Vinegar is a good electrical contact cleaner.
Vinegar's mild acidity helps to dissolve corrosion, on electric contacts and electrical connections including battery terminals.
vinegar can also work much better as an electrical contact cleaner and battery terminal cleaner when it's also combined with baking soda and salt or baking soda with the vinegar.
You can also use baking soda and some water to clean battery terminals and battery connections as well as other electrical connections.
To use vinegar and baking soda to clean electrical contacts and electrical connections or battery terminals.
Start by soaking the corroded connections or contacts in some vinegar or mix some baking soda with some water and pour it over the contacts or electrical connections and then pour some vinegar over the baking soda and allow it to fizz and react.
Then use a brush to scrub away the corrosion and then use water to rinse away the baking soda, vinegar and corrosion.
Just be sure that the electrical connections are disconnected from power, especially if it's 110 volts or higher.
For battery connections you can safely leave the connections connected to power.
However vinegar should not be used to clean screens or electronics as it can damage them but on electrical connections and contacts vinegar is okay to use.
You can also use rubbing alcohol or specialized contact cleaners for cleaning electrical connections and electrical contacts.