Regular car batteries are designed to provide a brief but violent burst of power to start the vehicle's engine. However, sealed deep-cycle batteries have thicker plates and denser active materials to withstand repeated charge and discharge cycles.

    Sealed deep cycle batteries are available in two capacity ranges: 6 volts and 12 volts. A flooded lead-acid battery is a type of deep-cycle battery, sometimes called a lead-acid, FLA, or wet battery, that consists of a lead plate or grid with a liquid electrolyte, usually concentrated sulfuric acid, in a container.

    As the cheapest and oldest battery technology, it has been popular with practitioners of budget-conscious and off-grid living. Considering the ratio of the battery's weight to the energy it provides, the FLA is quite heavy. As a result, the popularity of this type of battery is waning.

    Advantages and disadvantages of flooded lead-acid batteries

    Its advantages are as follows:

1. The cheapest
2. Reliable
3. Low internal resistance
4. Can provide very high current
5. Tolerate Abuse and Excessive Charges
6. Indefinite shelf life if stored without electrolytes
7. Can maintain trickle or float charge for a long time
8. Available through many suppliers worldwide
9. The most recycled product in the world

    Shortcoming:

1. Very bulky
2. Typical usable capacity is 30% to 50%
3. The charging efficiency is 70% to 85%
4. High self-discharge, 5% per month
5. It may overheat when charging
6. Toxic gas is generated when charging
7. Regular maintenance is required to replenish the electrolyte
8. Low cycle life - about 300 to 500 cycles
9. Must be fully charged to avoid damage
10. Must be kept upright to prevent electrolyte spillage
11. Sensitive to freezing (shell burst, electrolyte overflow)

    Changshu Wanlong Power Technology R&D Co., Ltd. is a storage battery manufacturer from China. The company sells sealed gel batteries all year round.