J
Jarret W. Buse
Guest
A Battery of Information about Batteries
Many devices in the world today are portable and require a portable power supply or battery. Even desktop systems can use a battery backup system, or Uninterruptable Power Supply (UPS), to help provide a source of power if the main power goes out. Knowing your options for batteries can help you make critical decisions about using batteries.
Batteries are not a new invention. At an archaeology dig in Khujut Rabu, clay pots were found with an iron bar coated in copper. The pots showed evidence of containing vinegar or wine. When replicated, these pots produced a low amount of electricity. The pots were dated to be from 200 B.C.
The first commercially sold battery was in 1898, called the Columbia Dry Cell, produced by the National Battery Company, which is now called the Eveready Battery Company (it sells the Energizer brand battery).
Batteries are called 'cells' and there are two types of cells:
The connection points of the anode and cathode are where the electrons flow out of and into the cell. These connection points are called terminals.
Each cell is encased in either metal or plastic, and inside the casing are the anode, cathode and electrolyte substances. The anode and cathode substances are separated by a separator. The separator is between the two other substances, but is perforated to allow the electrolyte and electrons to flow between. To gather the free electrons and pass to the negative terminal, a collector is used.
Let's look at the three types of rechargeable batteries:
The Nickel Cadmium (NiCad or NiCd) batteries are not used much anymore. The problem is that they hold a small charge and weigh a lot. The cadmium is also a toxic substance and requires special recycling.
Nickel-Metal Hydroxide (MiMH) batteries can hold twice the amount of charge as a NiCad battery in the same weight. The extra charge allows it to last twice as long as the NiCad batteries. The problem with the NiMH batteries is that when you use the battery, you must use it until the charge is gone. Once the charge is depleted, the battery must be fully charged again before use.
Both the NiCd and NiMH batteries have a “memory” issue. The issue is caused by crystallization of the electrolytes and other substances within the cell. Once the substance crystalizes, they cannot be used during the recharge. The result is that the battery cannot fully charge and “remembers” the point of it's most recent full charge. The reverse is also true, that the discharge is also “remembered” and the cell cannot discharge past the last discharge point. Once the crystallization occurs, the battery cannot hold a full charge anymore and will continue to deteriorate.
NOTE: The NiMH batteries are affected less by the “memory” problem than the NiCd batteries.
When using NiCd or NiMH batteries, be sure not to overcharge the battery. To overcharge a battery is to leave it in a charging state even after the charge is completed. Some chargers are “dumb” meaning that they continue to charge the battery even after it is full. A “smart” charger will stop charging when the battery is full and prevent an overcharge. Overcharging can also cause the battery to get the “memory” problem.
The newest and best type of rechargeable battery is the Lithium Ion (Li-Ion) battery. The main advantage is that the Li-Ion battery can hold the same charge as a NiMH battery, but with half the weight. The Li-Ion batteries were originally believed to not have the “memory” effect, but it has been shown that this is not the case.
A comparison of the Li-Ion and the NiMH batteries show the following:
Another factor to consider between the two batteries is the discharge rate. Sitting on a shelf, the NiMH loses about 20% of its charge per month. The Li-Ion battery only loses about 5% per month due to the use of the internal monitoring system.
The internal monitoring system of a Lithium Ion battery is comprised of:
Lithium-Ion batteries last 2-3 years from the manufacturing date. Because of this, you want to check the manufacturer's date when purchasing one. Keep in mind that heat is an enemy to a battery. Li-Ion batteries will degrade if exposed to heat. Something very important about Li-Ion is that if the battery is fully discharged, it cannot be recharged again. Li-ion batteries are more expensive due to the fact that they are “smart” batteries. The extra cost is due to the “computer” within the pack to monitor the cells.
One main thing about the Li-Ion battery is that there is a vent hole. Lithium is extremely volatile and if it becomes overheated, the pressure within the cell becomes too much for the casing. Li-Ion cell casings are metal since they are under pressure to begin with. If the pressure becomes too much, the cell is vented to prevent it from exploding. Once vented, the cell is no longer usable in most cases.
NOTE: Two to three Li-Ion packs out of a million has exploded or caught fire.
The electron movement within a Li-Ion cell can produce around 3.7 volts. Since most packs produce around 10 or more volts, there is more than a single cell within the pack. Because of the number of cells, it is best when a battery pack is first used, it should be charged for numerous hours before the first use. An overcharge should not occur because of the internal monitoring system. The need is to be sure that all the cells are charged evenly. The cells closest to the incoming electron flow during recharge will be charged first and then the next cell and so on until all are full. It is extremely important to have all the cell charges “balanced”.
NOTE: When you get any new device which requires a specific number of hours to be charged, follow the directions. It is best to get the cells charged correctly the first time so you do not lose any of the charge ability.
Many devices in the world today are portable and require a portable power supply or battery. Even desktop systems can use a battery backup system, or Uninterruptable Power Supply (UPS), to help provide a source of power if the main power goes out. Knowing your options for batteries can help you make critical decisions about using batteries.
Batteries are not a new invention. At an archaeology dig in Khujut Rabu, clay pots were found with an iron bar coated in copper. The pots showed evidence of containing vinegar or wine. When replicated, these pots produced a low amount of electricity. The pots were dated to be from 200 B.C.
The first commercially sold battery was in 1898, called the Columbia Dry Cell, produced by the National Battery Company, which is now called the Eveready Battery Company (it sells the Energizer brand battery).
Batteries are called 'cells' and there are two types of cells:
- Primary (non-rechargeable)
- Secondary (Rechargeable)
- Anode (-)
- Cathode (+)
- Electrolyte
The connection points of the anode and cathode are where the electrons flow out of and into the cell. These connection points are called terminals.
Each cell is encased in either metal or plastic, and inside the casing are the anode, cathode and electrolyte substances. The anode and cathode substances are separated by a separator. The separator is between the two other substances, but is perforated to allow the electrolyte and electrons to flow between. To gather the free electrons and pass to the negative terminal, a collector is used.
Let's look at the three types of rechargeable batteries:
- Nickel Cadmium (NiCad, NiCd)
- Nickel-Metal Hydride (NiMH)
- Lithium-ion (Li-Ion)
The Nickel Cadmium (NiCad or NiCd) batteries are not used much anymore. The problem is that they hold a small charge and weigh a lot. The cadmium is also a toxic substance and requires special recycling.
Nickel-Metal Hydroxide (MiMH) batteries can hold twice the amount of charge as a NiCad battery in the same weight. The extra charge allows it to last twice as long as the NiCad batteries. The problem with the NiMH batteries is that when you use the battery, you must use it until the charge is gone. Once the charge is depleted, the battery must be fully charged again before use.
Both the NiCd and NiMH batteries have a “memory” issue. The issue is caused by crystallization of the electrolytes and other substances within the cell. Once the substance crystalizes, they cannot be used during the recharge. The result is that the battery cannot fully charge and “remembers” the point of it's most recent full charge. The reverse is also true, that the discharge is also “remembered” and the cell cannot discharge past the last discharge point. Once the crystallization occurs, the battery cannot hold a full charge anymore and will continue to deteriorate.
NOTE: The NiMH batteries are affected less by the “memory” problem than the NiCd batteries.
When using NiCd or NiMH batteries, be sure not to overcharge the battery. To overcharge a battery is to leave it in a charging state even after the charge is completed. Some chargers are “dumb” meaning that they continue to charge the battery even after it is full. A “smart” charger will stop charging when the battery is full and prevent an overcharge. Overcharging can also cause the battery to get the “memory” problem.
The newest and best type of rechargeable battery is the Lithium Ion (Li-Ion) battery. The main advantage is that the Li-Ion battery can hold the same charge as a NiMH battery, but with half the weight. The Li-Ion batteries were originally believed to not have the “memory” effect, but it has been shown that this is not the case.
A comparison of the Li-Ion and the NiMH batteries show the following:
- NiMH – 100 Watt hours / kilogram
- Li-Ion – 150 Watt hour / kilogram
Another factor to consider between the two batteries is the discharge rate. Sitting on a shelf, the NiMH loses about 20% of its charge per month. The Li-Ion battery only loses about 5% per month due to the use of the internal monitoring system.
The internal monitoring system of a Lithium Ion battery is comprised of:
- Temperature sensors – monitors temperature of cells
- Voltage converters – keep voltage levels safe
- Regulator circuit – keeps current levels safe
- Notebook connector – connection point to allow data and power to pass through to the connected device
- Voltage tap – monitors each cell within the battery
- Battery charge state monitor –a small “computer” to monitor the charging of the cells so the recharge can be full and quick
Lithium-Ion batteries last 2-3 years from the manufacturing date. Because of this, you want to check the manufacturer's date when purchasing one. Keep in mind that heat is an enemy to a battery. Li-Ion batteries will degrade if exposed to heat. Something very important about Li-Ion is that if the battery is fully discharged, it cannot be recharged again. Li-ion batteries are more expensive due to the fact that they are “smart” batteries. The extra cost is due to the “computer” within the pack to monitor the cells.
One main thing about the Li-Ion battery is that there is a vent hole. Lithium is extremely volatile and if it becomes overheated, the pressure within the cell becomes too much for the casing. Li-Ion cell casings are metal since they are under pressure to begin with. If the pressure becomes too much, the cell is vented to prevent it from exploding. Once vented, the cell is no longer usable in most cases.
NOTE: Two to three Li-Ion packs out of a million has exploded or caught fire.
The electron movement within a Li-Ion cell can produce around 3.7 volts. Since most packs produce around 10 or more volts, there is more than a single cell within the pack. Because of the number of cells, it is best when a battery pack is first used, it should be charged for numerous hours before the first use. An overcharge should not occur because of the internal monitoring system. The need is to be sure that all the cells are charged evenly. The cells closest to the incoming electron flow during recharge will be charged first and then the next cell and so on until all are full. It is extremely important to have all the cell charges “balanced”.
NOTE: When you get any new device which requires a specific number of hours to be charged, follow the directions. It is best to get the cells charged correctly the first time so you do not lose any of the charge ability.
