What Are Battery Terminal Posts Made Of?by Jin Machina
Much like the plates inside of your car's battery, its terminals are made of lead. Lead is resistant to corrosion, and the terminals are quite simple to clean using baking soda and water.
Along with the typical top-side terminal posts that are peg-like in appearance, there are other types of lead terminals widely found on car batteries. These include side terminals -- holes where the cable connections screw on -- and the L-terminals that sit on top of the battery case and use bolts to secure the cables.
If you should need to ever replace the terminal posts, you should keep in mind to always use lead posts. You may have the option to purchase steel terminal posts. The steel would actually provide less conductivity between the battery and the car's cables or even a charger's clamps. The steel posts may also cause a battery tester to misdiagnose and say that the battery is low on charge.
Be mindful that lead is highly malleable. When clamping the battery cables on, be sure that it isn't so tight that it is grinding and chewing pieces of lead off of the terminals.