If you ever find yourself with a car that won't start because of corroded battery terminals, you can get yourself going again with just a can of Coca-Cola.
I'm from the US south, where we know that Coke is magical stuff, and I've used this trick several times myself over the years without scrubbing the terminals afterwards. Perhaps it's the acidity level, but more likely it's just the foaming action. I have also tried water and it didn't so so well if you didn't also use a brush to scrub the corrosion away. Other soft drinks, or soft drinks that have gone flat, also don't seem to work as well.
If your terminals continue to corrode easily, you should probably get that checked out. It may be time for a new battery or you may be able to protect those terminals against corrosion. But if you're stuck somewhere, a can of Coke may just get you back on the road.
How to Clean Battery Terminals With Coke [HowToDoYourself]