On a recent trip to visit my daughter, we found the electronic deadbolt to her apartment was – well, dead. Fortunately a roommate was inside and able to open the door, and afterwards we replaced the four AA batteries in the unit.
I’m imagining that many of you are fresh off similar experiences with the electronic devices you got over the holidays. For instance, I understand the Nintendo Wii Remote eats two AA batteries every 30 hours with the MEMS accelerometer and pointer device on.
I’m thinking of rewriting that scene in Blazing Saddles for a battery commercial. Instead of a plea for dimes to feed the absurd toll booth in the middle of nowhere, Mr. Taggart (in that Slim Pickens drawl) utters: “Somebody’s gotta go back and get a whole mess of AA batteries.”
Charge it on my USB
The primary AA battery and other batteries as we know them are not going away soon, but other ideas are hitting the market.
A new twist on the secondary AA battery is the USBCELL by Moixa Energy Ltd. (Figure 1). These are standard AA size rechargeable NiMH cells (1.2 V, with a 1,300 mAh capacity) but with a handy feature – when you flip the end cap, a USB connector is revealed. Plug the battery into any USB port, and the battery recharges enough for temporary use in a few minutes and completely in a few hours.
Figure 1
Two pairs of USBCELLs might be worth the price for Wii addicts out there – one pair in use, one pair charging in the Wii console. These would also be handy in an office environment for things like the DLP projector remote, laser pointer, or other device that seems to be dead just when most needed. A couple minutes with the USBCELLs in a USB port, and that online match or meeting can proceed.
Better chemistry, longer power
Rechargeable NiMH is today’s technology, but fuel cells are in the foreseeable future as a portable power solution. Last year, we noted UltraCell launched its XX25 reformed methanol fuel cell for laptop systems. Inventors are continuing to push the envelope seeking denser, longer-lasting solutions for portable electronics power.
Chemists at Arizona State University’s (ASU’s) Biodesign Institute have created a tiny hydrogen-gas generator using an improved solution containing borohydride. Unlike other fuel sources, borohydride works at room temperature to liberate hydrogen.
“We’re trying to maximize the usable hydrogen storage capacity of borohydride in order to make a fuel cell power source last longer,” says study leader Dr. Don Gervasio, an associate research professor within the institute’s Center for Applied NanoBioscience. “That could lead to the most powerful power source ever produced for portable electronics.”
Borohydride isn’t new for fuel cells, but using novel chemical additives Gervasio’s team is working to increase hydrogen capacity of their solution two to three times that of simple aqueous sodium borohydride solutions, while preventing the solution from solidifying.
The ASU prototype fuel cell system houses the improved boro-hydride solution in a tiny gas generator containing a ruthenium metal catalyst. In the presence of the catalyst, the borohydride solution reacts to form hydrogen gas. The hydrogen moves across a special gas/liquid separating membrane to the fuel cell component, where it combines with oxygen to generate electricity. Because the hydrogen generated is consumed immediately and produces only a nontoxic watery by-product, the fuel cell is safe.
Although the fuel cell itself is reusable and doesn’t need recharging, the borohydride fuel eventually is depleted and replacing borohydride cartridges is required. The fuel cell generates some heat, but researchers find it generally doesn’t get any higher than body temperature.
While the prototype fuel cell is the size of a shoebox, Gervasio says this borohydride technology can be developed into a compact fuel cell package and commercialized within a few years, powering portable electronic devices three to five times longer than conventional batteries of the same size and weight.
Creative portable power?
I’d say I’ve had enough; it’s time for some better portable power ideas like these. Here’s a question for designers: What do you see as creative portable power solutions for the devices you’re designing today? As always, e-mail your thoughts and ideas to ddingee@opensystems-publishing.com – before those AA batteries we all depend on give out again.
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