Battery trickle chargers come in a variety of types and sizes, including those made for motorcycles, cars and boats. Its purpose is to help your battery maintain its charge when the battery is unused for long periods. Purchase a trickle charger at an automotive supply store, a retail store such as Sears or Wal-Mart, or online at various sites including J.C. Whitney. If you are unsure which charger you need, ask a knowledgeable salesperson to help you.
A fully discharged automotive battery may take up to 20 hours for full charging. The length of time is dependent upon the RC rating (reserve capacity). A battery with an RC of 60 and 2 amps could take 20 hours to charge, while a battery with an RC rating of 60 with 30 amps may take only one hour to fully charge.