Car Chargeable Battery Pack

Black & Decker makes a line of devices with the name “VersaPak.” The batteries for these devices are cylindrical and snap directly into the handles of the tools that use them, with one end of the battery extending beyond the end of the handle for easy removal. They are 24 mm (1 inch) in diameter and 115 mm (4.5 inches) long, and produce 3.6 V. See first link for a photo.

These batteries are very handy because they can be exchanged very quickly, and used interchangeably with any compatible devices you have. Rather than having eight different chargers for eight different tools, you can have one charger and a stable of batteries you can use in all of them.

The dimensions of these batteries got me thinking. They reminded me of the dimensions of another round device that produces 12 V: the standard auto cigarette lighter, now used as a low-power electrical socket by most people. This socket is 20 mm in diameter.

I propose a new rechargeable battery battery, 20 mm in diameter and about 130 mm long, of a similar general nature. The electrical connector end of the design will be designed to allow the battery to be charged by inserting it directly into any auto cigarette lighter socket.

To avoid overcharge by the “dumb” auto socket, some circuitry must be incorporated into the battery. This is not a problem; many laptop batteries already some electronics embedded into the battery itself to help regulate the charging.

Black & Decker appears to have some Patents covering VersaPak (see second link). That may pose a problem with baking this, unless of course you happen to work for them.

VersaPak is a trademark of Black & Decker.