Dirty connectors can degrade your laptop’s battery life. To clean them, first turn your laptop off and unplug it. Make sure to turn it all the way off, not just close the lid or put it in sleep mode. On Windows, this is accomplished by choosing “Shut down” from the Start menu.
After doing that,you have to turn it over and check to see how it says to remove your battery. There is usually a switch that you have to click to the “off” position, then another one that you have to pull back and hold while you’re taking the battery out. If you aren’t sure what to do, consult your laptop’s instruction manual (and if you lost it, you can usually find one for your model of laptop online).
You can wash the gold contacts on your laptop and its battery by using a cotton swab or other gentle cloth, that’s slightly damp with rubbing alcohol. Just make sure to let it dry completely before plugging it back in.