How Do I Know if a Capacitor Is Polarized or Non-Polarized?
- 1). Check the capacitor case. If there is an arrow with "-" symbols, a black arrow or a black stripe running down one side of the capacitor case, the capacitor is polarized. The arrow or black stripe is always printed next to the negative lead. If there is no arrow, proceed to the next step.
- 2). Check the length of the capacitor's wire leads. When both leads are on the bottom of the capacitor and one lead is longer than the other, the capacitor is polarized. The short lead is the negative lead. If the capacitor contains connection lugs instead of wire leads, proceed to the next step.
- 3). Check the top of the capacitor. Some polarized capacitors -- such as car audio capacitors -- contain "+" and "-" markings at the top near the capacitor's electrical terminals.
