Have you got one of those cordless drills sitting around that hardly get used. If it's a 12 Volt version then , with this simple modification you can Jump start your car when you get a Flat battery, or just use it as a portable power pack.
Step 1: Simple Modification
Start by removing the screws that holds the battery pack together and remove the cover.
Find a suitable place for a connector and cut or drill a hole to suit the connector.
Solder a wire to the Positive and Negative of the battery Pack then ,run these wires to the connector.
screw the cover back on and connect the Jumper Leads. You now have a 12 Volt portable Power Pack,
That you can Jump Start your Car with.