Selecting the right Rugged PDA depends for some on how long the battery will last, but is size everything in the world of batteries these days…..The answer is definitely not.
The good old days of Nickel Cadmium (Not quite!)
In the old days there was Nickel Cadmium and the way people look after their batteries still goes back to how these behaved. Battery Memory was a problem, remember having to discharge fully and recharge all the way back up again and they lost power quickly? These batteries for many years were the main stalwart for mobile devices but you hardly see them any more. in fact the technology has been deemed by Europe as harmful to the environment so they are in fact banned.
Step in Lithium Based battery tech
Along came Lithium and in the Rugged PDA world, Lithium ION is still the most commonly adopted battery technology. Lithium ION has roughly twice the energy density of Nickel Cadmium but with similar discharge characteristics making them ideal for mobile devices and one cell tends to emit about 3.7V which is why all our Rugged Handhelds either run at 3.7V or 7.4. Along with this Li-ION make for a lower maintenance battery, they do not suffer from memory issues and they also do not require the charge cycle maintenance that old batteries required. They also hold their charge for longer when not in use. The downsides of Li-ION are that they can “pop” and require protection circuitry to keep them safe and they are also subject more to aging if not in use so it is far more common to have to replace Li-ION batteries after a couple of years or sooner in some cases. They’re also expensive to make.
So Big is better? Not quite…
All good I hear you say. So the battle for Milli Amp Hours (mAh) continued which is a measure of the capacity of the battery. 3600mAh for instance is roughly the average size that a rugged PDA battery has and to put that into comparison smartphones still to this day tend to have no more than 1500 or 1600 mAh.
So the old proverb in the rugged PDA market was that the larger device, the larger the battery it would have. Yes some PDA’s use the battery better but when we’ve tested them here the firmware of devices does little to help if users are wasting energy through incorrect power management themselves by leaving screens on or too bright, using software that engages with 3G and GPS chips poorly etc.
Step in the Lithium Polymer Battery
an Li-POL battery is essentially just a Li-ION battery at heart except for its density is much higher. It achieves this by storing it’s electrolyte in a polymer based solid rather than in a liquid solvent. In fact its malleable so can be shaped and this allows for the battery to be shaped more easily and fabricated more inexpensively. Li-POL are currently transforming many markets and you only have to step in to B&Q and see how many power tools are now using the technology. Those Lithium powered batteries in Bosch and Black and Decker tools are in fact Li-POL. The iPad and iPhone would be about twice as think if they couldn’t use Li-POL technology that allows for the battery to be shaped and to be long and flat. In the rugged PDA market we’re also seeing them appear in Rugged PDA’s like the Dotel H300 and they’re good.
I think that smaller Rugged Handhelds that do not have to be designed around a huge battery will drive some innovation in our market. Not only will PDA’s become slimmer and do more but they will start to be seen in better more ergonomic designs too, all driven by the use of Li-POL battery technology!
The Rugged and Mobile blog.