Wind Energy System Batteries
Wind energy systems use a kind of battery called a lead-acid deep cycle battery. This is very different from a conventional car battery (also called a start battery).
You might say a lead acid battery is very heavy duty.
The lead acid deep cycle battery is designed to be very tolerant of ongoing charging and discharging.
A lead-acid deep cycle battery also costs far more than a conventional battery. The battery used in an independent wind energy system will tend to discharge often, depending on wind consistency.
Battery Size System
You need to consider the size of your battery system carefully. If you use small batteries, you run the risk of discharging them too often, and so you will have to replace them. A battery properly sized for your wind energy system and well maintained will last 10 to 15 years-well worth the investment in money and time.
Depth of Discharge
Depth of discharge is a measure of how much energy has been taken from a battery. The lead-acid deep cycle batteries used in small wind energy systems are much more tolerant of discharges, as compared to regular car batteries. A 50% to 80% discharge of your wind energy system battery will be tolerated by a typical lead-acid deep cycle battery. You can discharge the battery thousands of times at this rate.
There are several kinds of deep discharge batteries, of which flooded cell batteries are the most common. These can withstand overcharging, are low cost (compared to others) and built to have a long life. Other kinds also have other features, including the following:
- Sealed flooded cells are maintenance free but can be damaged by overcharging.
- Recombinant flooded cells are more expensive but will not spill acid.
- Gelled electrolyte cells are also expensive and are more versatile in mounting.