A deep-cycle battery is designed for higher-than-average demands of power, in which the system is repeatedly charged and discharged. There are three man types of deep-cycle batteries: AGM, gel and flooded. These are used mainly on marine vessels and solar power systems.
A car battery has a much lower RC, or reserve capacity, but higher cold-cranking amps than a deep-cycle battery. According to Green Living Tips.com, the advantage of deep-cycle batteries is their steady, low-level power output, while car batteries can only provide higher levels of energy in short bursts.
One common type of deep-cycle battery is the AGM, or Absorbed Glass Mat battery. This battery features a plate of boron-silicate glass that separates the lead plates for additional safety and higher power output levels.
Gel batteries transform the internal battery acids into a jelly, which becomes spill-resistant and ideal for daily usage at high temperatures.
Of the three major deep-cycle battery types, the flooded lead battery is the most like a conventional car battery. It has slightly thicker lead plates but many of the same problems as car batteries, like explosive gas and electrolyte dissipation.