not enough energy left to power the application and switch off, however, in reality there is generally sufficient energy left to last longer, perhaps as much as 20% longer. One solution is to include a Microchip MCP1640 DC Boost Convertor in your design, you can find the application note here.
Have you got any tips and tricks for saving power when designing battery powered applications? Please share them with us. Or are you a battery guru!, what's the future of battery technology? We'd love to here from you.