1.It is helpful to know the difference between car battery and solar battery. While car and solar batteries are quite different, understanding the distinction between the two can help homeowners understand the details of solar batteries.All batteries have a chemical reaction, which creates an electric current used to power devices. How the electrical current is formed and stored makes much effect on the amount of electricity that the battery can produce. Unlike regular batteries, rechargeable batteries can recharge by reversing the chemical process. By applying electricity to the battery, the chemical reaction in the battery that releases the electrical current reverses, enabling the battery to power something else.While the concept of charging and discharging a battery isn’t new, the application of it in other products, such as cars, is different than solar battery. 2.Different ways of the design that optimize the battery. 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: 2.(1) How does car battery design to work ? A car 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 during starting. Once the engine starts, the alternator provides all the power that the car needs, so a car battery may go through its entire life without ever being drained more than 20 percent of its total capacity. Used in this way, a car battery can last a number of years. To achieve a large amount of current, a car battery uses thin plates in order to increase its surface area. 2.(2)How does deep cycle battery design to work ? A deep cycle battery is designed to provide a steady amount of current over a long period of time. A deep cycle battery can provide a surge when needed, but nothing like the surge a car battery can. A deep cycle battery is also designed to be deeply discharged over and over again (something that would ruin a car battery very quickly). To accomplish this, a deep cycle battery uses thicker plates. 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. 3.The different parameter between car battery and deep cycle battery. A car battery typically has two ratings: （1）CCA (Cold Cranking Amps) – The number of amps that the battery can produce at 32 degrees F (0 degrees C) for 30 seconds （2）RC (Reserve Capacity) – The number of minutes that the battery can deliver 25 amps while keeping its voltage above 10.5 volts Typically, a deep cycle battery will have two or three times the RC of a car battery, but will deliver one-half or three-quarters the CCAs. In addition, a deep cycle battery can withstand several hundred total discharge/recharge cycles, while a car battery is not designed to be totally discharged.