Battery Advantages, Facts & Information
The electrical battery, first named by Ben Franklin, is a combination of two or more electrochemical cells used to convert stored chemical energy into electrical energy. Since the invention of the first voltaic pile in 1800, the battery has become a common power source for many household and industrial applications. This page contains definitions and advantages of battery technology used in ETI Products.
ETI offers a wide range of Battery Module technologies and power ratings. Selection between:
Lead Acid Battery Technologies
Lead-acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. Despite having a low energy-to-weight ratio (next to the nickel-iron battery) and a correspondingly low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power-to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
Lead Acid (VRLA)
A VRLA battery (valve-regulated lead-acid battery) is the designation for low-maintenance lead-acid rechargeable batteries. Because of their construction, VRLA batteries do not require regular addition of water to the cells. VRLA batteries are commonly further classified as:
- Absorbed glass mat battery
- Gel battery (gel cell)
These batteries are often colloquially called sealed lead-acid batteries, but they always include a safety pressure relief valve. As opposed to vented (also called flooded) batteries, a VRLA cannot spill its electrolyte if it is inverted. Because VRLA batteries use much less electrolyte (battery acid) than traditional lead-acid batteries, they are also occasionally referred to as an "acid-starved" design.
Flooded Lead Acid (FLA)
Wet or flooded (FLA) batteries require periodic topping up with electrolyte. This is the traditional technology for both starter and leisure batteries having been used for decades. Readily available worldwide for various leisure applications. When used in modern environments these batteries will normally only give you 70-80% of their rated capacity.
Nickel Battery Technologies
Nickel based batteries are available in various battery chemistries. Each battery system offers unique advantages but none provide a fully satisfactory solution. With the increased selection of battery chemistries available today, more informed choices can be made to address specific battery needs:
Nickel Cadmium (NiCad)
The nickel-cadmium battery (commonly abbreviated NiCd or NiCad) is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes. The abbreviation NiCad is a registered trademark of SAFT Corporation, although this brand name is commonly used to describe all nickel-cadmium batteries. The abbreviation NiCd is derived from the chemical symbols of nickel (Ni) and cadmium (Cd). There are two types of NiCd batteries: sealed and vented.
A nickel hydrogen battery (NiH2 or Ni-H2) is a rechargeable electrochemical power source based on nickel and hydrogen.The difference with a nickel-metal hydride battery is the use of hydrogen in a pressurized cell of up to 1200 psi (82.7 bar).
NiH2 rechargeable batteries possess good electrical properties which make them attractive for the energy storage of electrical energy in satellitesand space probes. For example, the ISS, Mars Odysseyand the Mars Global Surveyor are equipped with nickel-hydrogen batteries. The Hubble Space Telescope, when its original batteries were changed in May 2009 more than 19 years after launch, led with the highest number of charge/discharge cycles of any NiH2 battery in low earth orbit.
The nickel-iron battery (NiFe battery) is a storage battery having a nickel(III) oxide-hydroxide cathode and an iron anode, with an electrolyte of potassium hydroxide. Active materials are held in nickel-plated steel tubes or perforated pockets. It is a very robust battery which is tolerant of abuse, (overchargeing, overdischargeing, or short-circuiting) 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 more than 20 years. Due to low specific energy, poor charge retention, and its high cost of manufacture, other types of rechargeable batteries have displaced the nickel-iron battery in most applications. They are currently gaining popularity for solar voltaic backup applications where daily charging makes them an appropriate technology.
A Nickel-Metal Hydride cell, abbreviated NiMH, is a type of secondary electrochemical cell similar to nickel hydrogen cell. The NiMH battery uses a hydrogen-absorbing alloy for the negative electrode instead of cadmium. As in NiCd cells, the positive electrode is nickel oxyhydroxide (NiOOH). A NiMH cell can have two to three times the capacity of an equivalent size nickel-cadmium battery. However, compared to the lithium-ion cell, the volumetric energy density is lower and self-discharge is higher. (Compare: low self-discharge NiMH battery)
Common AA cells (penlight-size) NiMH batteries have nominal charge capacities (C) ranging from 1100 mAh to 2900 mAh at 1.2 V, usually measured at a discharge rate of 0.2×C per hour. Useful discharge capacity is a decreasing function of the discharge rate, but up to a rate of around 1×C (full discharge in one hour) it does not differ significantly from the nominal capacity.
The specific energy density for NiMH material is approximately 70 W•h/kg (250 kJ/kg), with a volumetric energy density of about 300 W•h/L (360 MJ/m³).