Soft drink refreshing answer for common battery problems
Dead battery? Starter not cranking? Battery charging problem? Relax.
If you are away from the shop, disconnect the battery cables, pop the top on a Coke and take a long pull.
After the refreshing drink, pour the rest over the battery terminals and cable ends.
Wait until the foaming has stopped before wiping the excess soda from the battery and cables and rinse with a splash of water.
The phosphoric acid in soda is just corrosive enough to clean the crud from the posts and terminal ends that could be causing the bad connection.
If you happen to have a jar of Vaseline sitting around, smear a dab over each battery post after connecting the cables. This significantly slows corrosion around terminal and battery cable ends.
Of course, the best way to prevent this in the first place is to check/clean the posts and terminals every six months using baking soda/water mixture or a normal battery cleaner and wire brush.