Rust and corrosion build up on the terminals of a battery. This is largely due to the acid inside the battery and the charge it generates as a result of the chemical reaction in the cells. This rust and corrosion, however, are bad for terminal conductivity. Periodically, you should check the terminals of your battery and clean them of any rust so that you don't have problems starting your vehicle.
Remove the battery cables by loosening the nut on the cable clamp running to the negative battery terminal, then sliding the cable off the terminal. Do the same for the positive terminal.
Sprinkle a liberal amount of baking soda on the battery terminals and on the cable clamps.
Clean the inside of the clamps with a wire brush. Remove any rust that has built up on the inside of the clamp.
Scrub the terminals, one at a time, with a wire brush to remove all the rust and corrosion on the terminals. Since most batteries are acid-based, the baking soda will neutralize the acid (because its a basic material in terms of pH) so that you can safety and effectively clean the terminals.
Clean and wipe down all contact areas on the terminals and the cable clamps.
Put the cable clamps back onto the battery, connecting the power cable first and the ground cable last.
