Additions:
Note - there are other batteries available with this same chemistry. They may have slightly different characteristics in terms of maximum current, but are very similar. See new material near the bottom of the page
Other Lithium Iron Rechargeables
RCR123 cells (CR123 Lithium size cells used commonly in high tech flashlights)
Black and Decker Universal Power System∞
Additions:
Additions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells, 10 each from two DeWalt 9360 36V lithium power tool battery packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11.5 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! Not bad for a three pound battery! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts and above 12.5 for almost the entire discharge cycle. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Oliver KB6BA is starting to experiment with these batteries. He is using two of the 6V 4.6AH commercial packs in series for portable HF operations. This allows a non-homebrew solution (just need to solder an adapter plug to series the batteries). More info as it comes to my attention!
A good low cost and safe A123 battery charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total for a 4 cell series pack.) The cells can be charged in parallel, several stacks at once. The FMA charger runs from 12V and charges at up to 4 amps. The RC folks also have chargers for the 6V RC packs. See links below.
Deletions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells, 10 each from two DeWalt 9360 36V lithium power tool battery packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11.5 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! Not bad for a three pound battery! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Oliver KB6BA is starting to experiment with these batteries. He is using two of the 6V 4.6AH commercial packs in series for portable HF operations. More info as it comes to my attention!
A good low cost and safe A123 battery charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total for a 4 cell series pack.) The cells can be charged in parallel, all 5 at once. The FMA charger runs from 12V and charges at up to 4 amps. The RC folks also have chargers for the 6V RC packs. See links below.
Additions:
A123 Battery Safety
A123 Battery Weight Compared
A123 Battery Simple Solar Charging
More A123 Info
Deletions:
Safety
Weight Compared
Simple Solar Charging
More Info
Additions:
From the above link you can see that at 10A the output voltage of a single cell stays above 3V out to almost 2.0AH. This for a single cell rated at 2.3AH. This corresponds to more than 12V output from a 4 cell series pack discharged at over 4C (4 times the amp-hour capacity), which is a heavy discharge. This is excellent performance for 12V type radios that lose performance when powered from voltages below 12V (which is a problem for small gel type lead-acid batteries as they drop below 12.0V long before they are fully discharged at moderate currents).
Deletions:
From the above link you can see that at 10A the output voltage of a single cell stays above 3V out to almost 2.0AH. This for a single cell rated at 2.3AH.
Deletions:
From the A123 site:
"A123 materials are designed to ensure all the Lithium is fully extracted from the cathode when the battery is fully charged. As a result safety issues relating to overcharge are eliminated because there is no Lithium available to plate on the anode in an overcharged state. This is in contrast to conventional Li Ion cells, which only extract half their Lithium content when they reach their upper cut-off voltage. Conventional Li Ion cells are easy to overcharge and once in this state they can continue to extract Lithium putting the cell in a dangerous mode and making it prone to fires and explosions."
Additions:
The newer 32115 cell reportedly has TWICE the power output of the 26650 unit discussed in this page
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Deletions:
Additions:
GM has put its full weight
behind A123's at the expense of all others/ link to story about GM volt∞
Experiments and Experience
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells, 10 each from two DeWalt 9360 36V lithium power tool battery packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11.5 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! Not bad for a three pound battery! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Oliver KB6BA is starting to experiment with these batteries. He is using two of the 6V 4.6AH commercial packs in series for portable HF operations. More info as it comes to my attention!
A123 Battery Sources
At the present time these batteries are available primarily from two sources. The RC industry vendors have several size and configuration packs at the 6V and 9V level. Series connecting two of the 6V packs is an easy way to go. For the homebrewer the best source of cells is a premade battery pack that can be easily disassembled. The DeWalt 9630 36 volt Lithium power tool battery packs contain ten of the A123 cells. These are often available from various sources (such as eBay) for reasonable prices (about $80 to $100 per pack, or $8 to $10 per cell). See links below.
A123 Battery Chargers
A good low cost and safe A123 battery charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total for a 4 cell series pack.) The cells can be charged in parallel, all 5 at once. The FMA charger runs from 12V and charges at up to 4 amps. The RC folks also have chargers for the 6V RC packs. See links below.
A123 Voltage Characteristics
Maximum voltage depends on the charger but is usually 3.6 or 3.7V per cell, which for a 4 cell series pack is 14.4V to 14.8V. The discharge voltage is fairly constant, remaining above 12.5V for most of the useful capacity. The voltages are an excellent match for the requirements of 12V automotive powered type equipment, such as ham radio gear.
Safety
The A123 cells are designed to completely deplete the Lithium from the cathode when fully charged, so there is no more lithium to plate on the anode. This prevents the dangerous conditions that occur with many other lithium batteries. Tests have been conducted charging A123 cells on regular lithium chargers to 4.2V. While this overcharging will shorten the life of the A123 cells, it did not cause dangerous cell swelling, overheating, etc.
From the A123 site:
"A123 materials are designed to ensure all the Lithium is fully extracted from the cathode when the battery is fully charged. As a result safety issues relating to overcharge are eliminated because there is no Lithium available to plate on the anode in an overcharged state. This is in contrast to conventional Li Ion cells, which only extract half their Lithium content when they reach their upper cut-off voltage. Conventional Li Ion cells are easy to overcharge and once in this state they can continue to extract Lithium putting the cell in a dangerous mode and making it prone to fires and explosions."
Weight Compared
An A123 standard M1 cell weighs 70g for 3.6V and 2.3AH capacity. This is in between
NiMH and
LiPo energy densities. A123 cells have about twice the energy per weight of
NiMH. They have considerably higher energy per pound than lead-acid, approximately 4 times the energy per pound. The voltage output is also better than lead acid, holding above 12.5V for most of the discharge cycle (depends on current).
link to spec sheet pdf∞
From the above link you can see that at 10A the output voltage of a single cell stays above 3V out to almost 2.0AH. This for a single cell rated at 2.3AH.
Simple Solar Charging
There has been some interest in solar chargers for the A123 batteries. One way to do this is to use balancing circuits on the cells that can handle the full output of the solar panel. So if the panel can put out, say 1A, then the balancer must be able to handle at least that current plus a bit more. The balancer consists of an FET switch, a voltage sensor and a resistor. When the voltage across the cell reaches the full charge value of 3.6V the load switches in and takes the charge current, plus a bit more, so the voltage drops a bit and the switch cycles, holding the charge voltage to the safe value. Since in unusual conditions (clouds reflecting the sun just right on a really clear day) the solar output can be above normal, the balancing circuit should be capable of dissipating about 150% of the solar nominal output current. A reverse current diode is also normally employed in the solar charging circuit to limit reverse current discharge when the panels are dark.
HowTo Build an A123 Battery Pack∞
Custom RC packs∞
Charging Characteristics and Safety∞
A123 motorcycle∞
Deletions:
Eric WD6CMU built a pack of these A123
LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells, 10 each from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11.5 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! Not bad for a three pound battery! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the
LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Oliver KB6BA is starting to experiment with these batteries. More info as it comes to my attention!
At the present time these batteries are available primarily from two sources. The RC industry vendors have several size and configuration packs at the 6V and 9V level. Series connecting two of the 6V packs is an easy way to go. For the homebrewer the best source of cells is a premade battery pack that can be easily disassembled. The DeWalt 36 volt Lithium power tool battery packs contain ten of the A123 cells. These are often available from various sources (such as eBay) for reasonable prices. See links below.
A good low cost and safe charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total.) The cells can be charged in parallel, all 5 at once. The FMA charger runs from 12V and charges at up to 4 amps. The RC folks also have chargers for the 6V RC packs. See links below.
HowTo Build an A123 Battery Pack∞
Custom RC packs∞
Additions:
At the present time these batteries are available primarily from two sources. The RC industry vendors have several size and configuration packs at the 6V and 9V level. Series connecting two of the 6V packs is an easy way to go. For the homebrewer the best source of cells is a premade battery pack that can be easily disassembled. The DeWalt 36 volt Lithium power tool battery packs contain ten of the A123 cells. These are often available from various sources (such as eBay) for reasonable prices. See links below.
A good low cost and safe charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total.) The cells can be charged in parallel, all 5 at once. The FMA charger runs from 12V and charges at up to 4 amps. The RC folks also have chargers for the 6V RC packs. See links below.
Deletions:
A good low cost and safe charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total.) The cells can be charged in parallel, all 5 at once. The FMA charger runs from 12V and charges at up to 4 amps.
The DeWalt 36 volt Lithium power tool battery packs contain ten of the A123 cells. These are often available from various sources (such as eBay) for reasonable prices.
Additions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells, 10 each from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11.5 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! Not bad for a three pound battery! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
The DeWalt 36 volt Lithium power tool battery packs contain ten of the A123 cells. These are often available from various sources (such as eBay) for reasonable prices.
Deletions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
The DeWalt 36 volt Lithium power tool battery packs contain ten the A123 cells. These are often available from various sources (such as eBay) for reasonable prices.
Additions:
Additions:
The DeWalt 36 volt Lithium power tool battery packs contain ten the A123 cells. These are often available from various sources (such as eBay) for reasonable prices.
Deletions:
The
DeWalt 36 volt Lithium power tool battery packs contain ten the A123 cells. These are often available from various sources (such as eBay) for reasonable prices.
Additions:
Eric WD6CMU built a pack of these A123
LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran it for 30 seconds during which time the output voltage remained above 12 volts!!! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the
LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
A good low cost and safe charger is the FMA Cellpro A123 charger. Link below. This charger balances the voltages of each cell (it requires wires across each cell, 5 wires total.) The cells can be charged in parallel, all 5 at once. The FMA charger runs from 12V and charges at up to 4 amps.
The
DeWalt 36 volt Lithium power tool battery packs contain ten the A123 cells. These are often available from various sources (such as eBay) for reasonable prices.
Deletions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran them for 30 seconds during which time the output voltage remained above 12 volts!!! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Additions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. Later Eric put a 12 volt 200 amp test load on this battery and ran them for 30 seconds during which time the output voltage remained above 12 volts!!! These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Deletions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Additions:
Eric WD6CMU built a pack of these A123 LiFePO4 cells and brought it to Field Day 2007. His battery has 20 cells from two DeWalt packs wired in 4S5P configuration (4 series cells in 5 parallel stacks). This battery is rated 14.5 volts at about 11 amp hours. The battery itself weighs only about 3 pounds!!! (A gel battery of this capability would weigh 10 pounds or more). We connected this pack to my Hercules II 500 watt output HF amplifier that draws up to approximately 80 amps peak and made a couple of contacts on Field Day with this battery powering the kilowatt input of the amplifier. Later Eric used it to start his toyota truck. These batteries have very good characteristics for Ham Radio use. The voltage of 4 cells in series is compatible with 12 volt equipment, staying below 15 volts. This is in contrast to Lithium Polymer and other Lithium Ion batteries whose 4 cell series voltages gets slightly too high at full charge for most 12 volt systems. In other areas the LiFePO4 is also superior in terms of high current capability for charge and discharge, and safety. These batteries do not have the explosive problems associated with many other Lithium chemistry batteries.
Oliver KB6BA is starting to experiment with these batteries. More info as it comes to my attention!
More Info
Additions:
This may be the battery we've been waiting for. High energy density, high current capacity, low weight, good safety characteristics, and voltage compatible with 12V ham radio systems...
Deletions:
This may be the battery we've been waiting for. High energy density, high current capacity, low weight, good safety characteristics, and voltage compatible with 12V ham radio systems...
Additions:
Deletions:
Additions:
Deletions:
Lithium Iron NanoPhosphate Batteries
LiFePO4 Batteries
This may be the battery we've been waiting for. High energy density, high current capacity, low weight, good safety characteristics, and voltage compatible with 12V ham radio systems...
AlanB