How many types of batteries are there?
There are many types of batteries depending upon the usage. For instance there are primary and secondary batteries, wet and non-wet (gel-type) types, conventional and maintenance free, and even wet-charged and dry-charged batteries. Moreover, there are many overlaps between these categories. For instance, a secondary battery can either be wet or gel-type, conventional and maintenance free.

Why do the battery dealers talk in terms of dry-charged and wet-charged battery?
A dry-charged battery is stored on the dealer’s shelf without electrolyte in it. The dealer must put electrolyte in the battery and briefly charge it before installation in the vehicle.

A wet-charged battery is stored on the shelf with electrolyte already in it. It may require charging before dealer installation. Wet-charged batteries that are stored too long without periodic charging may become permanently damaged.

Dry-charged batteries have the advantage of a longer shelf life. Wet-charged batteries are usually ready to go from the dealer’s shelf with little or no charging.

What’s all this hype about MF (Maintenance Free) Battery?
Maintenance free batteries are constructed differently than conventional batteries. They have lead-calcium plates instead of lead-antimony plates. This reduces the amount of electrolyte loss because there is less gas production. These batteries are wet-charged and have a longer shelf life due to a low discharge rate.