A couple of weeks ago, I gave you a tip on how to remove whitish battery corrosion. Today, I want to help you remove the black or grey battery corrosion that can often prevent a rechargeable item from working and charging properly. The most common case of this in my house is in our phones- cell and cordless- so that's what I will refer to.
Open the battery case and remove the battery. There should be at least two contact points where raised portions on the phone meet the battery. These are often small square places where the metal on the battery touches the metal on the phone. A small area of grey or black will often form on these points over time. Using a clean pencil eraser, gently rub the grey spots until they disappear. Repeat this on the battery itself. Replace the battery and cover.
If you have a phone that sits on a base to charge, you will want to clean those contact points, both on the phone and the base, with a clean eraser.
Repeating these steps regularly, such as every month, can help your devices perform better and give them a longer life.