What is the difference between a normal lead-acid car battery and a deep cycle battery?

People who have recreational vehicles (RVs) and boats are familiar with deep cycle batteries. These batteries are also common in golf carts and large solar power systems (the sun produces power during the day and the batteries store some of the power for use at night). If you have read the article How Emergency Power Systems Work, then you also know that an alternative to gasoline-powered generators is an inverter powered by one or more deep cycle batteries. Both car batteries and deep cycle batteries are lead-acid batteries that use exactly the same chemistry for their operation (see How Batteries Work for more information). The difference is in the way that the batteries optimize their design: • A car's battery is designed to provide a very large amount of current for a short period of time. This surge of current is needed to turn the engine over dur ... more