A battery is an electro-chemical device that stores an electrical charge and supplies a direct current (DC). The following is a short list of the most common electrical battery types and their applications.
Lead-acid battery
Invented in 1859 by French physicist Gaston Planté, are the most commonly used rechargeable batteries today.
They also represent the oldest design with one of the worst energy-to-weight ratios, although the power-to-weight
ratio can be quite good. Also, the energy-to-volume ratio is good compared to other types of batteries. They are
cheap and can supply high surge current needed in starter motors. Every reasonably modern car uses a lead-acid
battery for this purpose.
| PRO | CON |
| common automobile battery | not suitable for fast charging |
| robust, tolerant to abuse | typical coulombic charge efficiency only 70% but can be as high as 85% to 90% for special designs |
| tolerant to overcharging | danger of overheating during charging |
| wide range of sizes and capacities available | very heavy and bulky |
| the world's most recycled product | typical cycle life 300 to 500 cycles |
| indefinite shelf life if stored without electrolyte | must be stored in a charged state once the electrolyte has been introduced to avoid deterioration of the active chemicals |
Battery of choice for 99 % of solar and back-up power systems.
NiCad (Nickel Cadmium)
Is a type of battery commonly used in portable computers, camcorders, portable drills, and other small battery-powered
devices, having an effective and even power discharge. Although Nickel-Metal Hydride and Lithium Ion batteries are
becoming more popular in mobile computers, Ni-Cd batteries are still the most widely sold.
| PRO | CON |
| very expensive | low efficiency |
| has long life in “chronological terms” but not in “cycle” terms | the use of Cadmium in consumer products is now deprecated on environmental grounds |
| high rate charge and discharge rate possible | NiCad batteries are also prone to damage by overcharging |
| wide temperature range (Up to 70°C) | efficiency: 65 % |
| rapid charge typically 2 hours, but can be as low as 10 to 15 minutes | a major drawback of this technology is its susceptibility to memory effect |
| the coulombic efficiency of nickel cadmium is over 80% for a fast charge but can drop to below 50% for slow charging | low cell voltage of 1.2 Volts compared with primary alkaline cells 1.5 Volts and only quarter of the capacity of the alkaline cells |
Not recommended for most solar and back-up power systems.
NiFe (Nickel Iron)
This rechargeable battery was introduced in 1900 by Thomas Edison. It is a very robust battery which
is tolerant of abuse and can have very long life even if so treated. It is often used in backup situations where it can be
continuously charged and can last for 20 years. Also called Nickel Alkaline of NiFe batteries. The open circuit voltage of
these cells is 1.4V, and the discharge voltage is about 1.2V.
| PRO | CON |
| withstands overcharge and over discharge | high self discharge rate |
| accepts high depth of discharge - deep cycling | the cells take a charge slowly, and give it up slowly |
| lifetime of 30 years possible | very heavy and bulky |
| can remain discharged for long periods without damage | low energy density |
Poor choice for nearly all solar applications.