Corroded battery terminals usually cause more problems than just poor starting of your car. There are of course, extreme cases of corrosion, but even the minor ones can still reduce alternator output by a huge percent stressing the charging system and causing other early battery failures. The extra resistance leads to slower cranking, premature starter failure and overheated starter motor windings. It is fortunately possible to prevent the issues by stopping the corrosion.
One of the best ways of keeping the battery working for longer is by trying every means possible to stop battery terminal corrosion. Acid leaks from the battery often lead to less damages to the terminals and through prevention and proper cleaning you can be in a position to stop the effects of corrosion.
To stop corrosion on the terminals, you should try using petroleum jelly on them. This can be done by removing the connector cables on the battery and coating posts liberally with the jelly before reattaching the cables. The coating allows electrical current to flow freely and at the same time protects your battery from potential corrosion.
Still on protection you can consider painting the posts using silicone spray. Most auto stores will have the spray and it works in the same way as the jelly. Simply remove the connections from the battery and spray the paint onto the posts, then allow proper drying before reconnecting your cables to keep the battery corrosion free. It may also be a good idea to consider getting cable terminal covers or protective covers for battery negative and positive to keep your battery in top condition and functioning as it should.
In case you are not able to protect the terminals from corrosion and you are already dealing with a case, cleaning can offer the much needed relief from the effects of corrosion. To clean the terminal, you would need to start by disconnecting cable hookups and removing the battery. Using a wire brush and a mix of baking soda and warm water, you can then thoroughly clean out the area. You should allow it to dry properly before replacing your battery. It is a simple cleaning method that helps in fighting corrosion impacts on your charging system and at the same time also prevents further corrosion. You can also clean easily using a spray cleaner and applying acid neutralizing felt pads before finishing the cleaning with an anti-corrosive spray on each terminal.
In some case, you may find that you are dealing with extreme cases of corrosion on your battery terminals requiring replacement of the terminals. Replacement may be necessitated when both terminals don't seem to clamp tightly or the corrosion has eaten away the metal. Green corrosion on copper cables going into molded lead terminal also means it is time to do a replacement. If you must do a replacement, consider copper compression terminal which offers better connection compared to lead terminals which may be cheaper but end up compromising electrical connections.