Power Battery Self Charging D-Cell 

Power Battery is a local (Bellevue) company that came up with a terrific idea - make a "D" size rechargeable battery that has a built in charger. It took them years to do it, but they finally did it and got the product to market. The picture to the left is a brief product description from Popular Science magazine some time ago. A pair of these batteries sells for about $12 retail and can be charged over 500 times.

Inside the battery has a "sub-C" Ni-Cad cell and a small circuit board the size of a stick of gum. This circuit converts the 110 VAC from the wall into DC to charge the cell. To use it, you just press the two "tabs" as the base of the battery and pull out the top. Then flip up the prongs and slide the top back down and plug it into a wall socket for about 10 hours. No charger needed!

When Power Battery came to Teague when we started the project, they had made a few thousand cells, but they were having some manufacturing problems. Tom Clary, a Seattle area engineering consultant, did the original design. We helped redesign some of the parts and resolve the manufacturing issues so they could go on to make about 100,000 of these cells and get them to market. We also performed some testing, some liaison with the molding and assembly vendor (they are assembled in Mexico) and helped to get both products through UL safety testing.

This image is a screen snapshot of the "host" cell from Pro/Engineer. It shows how the flip top parts come out of the main battery. On the big version of the image, the white "slab" is the internal charger circuit board.

We also did some minor redesign to incorporate some features for a second "satellite" battery that could clip onto the main "host" battery. The satellite cell did not have a charger circuit, but rather clipped onto the host cell and was charged in tandem.

This satellite cell (show on the left) was only about 75% designed when Teague got involved. We redesigned the internal safety switch and contacts and developed the complete documentation packages so it could go into production. When you look at this, remember the entire cell is only the size of a "D" battery!

Power Battery is struggling today. The product was well received, but it cost too much to make. The company ran low on money and could not get any other size batteries into production although they had working prototypes of a "C" cell that was very nice. It was a less complicated design than the D cell and probably would have sold extremely well as "C" cells are much more popular than "D" cells. If you find some of these at your local store, snap them up as they are a "limited edition" item in addition to being a nifty product.


Last updated: November 09, 1996