Currently, batteries used in cars are divided into two types.
The batteries made from mixed of lead-antimony, suitable for general use. They need to take care of and fill the distilled water that lost from applications. The battery will discharge all the time. You need to keep checking the water regularly. If not using the car for a long time, should start the car occasionally to stimulate batteries to have electric current flow.
2. Maintenance Free
Use mixed of lead and calcium, both positive and negative plates in the frame, to make lifetime durable than conventional batteries up to 25%. No need to add distilled water over a lifetime. Even more expensive, but it does not have to check frequently and without the hassle because it has a photocell indicator of power and distilled water.