A deep-cycle lead-acid battery (DCLA battery) is designed to be regularly deeply discharged using most of its capacity. In contrast, starter batteries (e.g. most automotive batteries) are designed to deliver short, high current burst for cranking the engine, and to be frequently discharged of only a very small part of their capacity. While a DCLA battery can be used as a starting battery, the lower "cranking amps" imply that an over-sized battery may need to be used.
The structural difference between DCLA batteries and cranking batteries resides in the lead battery plates. DCLA battery plates have thicker active plates, with higher-density active paste material, and thicker separators. Alloys used for the plates in a DCLA battery may contain more antimony than for starting batteries.[1] The thicker battery plates resist corrosion through extended charge and discharge cycles.
Flooded batteries will decompose some water from the electrolyte during charging, and so regular maintenance of flooded batteries requires inspection of electrolyte level and addition of water. Major modes of failure of DCLA batteries are loss of the active material due to shedding of the plates, and corrosion of the internal grid that supports active material. The capacity of a DCLA battery is usually limited by electrolyte capacity and not by the plate mass, to improve life expectancy.[1]A DCLA battery is designed to discharge between 50% and 80% depending on the manufacturer and construction of the battery. Although these batteries can be cycled down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about 50% discharge,[2] as there is a direct correlation between depth of discharge on your battery and the number of charge and discharge cycles it can perform[3]
DCLA batteries are useful for renewable energy storage. Why is storage necessary? The answer is that solar photovoltaic (PV) and wind power are superb as green energy sources, but the major problem with them (when compared to conventional power generation) is that they are non-dispatchable. That is to say that the sun wont always be shining on a given PV panel and the wind won't always be turning a given wind turbine. Consequently, without some way to store the electricity produced, off-grid users will have no power when there is no sunlight or no wind. DCLA batteries are a very popular way form of energy storage for such users. This is primarily because DCLA batteries' price per kilowatt-hour of storage is low, as compared to alternative battery types such as lithium-ion and nickel-metal hydride.
As an additional introduction to DCLA batteries and how they different from standard (automotive) lead-acid batteries, look at this excellent primer at HowStuffWorks.com.
Different users of off-grid PV or wind power generatoring setups will require different levels of battery backup, based on individual needs. The following steps outline how one may go about calculating how much battery backup they require:
| Temperature (°F) | Factor |
|---|---|
| 80 (or more) | 1.00 |
| 70 | 1.04 |
| 60 | 1.11 |
| 50 | 1.19 |
| 40 | 1.30 |
| 30 | 1.40 |
| 20 | 1.59 |
The minimum Amp-hour capacity is the value that is most important when choosing the actual battery units. Once the required Amp-hour capacity is determined, stores or online companies, such as this one, can then provide the batteries.
Many people have concerns about the health impacts of using lead. These issues brought about the end of leaded fuel, but have not yet stopped lead-acid based batteries from being widespreadly used.
According to a 2003 report entitled, "Getting the Lead Out," by Environmental Defense and the Ecology Center of Ann Arbor, Mich., the batteries of vehicles on the road contained an estimated 2,600,000 metric tons of lead. Lead is extremely toxic. Long-term exposure to even tiny amounts of lead can cause brain and kidney damage, hearing impairment, and learning problems in children.[5] The auto industry uses over 1,000,000 metric tons every year, with 90% going to conventional lead-acid vehicle batteries. While lead recycling is a well-established industry, more than 40,000 metric tons ends up in landfills every year. According to the federal Toxic Release Inventory, another 70,000 metric tons are released in the lead mining and manufacturing process.[6]
Attempts are being made to develop alternatives (particularly for automotive use) because of concerns about the environmental consequences of improper disposal and of lead smelting operations, among other reasons. Alternatives are unlikely to displace them for applications such as engine starting or backup power systems, since the batteries are low-cost, although heavy.
It seems that, at least for the foreseeable future (and primarily because of cost), lead-acid batteries will continue to be the primary method of electrical energy storage in off-grid PV and wind projects.
The "from cradle to grave" approach to observing a battery's life cycle yields the following stages:[7]
Lead–acid battery recycling is one of the most successful recycling programs in the world. In the United States 97% of all battery lead was recycled between 1997 and 2001.[8] An effective pollution control system is a necessity to prevent lead emission. Continuous improvement in battery recycling plants and furnace designs is required to keep pace with emission standards for lead smelters.
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|---|---|
| Organizations | CMAS801 |
| Cite as | Abraham (2011–2025). "Deep-cycle lead-acid batteries for renewable energy storage". Appropedia. Retrieved October 3, 2026. |