Battery

A battery is an electrochemical cell (or enclosed and protected material) that can be charged electrically to provide a static potential for power or released electrical charge when needed.

There are a lot of different kinds of batteries, but they all function based on the same underlying concept.  They are able to store electrical energy in the form of chemical energy, and convert that energy into electricity,You cannot catch and store electricity, but you can store electrical energy in the chemicals inside a battery.”  

There are three main components of a battery: two terminals made of different chemicals (typically metals), the anode and the cathode; and the electrolyte, which separates these terminals. The electrolyte is a chemical medium that allows the flow of electrical charge between the cathode and anode. When a device is connected to a battery — a light bulb or an electric circuit — chemical reactions occur on the electrodes that create a flow of electrical energy to the device.  

More specifically: during a discharge of electricity, the chemical on the anode releases electrons to the negative terminal and ions in the electrolyte through what’s called an oxidation reaction. Meanwhile, at the positive terminal, the cathode accepts electrons, completing the circuit for the flow of electrons. The electrolyte is there to put the different chemicals of the anode and cathode into contact with one another, in a way that the chemical potential can equilibrate from one terminal to the other, converting stored chemical energy into useful electrical energy. These two reactions happen simultaneously.

If the battery is disposable, it will produce electricity until it runs out of reactants (same chemical potential on both electrodes). These batteries only work in one direction, transforming chemical energy to electrical energy. But in other types of batteries, the reaction can be reversed. Rechargeable batteries (like the kind in your cellphone or in your car) are designed so that electrical energy from an outside source  can be applied to the chemical system, and reverse its operation, restoring the battery’s charge.  

Types of Batteries

There are three main types of batteries that are commonly used in renewable energy systems, each with their own advantages and disadvantages.  Flooded or “wet” batteries are the most cost efficient and the most widely used batteries in photovoltaic applications.  They require regular maintenance and need to be used in a vented location, and are extremely well suited for renewable energy applications.  Sealed batteries come in two varieties, the gel cell and Absorbed Glass Mat (AGM) type.  The gel cell uses a silica additive in its electrolyte solution that causes it to stiffen or gel, eliminating some of the issues with venting and spillage.  The Absorbed Glass Mat construction method suspends the electrolyte in close proximity with the plate’s active material.  These batteries are sealed, requiring virtually no maintenance.  They are more suitable for remote applications where regular maintenance is difficult, or enclosed locations where venting is an issue. These types of batteries as available at Real Summit Network office are listed below.

1. Deep Cycle Batteries

Deep cycle batteries are designed with thicker lead plates, which have less overall surface area than their thinner SLI counterpart.  Because of the reduced availability of surface area for chemical reactions, deep cycle batteries produce less current than an SLI type battery, yet they produce that current for longer periods of time.  Deep cycle batteries can be discharged up to 80 percent DOD without damage depending on the model.  In order to increase battery life, manufacturers recommend discharging deep-cycle batteries only down to 50 percent in order to increase battery life.

Deep Cycle Batteries are the key component in various types of renewable energy systems that require the storage of electricity.  It is a critical battery heavily relied upon by the system as a whole.

Deep cycle Battery Lifespan

Most of the loss incurred in charging and discharging batteries is due to internal resistance, which is eventually wasted as heat.  Efficiency ratios are relatively high considering that most lead acid batteries are 85 to 95 percent efficient at storing the energy they receive.  Deep cycle batteries used in renewable energy applications are designed to provide many years of reliable performance with proper care and maintenance.  Proper maintenance and usage play a major role in battery lifespan. Toiling over your battery bank daily with complex gadgets and a gallon of distilled water, however, is not necessary.  The most common causes of premature battery failure include loss of electrolyte due to heat or overcharging, undercharging, excessive vibration, freezing or extremely high temperatures, and using tap water among other factors.

Amp-Hour Rating & Capacity

All deep cycle batteries are classified and rated in amp-hours.  Amp-hours is the term used to describe a standardized rate of discharge measuring current relative to time.  It is calculated by multiplying amps and hours.  The generally accepted rating time period for most manufacturers is 20 hours.  This means that the battery will provide the rated amperage for about 20 hours until it is down to 10.5 volts or completely dead.  Some battery manufacturers will use 100 hours as the standard to make them look better, yet it can be useful in long-term backup calculations.

1. Flooded Lead Acid

Flooded Lead Acid batteries are the most commonly used batteries, and have the longest track record in solar electric systems.  They usually have the longest life and the lowest cost per amp-hour of any of the other choices.  The downside is that they do require regular maintenance in the form of watering, equalizing charges and keeping the terminals clean.  These cells are often referred to as “wet” cells, and they come in two varieties: the serviceable, and the maintenance-free type (which means they are designed to die as soon as the warranty runs out). The serviceable wet cells come with removable caps, and are the smarter choice, as they allow you to check their status with a hydrometer.