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I'm going to add my report on lithium batteries I originally posted someplace else, because it's very relevant to building lasers. It would make a good sticky, but I don't know how to do that, here. Not all lithium batteries are the same, and so they have industry standardized codes for the different types, for different uses.
Regular Lithium Ion and Lithium Polymer batteries fall into the first category. The primary difference between them is that the cylindrical cells use a liquid electrolyte, and a metal body, while the soft pack batteries use a polymerized electrolyte, so they can be housed in foiled plastic envelops. Here is how the coding of lithium batteries breaks down, starting with the lower discharge rate, higher capacity, standard type batteries, ICR:
ICR: LiCoO2 (Lithium Cobalt Oxide)
It's important to remember that this type of battery is UNSAFE to over discharge, and are the most prone to failure, and the primary symptom of failure involves a huge ball of fire that burns your house down. They are ALWAYS used with some kind of protection circuit to prevent this, albeit part of the device using the cells, like your mobile phone has. Caution should be used when deploying ICR batteries. On the other hand, the high discharge types don't suffer from from over discharge related failures, and are meant to be practically shorted out. These are most commonly used now, for portable vaporizers, like "vape pens", so they are fairly common, just expensive. These, however, have about half the capacity of the older type lithium cells. And ALL lithium batteries require a special charger that will NEVER allow the total voltage to exceed the maximum allowable voltage, they reduce the charge rate accordingly when the batteries reach that voltage, then decrease it to keep that voltage until they don't take any more current. Electronics meant to use lithium batteries will usually have this built into them. For other uses, you can buy cells with protection pcb's built into (or onto) them.
High Discharge Capacity
IFR: LiFePo4 (Lithium Iron Phosphate) One unique thing about these is that they have 4 times the number of charge cycles or lifetime.
IMR: LiMn2O4 (Lithium Manganese Oxide)
INR: LiNiMnCoO2 (Lithium Iron Phosphate With Nickel/Manganese Oxide)
Primary cells (non-rechargeable, but usually have twice the capacity of rechargeable batteries)
ER: Li-SOCl2 (Lithium Thionyl Chloride)
LS: Li-SOCl2 (Lithium Thionyl Chloride)
CR: Li-MnO2 (Lithium-Manganese Dioxide)
BR: Li-(CF)x (Lithium Carbon Monofluoride)
FR: Li-FeS2 (Lithium-Iron Disulfide) - 1.5 to 1.8V "Energizer Ultimate"
The numbering usually refers to the size of the battery, a 14500 refers to "AA" size of 14mm x 45mm, a 18650 is 18mm x 65mm, and so on. At least with ICR, IMR, INR, and IFR types. So, "AA" size 3.7V primary cells are ER14500 or LS14500.
I'm going to add a breakdown on C rating.
There are a couple of factors to consider when trying to quantify capacity and discharge capacity, how much current, and how fast. The "C" number is the minimum time the battery can be safely discharged completely in, quantified in fractions of one hour. So when they give you the capacity in mAh, they are telling you the 1C for the battery. So a 5Ah battery can be discharged completely if discharged @ 5A for one hour. This way you can multiply the mAh capacity by the C number to calculate the maximum sustainable discharge rate, in amps, with the time you can do it in, as the given.
Let's say we have 2 identical looking packs, same size and weight, same capacity, 5Ah, but we'll make the first one a 20C and the other a 30C. The 20C battery can be discharged in (60/20=3) 3 minutes @ (20x5=100) 100A. The 30C battery can be discharged in (60/30=2) 2 minutes @ (30x5=150) 150A. Likewise, an identical battery with a 60C rating can be discharged @ 300A in a minute flat.
More info on lithium batteries here:
https://en.wikipedia.org/wiki/Lithium_battery
I have an NUBM44 with a 4.5A driver running on just two, AAA size IMR 10440 cells, currently! That's a hell of a lot of laser for those tiny batteries, but they can do it! They just don't do it for very long, but a few minutes on a charge is fine for a laser pointer. Currently, only EFEST sells high discharge capacity cells in this size, IMR 10440. But if you are trying to force as much laser as possible into the smallest host you can get it into, these are the way to do it.
Regular Lithium Ion and Lithium Polymer batteries fall into the first category. The primary difference between them is that the cylindrical cells use a liquid electrolyte, and a metal body, while the soft pack batteries use a polymerized electrolyte, so they can be housed in foiled plastic envelops. Here is how the coding of lithium batteries breaks down, starting with the lower discharge rate, higher capacity, standard type batteries, ICR:
ICR: LiCoO2 (Lithium Cobalt Oxide)
It's important to remember that this type of battery is UNSAFE to over discharge, and are the most prone to failure, and the primary symptom of failure involves a huge ball of fire that burns your house down. They are ALWAYS used with some kind of protection circuit to prevent this, albeit part of the device using the cells, like your mobile phone has. Caution should be used when deploying ICR batteries. On the other hand, the high discharge types don't suffer from from over discharge related failures, and are meant to be practically shorted out. These are most commonly used now, for portable vaporizers, like "vape pens", so they are fairly common, just expensive. These, however, have about half the capacity of the older type lithium cells. And ALL lithium batteries require a special charger that will NEVER allow the total voltage to exceed the maximum allowable voltage, they reduce the charge rate accordingly when the batteries reach that voltage, then decrease it to keep that voltage until they don't take any more current. Electronics meant to use lithium batteries will usually have this built into them. For other uses, you can buy cells with protection pcb's built into (or onto) them.
High Discharge Capacity
IFR: LiFePo4 (Lithium Iron Phosphate) One unique thing about these is that they have 4 times the number of charge cycles or lifetime.
IMR: LiMn2O4 (Lithium Manganese Oxide)
INR: LiNiMnCoO2 (Lithium Iron Phosphate With Nickel/Manganese Oxide)
Primary cells (non-rechargeable, but usually have twice the capacity of rechargeable batteries)
ER: Li-SOCl2 (Lithium Thionyl Chloride)
LS: Li-SOCl2 (Lithium Thionyl Chloride)
CR: Li-MnO2 (Lithium-Manganese Dioxide)
BR: Li-(CF)x (Lithium Carbon Monofluoride)
FR: Li-FeS2 (Lithium-Iron Disulfide) - 1.5 to 1.8V "Energizer Ultimate"
The numbering usually refers to the size of the battery, a 14500 refers to "AA" size of 14mm x 45mm, a 18650 is 18mm x 65mm, and so on. At least with ICR, IMR, INR, and IFR types. So, "AA" size 3.7V primary cells are ER14500 or LS14500.
I'm going to add a breakdown on C rating.
There are a couple of factors to consider when trying to quantify capacity and discharge capacity, how much current, and how fast. The "C" number is the minimum time the battery can be safely discharged completely in, quantified in fractions of one hour. So when they give you the capacity in mAh, they are telling you the 1C for the battery. So a 5Ah battery can be discharged completely if discharged @ 5A for one hour. This way you can multiply the mAh capacity by the C number to calculate the maximum sustainable discharge rate, in amps, with the time you can do it in, as the given.
Let's say we have 2 identical looking packs, same size and weight, same capacity, 5Ah, but we'll make the first one a 20C and the other a 30C. The 20C battery can be discharged in (60/20=3) 3 minutes @ (20x5=100) 100A. The 30C battery can be discharged in (60/30=2) 2 minutes @ (30x5=150) 150A. Likewise, an identical battery with a 60C rating can be discharged @ 300A in a minute flat.
More info on lithium batteries here:
https://en.wikipedia.org/wiki/Lithium_battery
I have an NUBM44 with a 4.5A driver running on just two, AAA size IMR 10440 cells, currently! That's a hell of a lot of laser for those tiny batteries, but they can do it! They just don't do it for very long, but a few minutes on a charge is fine for a laser pointer. Currently, only EFEST sells high discharge capacity cells in this size, IMR 10440. But if you are trying to force as much laser as possible into the smallest host you can get it into, these are the way to do it.
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