All manner of acronyms and abbreviations relating to electric assist get thrown around on these forums. You've got a DD motor, and your BMS on your lipo is malfunctioning, etc. Despite the fact that I have a bit of experience with electric assist and a grasp of some of the technical fundamentals, I don't even have all of these acronyms figured out. What is 12s, for example, in relation to controllers? Or 5C? Likewise, what, exactly, does 12T or 8T in relation to geared hub motors mean? I know it has to do with what are called fast or slow windings and thus with the top speed of which the motor is capable, but what does the T in this truncation actually stand for?
My point here is that, if some of the acronyms and abbreviations create a bit of difficulty for someone who has a basic grasp of the technology, they must be totally intimidating to folks who are quite new to electric assist and do not have much exposure to the technical side of it. So why don't we start a thread, and maybe sticky it, where the various acronyms and abbreviations used in these forums are explained? Let me start by offering definitions of some that I understand to some extent.
Ah = amp hours. An indication of the depth of a battery's charge, and thus of it's energy storage capacity. Higher numbers typically mean greater capacity and thus greater travel range.
BMS = battery management system. An electronic system built into many (all?) lithium ion batteries that governs the electrical output of the battery (I'm a little vague on the technical aspects of this system: can anyone offer improvements to my definition?)
CA = Cycle Analyst. This is a meter developed and sold by ebikes.ca for electric assist systems. It has a range of capabilities for showing information about system status. It seems to be the gold standard for electric assist meters.
DD = a direct drive hub motor. This is one of two styles of hub motors, the other type being the geared hub motor. Geared motors have a built-in gear reduction system that allows the motor to run at a higher RPM than the rim rotation (a 5:1 ration seems common) while DD motors lack the gear reduction system and wheel RPM is in a 1:1 ratio with motor speed. Both designs have their pros and cons.
fet = The field-effect transistor (FET) is a transistor that uses an electric field to control the shape and hence the conductivity of a channel of one type of charge carrier in a semiconductor material. FETs are unipolar transistors as they involve single-carrier-type operation. (from Wikipedia)
GNG = a brand of mid-drive electric assist systems. This company primarily makes assist systems that interface with a bicycle's already-existing drive-train (crank arms, chain rings, chain, and pedals)
LiFePO4 = The lithium iron phosphate (LiFePO4) battery, also called LFP battery (with "LFP" standing for "lithium ferrophosphate"), is a type of rechargeable battery, specifically a lithium-ion battery, which uses LiFePO4 as a cathode material. LiFePO4 batteries have somewhat lower energy density than the more common LiCoO2 design found in consumer electronics, but offers longer lifetimes, better power density (the rate that energy can be drawn from them) and are inherently safer. LiFePO4 is finding a number of roles in vehicle use and backup power. (from Wikipedia)
lipo = Lithium-ion polymer batteries, polymer lithium ion or more commonly lithium polymer batteries (abbreviated Li-poly, Li-Pol, LiPo, LIP, PLI or LiP) are rechargeable (secondary cell) batteries. LiPo batteries are usually composed of several identical secondary cells in parallel to increase the discharge current capability, and are often available in series "packs" to increase the total available voltage. (from Wikipedia)
lion = Lithium Ion: denotes the family of batteries. A lithium-ion battery (sometimes Li-ion battery or LIB) is a member of a family of rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge, and back when charging. Li-ion batteries use an intercalated lithium compound as the electrode material, compared to the metallic lithium used in the non-rechargeable lithium battery. (from Wikipedia)
LVC = Low voltage cut-off: a device in the ESC (Electronic Speed Controller) which senses battery voltage and, particularly for Lipo, slows or stops your motor before you drain the battery too far and harm it. (from http://www.rcgroups.com/forums/showthread.php?t=1170796 - see also http://en.wikipedia.org/wiki/Cutoff_voltage)
mosfet = The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a transistor used for amplifying or switching electronic signals. Although the MOSFET is a four-terminal device with source (S), gate (G), drain (D), and body (B) terminals,[1] the body (or substrate) of the MOSFET often is connected to the source terminal, making it a three-terminal device like other field-effect transistors. (from Wikipedia)
p = when immediately preceded by a numeral, the letter "p" (or "P") often stands for "parallel." On these forums, this usually refers to a way of wiring together batteries or battery packs; e.g. "2p" could refer to 2 batteries or packs wired together in parallel. From Wikipedia: "Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. . . Components connected in parallel are connected so the same voltage is applied to each component."
s = when immediately preceded by a numeral, the letter "s" (or "S") often stands for "series." On these forums, this usually refers to a way of wiring together battery cells; e.g., "12s" could refer to 12 battery cells wired in series. From Wikipedia: "Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. Components connected in series are connected along a single path, so the same current flows through all of the components."
v = when immediately preceded by a numeral, the letter "v" (or "V") often stands for "volts." Thus, "36v" is typically an abbreviation for "36 volts."
? = (help here, please, by adding more entries)
I haven't come close to exhausting the range of acronyms and abbreviations used on these forums. Please pitch in to this thread with definitions of some acronyms and abbreviations you understand. You will be doing a service to those who have become interested in this technology but who are not yet educated in its details. Corrections to my own definitions will be appreciated as well.
My point here is that, if some of the acronyms and abbreviations create a bit of difficulty for someone who has a basic grasp of the technology, they must be totally intimidating to folks who are quite new to electric assist and do not have much exposure to the technical side of it. So why don't we start a thread, and maybe sticky it, where the various acronyms and abbreviations used in these forums are explained? Let me start by offering definitions of some that I understand to some extent.
Ah = amp hours. An indication of the depth of a battery's charge, and thus of it's energy storage capacity. Higher numbers typically mean greater capacity and thus greater travel range.
BMS = battery management system. An electronic system built into many (all?) lithium ion batteries that governs the electrical output of the battery (I'm a little vague on the technical aspects of this system: can anyone offer improvements to my definition?)
CA = Cycle Analyst. This is a meter developed and sold by ebikes.ca for electric assist systems. It has a range of capabilities for showing information about system status. It seems to be the gold standard for electric assist meters.
DD = a direct drive hub motor. This is one of two styles of hub motors, the other type being the geared hub motor. Geared motors have a built-in gear reduction system that allows the motor to run at a higher RPM than the rim rotation (a 5:1 ration seems common) while DD motors lack the gear reduction system and wheel RPM is in a 1:1 ratio with motor speed. Both designs have their pros and cons.
fet = The field-effect transistor (FET) is a transistor that uses an electric field to control the shape and hence the conductivity of a channel of one type of charge carrier in a semiconductor material. FETs are unipolar transistors as they involve single-carrier-type operation. (from Wikipedia)
GNG = a brand of mid-drive electric assist systems. This company primarily makes assist systems that interface with a bicycle's already-existing drive-train (crank arms, chain rings, chain, and pedals)
LiFePO4 = The lithium iron phosphate (LiFePO4) battery, also called LFP battery (with "LFP" standing for "lithium ferrophosphate"), is a type of rechargeable battery, specifically a lithium-ion battery, which uses LiFePO4 as a cathode material. LiFePO4 batteries have somewhat lower energy density than the more common LiCoO2 design found in consumer electronics, but offers longer lifetimes, better power density (the rate that energy can be drawn from them) and are inherently safer. LiFePO4 is finding a number of roles in vehicle use and backup power. (from Wikipedia)
lipo = Lithium-ion polymer batteries, polymer lithium ion or more commonly lithium polymer batteries (abbreviated Li-poly, Li-Pol, LiPo, LIP, PLI or LiP) are rechargeable (secondary cell) batteries. LiPo batteries are usually composed of several identical secondary cells in parallel to increase the discharge current capability, and are often available in series "packs" to increase the total available voltage. (from Wikipedia)
lion = Lithium Ion: denotes the family of batteries. A lithium-ion battery (sometimes Li-ion battery or LIB) is a member of a family of rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge, and back when charging. Li-ion batteries use an intercalated lithium compound as the electrode material, compared to the metallic lithium used in the non-rechargeable lithium battery. (from Wikipedia)
LVC = Low voltage cut-off: a device in the ESC (Electronic Speed Controller) which senses battery voltage and, particularly for Lipo, slows or stops your motor before you drain the battery too far and harm it. (from http://www.rcgroups.com/forums/showthread.php?t=1170796 - see also http://en.wikipedia.org/wiki/Cutoff_voltage)
mosfet = The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a transistor used for amplifying or switching electronic signals. Although the MOSFET is a four-terminal device with source (S), gate (G), drain (D), and body (B) terminals,[1] the body (or substrate) of the MOSFET often is connected to the source terminal, making it a three-terminal device like other field-effect transistors. (from Wikipedia)
p = when immediately preceded by a numeral, the letter "p" (or "P") often stands for "parallel." On these forums, this usually refers to a way of wiring together batteries or battery packs; e.g. "2p" could refer to 2 batteries or packs wired together in parallel. From Wikipedia: "Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. . . Components connected in parallel are connected so the same voltage is applied to each component."
s = when immediately preceded by a numeral, the letter "s" (or "S") often stands for "series." On these forums, this usually refers to a way of wiring together battery cells; e.g., "12s" could refer to 12 battery cells wired in series. From Wikipedia: "Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. Components connected in series are connected along a single path, so the same current flows through all of the components."
v = when immediately preceded by a numeral, the letter "v" (or "V") often stands for "volts." Thus, "36v" is typically an abbreviation for "36 volts."
? = (help here, please, by adding more entries)
I haven't come close to exhausting the range of acronyms and abbreviations used on these forums. Please pitch in to this thread with definitions of some acronyms and abbreviations you understand. You will be doing a service to those who have become interested in this technology but who are not yet educated in its details. Corrections to my own definitions will be appreciated as well.
