welders: THERMAL ARC ARCMASTER 200 AC/DC TIG

Recovered from the ElMoto crash: the welder of my dreams.

I can’t rush out to buy this right away, but this is what I want. I’ve been chatting with a good buddy of mine who’s been welding bike frames for decades now- he was very emphatic that you should NEVER use a MIG on a frame- not sure what the issue is, (“dont mig a bike frame ever “) but this is the unit he suggested. We’re talkin’ $2500, but it’s a pro rig…

Product page here.

* Exceptional Performance! Embedded microprocessor with digital controls, delivering perfectly smooth, stable arc characteristics for E6010 Cellulose and low hydrogen electrodes.
* Smart Logic and Easy Link! Prevents damage to the internal components if installed to improper voltage. Multi voltage 208-230/460 1 or 3 phase providing maximum flexibility.
* Thermal Overload Protection! Indicator alerts the operator if duty cycle is exceeded or airflow is blocked.
* Easy To Use! Simple, user friendly set-up and operation.
* Twist Lock Output Terminals! Allow for easy polarity reversal and cable change.
* Remote Receptacle Fitted! Allows remote devices to be connected for controlling amperage and output contactor.
* Standards Compliant Integrated VRD! Voltage Reduction Device reduces the OCV when the power supply is not in use. This all but eliminates the risk of electric shock to the operator from the secondary welding circuit.
* Job Save & Load! Allows operator to store up to 5 exact optimized welding parameters then digitally recall them with perfect repeatability.
* Smart Warning Diagnostics! Alerts operator to power supply abnormalities.
* Lift Start TIG! Provides TIG arc starting without use of high frequency.
* Hot Start! For easy arc starts when STICK welding.
* HF Arc Starting! Provides noncontact arc starting that eliminates tungsten or material contamination.
* True square wave output! Highly developed balance and cleaning features deliver an unbeatable welding performance with extended tungsten life on aluminum and magnesium alloys without the need for continuous high frequency.
* AC Frequency! Gives the operator control over weld bead shape.
* AC Balance! Allows you to fine tune the AC welding cycle.
* Rapid pulse output! Provides precision control over pulse on/off, pulse frequency, peak % time, background and peak amperage, initial and final slope times, and amperage.
* Intelligent heat sensing fan! Operates as needed to cool components & reduce airborne contaminants pulled through the power source.
__________________

Chip Yates, SWIGZ bike, Awesome awesomeness.

“2010 will be the pioneer bike for electric superbike racing…”

Great video about the SWIGZ strategy…  can you say, “data”?  (File under “scary engineers doing scary stuff with MATH.”)

The Motor Lineup- the Tried and True.

Let’s not reinvent the wheel here.

I’m a firm believer in seeing what works and using it.  If you’re an engineering student, or like tampering with the elemental forces of the Universe, you’re not going to agree with me, but if you’re looking to get a bike rolling in a reasonable amount of time with a reasonable investment, and with a good chance of success, I figure you want to see what everyone else is using, see how well it works and go with that.

I know.  Playing it safe is so boring.  Well, until you get on the (working) bike and go for a ride…

The easy way to do this is to simply look at what a supplier is putting up for sale.  Thunderstruck Motors, Cloud Electric and Electric Motorsports probably have the most common and complete lineup of good stuff…  all great companies to deal with, from what I’ve heard too.  They also all sell complete packages- the motors and controllers to match- a very helpful thing, especially when you consider warranty issues.  If you buy the package from one place, you get someone who’s going to stand behind what they recommend.

Here’s the basic breakdown.  First, the PMDC lineup.

(Shown above- Mars ME0709, Agni 95R, and Perm 132)

Permanent Magnet DC

Permanent Magnet DC motors fall into two basic classes- brushed and brushless.  The brushed models, like the Mars motors, are probably the most basic motor design you can go with, reasonably priced, and well proven in the light motorcycle/robot market.  You’re looking at around $500 for a 72V brushed model.  The controllers are in the $600 range. Brushless motors are basically very similar, but rely on the controller more since the controller performs the same function as the brushes.  You don’t, however, have to worry about maintenance- there are no brushes to wear out.

By the way.  There’s a very confusing tendency to refer to the Mars motors as an “Etek”.  I have a whole big post about that, you can read all about it, here, but the bottom line is there are no Etek motors anymore, unless you get something used or NOS.  Just sayin.  Also, I put together an explanation of axial and radial air-gap motors here.

The Agni and Perm are called a “pancake” design- an axial design that gives you high efficiency, more RPMs per volt, more RPMs period (the Agni spins up at 6500RPM) and a really handy shape for an electric motorcycle.  (When did they start calling the shape the “form factor”?  Around the same time that curtains became “window treatments”?)  With the increased efficiency you get a higher price- around $1000 to $1400 for the Perm, and around $1400 for the Agni.  Many of the race bikes run the Agni- some run two.

Series-wound DC motors

Probably the second most common motor type is the series-wound DC design.  These things are the workhorses of the EV industry- very common on car and truck conversions.  They’re big, heavy, but strong as an ox- and well tested in the field.  They have, as far as I understand it, huge amounts of low-end torque, but a limited high-RPM…  great for lifting loads and getting you rolling.  They also can take higher voltage- the D&D motors shown on Cloud Electric can handle up to 144V- way higher than a PMDC.  You’ll see them used in the bigger bikes, as well as the drag racers and experimental bikes- they’re a lot more common as simple industrial motors.

I’m showing a Netgain WarP 9″ “ImPulse” here, just because I like the name.  Sue me.  These sell for around $1500 and the biggest issue with them is that they’re long- sometimes a little tough to fit into a frame and line up with the drive sprocket.  You’ll also see guys pulling motors out of various salvage applications- forklifts being a popular one- and modifying them for bikes and cars.  This can be a tricky row to hoe- you can assume you’re going to have to do some modification to the motor, like the output shaft- and it may be a job getting the controller to work well for a bike.  It’s not a solution I’d use, but I can see how it’d be a fun challenge if I had the time and resources.

AC Induction motors

AC motors may be where we see the most development in the coming years- it seems to be where everyone is going, especially in the racing community.  AC motors have higher RPM capability and you can control the performance more, due to the nature of the physics of the motors and the controllers.  You’re going to see this in the better regenerative braking performance- “regen” of the motor- something we really haven’t talked about, and, honestly, something I don’t feel, after everything is said and done, is worth the extra overhead.  More on that later, but if you’re looking for regen, you probably want to look at an AC induction motor.

The standard package seems to be the AC-15 ($3200 with controller and kit) or the AC-20 ($3800 with controller and kit).  The AC-20 pulls 72-108V, 550A, ~50HP and 110FT-LBS .  They call it the “RACE MOTOR”.  In capital letters.  It’s a little more pricey than what we’ve looked at, but I think you can pull more out of it if you know what you’re doing, or want to learn.

As I’ve said, AC motors seem to be where people are heading- in particular, liquid cooled AC motors.  Several of the newest models of motors we’re seeing are offering a liquid cooling option, with various levels of benefits.  See more about that in my motor cooling stories.

Sepex (Separately Excited) DC motors

Finally, you got your Sepex motors.  Sepex means “separately exicted”, or that, well, I’m just going to rip a quote right from the Electric Motorsport page:

“Sepex motors are almost identical to traditional Series motors except for the way their field is wired and controlled. Unlike the Series motor whose armature and field windings are wired together in series, the SepEx motors field and armature windings are excited separately by special SepEx controllers that have wire leads to both the armature and the field. Separate control of the armature and field creates distinct advantages over a standard series wound motor, notably adjustable regenerative braking, higher rpm, longer power band, higher efficiency, and easy reversing.“ As far as I understand it, they’re also the top end of the efficiency range of any motor.  You do, again, have a problematic “form factor” to wrestle with- maybe not a great solution for a small bike, but certainly workable for a bigger one.

With the Sevcon PowerPak controller, the D&D runs at 425 A, 84V, 25 hp, gives you 4500RPM and sells complete for around $1500.  Honestly, it seems like a great price for a very versatile package- something you could set up to run easily, and then spend countless happy hours tweaking away to your heart’s content…

All in all, the motor decision is, in my opinion at least, not ultimately about performance.  The performance comparisons between any of these options is going to be offset by the other various factors of the build- the weight, the fit, and I come right back to motor basics.  That is, the motor you choose has to be able to handle the load you want to give it, that is the bottom line.  The ultimate performance of the thing has more to do with the batteries- how much current and voltage you can feed it for how long, and how fast- and other things like the weight of the bike.  You figure that out, then pick a motor that can handle it.

You chose a motor to fit your build, you don’t build a bike around a motor.  You build a bike around the entire system.  That’s where you look at what’s been done, what works, how it performs and how much you can afford.

Everything else is what my friend Adam lovingly refers to as “motor prOn”.  …and hell, we all need a little motor prOn.

Buckeye Bullet 2.5 claims battery EV WLSR of 307.7mph

HO.  LEEE.  CRAP.

“While the record is officially determined by averaging the speed of the two runs in the middle of the 12-mile course, the Bullet exited the flying mile at 320 mph (515km/h).”

Full story from Gizmag here.

Follow the Buckeye Bullet 2.5 blog, here.

Motor Cooling Questions: ANSWERED.

(Brammo) Secrets of (Empulse) Universe: REVEALED.

When Brammo announced the Empulse with a liquid cooled motor I started to suspect I was onto something with all this cooling hoo-haa I’ve been obsessed with.  It was Brammo, with their little cooling fan, that got me thinking it was a good idea in the first place.  Add to that what I learned about motor heating and building resistance and decreasing efficiency.  The reaction I got from people who actually understand this was, well, YEAH…  heat is bad. duh!

That’s all good, but I want proof.

It was pretty much unimaginable to me that this wasn’t a known quantity, and one of the guys on ElMoto.net rattled off an equation that sort of explained it-  the numbers are pretty simple.  An engineer really doesn’t need to run a test, Iike I would, they can run the numbers.

Then, I saw this.  The Parker Electromechanical Automation Blog.  More specifically, this.  The Parker MPP motor used for the Brammo.  To wit: The MPP powering the bike features Parker’s patent-pending internal cooling – a technology that increases the continuous torque output that virtually eliminates the peak region of the motor.

MOST importantly, I got me a graph.

You KNOW how I love me a good graph.

And HERE, my friends is the key to the Secrets of the Motor Cooling Universe. “Calculating Winding Temperature“, with numbers and graphs.  There, buried in the data and calculations, is the secret of the awesomeness of the cooling system designed into these motors.  In a normal motor the heat goes from the winding to the case, then to “ambient”- the outside environment.  Even if you wrap coils around the case, you’re going through the entire assembly.  These motors cool from the windings directly, eliminating the case.  That makes it cool faster.  If it cools faster, it doesn’t build up so much thermal momentum.  Also, your ambient temperature is having a direct, not intermediate, effect on the windings.  They’re staying cooler- more even- at the outset.

Now for the, (oh, jeeze…)  cool part.

The MPP series motors on the Parker Hannifin site are listed as liquid cooled rotary servo motors…  could this be the Holy Grail?  An off-the shelf servo motor for the next generation of awesome awesomeness?

And here is my wild guess on the motor in the Empulse.  The Parker Haniifin MPP SERIES MPP2708N- 1600 RPM,  20.3 kW,  26.6 HP.

Or not. “Parker will customize any MPP/MPJ motor to meet your specifi c system requirements. Parker does customs like no one else. We are specialists at customs, offering unrivaled custom motor solutions and support.” (Brammo: “Gimme a 20kW motor that runs at 6000 RM yo.  About a thousand of them, how’s that?”)

Powering VIR: TTXGP / Norton Electra at VIR via WTVR-TV CBS6

Some great stuff, interesting perspecitves:

This is really interesting.  An event promoted with social networking, viral marketing, internet news coverage and virtually no conventional media promotion or coverage.  A local traditional media station picks up on it, does this piece- that piece then then goes back to the internet…  hmmm.  Makes ya wonder…

My latest project…

(or, “and now for something completely different…”)  …but so cool for so many reasons.

First, rescued from the landfill via Scott and Craigslist.

Second, giving me a reason and method for using up the very last of my scooter batteries before I recycle them.

Third, mowing the lawn with electric?  ‎”A 2001 study showed that some mowers emit the same amount of pollution (emissions other than carbon dioxide) in one hour as driving a 1992 model car for 650 miles (1,050 km).[10] Another estimate puts the amount of pollution from a lawn mower at four times the amount from a car, per hour”

Here it is, all charging and everything…

Thanks Scott!

NOW to get to work on the solar charging…

The Women of Superbike Racing…

I’m working on a special treat… and this is a nice little tease that sets the stage. Enjoy, and thanks Terry!

Glossary of EV, Battery, Motor and General Electrical Terms

A

Accumulator – A rechargeable battery or cell (see also Secondary battery).

Actual Capacity or Available Capacity – The total battery capacity, usually expressed in ampere-hours or milliampere-hours, available to perform work. The actual capacity of a particular battery is determined by a number of factors, including the cut-off voltage, discharge rate, temperature, method of charge and the age and life history of the battery.

Actuator: A device that creates mechanical motion by converting various forms of energy to rotating or linear mechanical energy.

Alternate Fuel Vehicle A vehicle powered by fuel other than gasoline or diesel. Examples of alternative fuels are electricity, hydrogen, and CNG.

Alternating Current: The standard type of electricity in homes and the most effective way of powering an EV. In AC circuit the voltage swings between positive and negative meaning current flows in both directions (hence ‘alternating’)

Ambient Temperature (AMB): The temperature of the space (air) around the motor. Most motors are designed to operate in an ambient not to exceed 40C (104F).

Amp Hour or Ampere-Hour – A unit of measurement of a battery’s electrical storage capacity. Current multiplied by time in hours equals ampere-hours. One amp hour is equal to a current of one ampere flowing for one hour. Also, 1 amp hour is equal to 1,000 mAh

Ampere or Amp – An Ampere or an Amp is a unit of measurement for an electrical current. One amp is the amount of current produced by an electromotive force of one volt acting through the resistance of one ohm. Named for the French physicist Andre Marie Ampere. The abbreviation for Amp is A but its mathematical symbol is “I”. Small currents are measured in milli-Amps or thousandths of an Amp.

Ampere-Hour Capacity – The number of ampere-hours which can be delivered by a battery on a single discharge.

Anode – During discharge, the negative electrode of the cell is the anode. During charge, that reverses and the positive electrode of the cell is the anode. The anode gives up electrons to the load circuit and dissolves into the electrolyte.

Aqueous Batteries – Batteries with water-based electrolytes. The electrolyte may not appear to be liquid since it can be absorbed by the battery’s separator.

Armature: The rotating part of a brush type direct current (DC) motor. In an induction motor, the rotating part is called a rotor.

B

Battery – An electrochemical device used to store energy. The term is usually applied to a group of two or more electric cells connected together electrically. In common usage, the term “battery” is also applied to a single cell, such as a AA battery.

Battery Capacity – The electric output of a cell or battery on a service test delivered before the cell reaches a specified final electrical condition and may be expressed in ampere-hours, watt- hours, or similar units. The capacity in watt-hours is equal to the capacity in ampere-hours multiplied by the battery voltage.

Battery Charger – A device capable of supplying electrical energy to a battery.

Battery Electric Vehicle: See EV below, An electric vehicle whose electricity is exclusively stored in batteries rather than a fuel cell or generator.

Battery Management System: mini onboard computer to monitor entire battery system and each individual battery. Also may be built into charging system.

Battery-Charge Rate – The current expressed in amperes (A) or milli amps (mA) at which a battery is charged.

Breakdown Torque: the maximum torque a motor will develop under increasing load conditions without an abrupt drop in speed and power. Sometimes called pull-out torque.

Brush: Current conducting material in a DC motor, usually graphite, or a combination of graphite and other materials. The brush rides on the commutator of a motor and forms an electrical connection between the armature and the power source.

C

C – Used to signify a charge or discharge rate equal to the capacity of a battery divided by 1 hour. Thus C for a 1600 mAh battery would be 1.6 A, C/5 for the same battery would be 320 mA and C/10 would be 160 mA. Because C is dependent on the capacity of a battery the C rate for batteries of different capacities must also be different.

Canadian Standards Association (CSA): The agency that sets safety standards for motors and other electric equipment used in Canada.

Capacitance: As the measure of electrical storage potential of a capacitor, the unit of capacitance is the farad, but typical values are expressed in microfarads (MFD).

Capacitor Start Motor: Or more specifically, Capacitor-Start, induction-run. Provides high starting and break-down torque, medium starting current. Used on hard starting applications such as compressors, positive displacement pumps, farm equipment, etc.

Capacitor-Start, capacitor-run: Similar to capacitor-start, except have higher efficiency. Generally used in higher HP single phase ratings.

Capacitor: A device that stores electrical energy. Used on single phase motors.

Capacity – The capacity of a battery is a measure of the amount of energy that it can deliver in a single discharge. Battery capacity is normally listed as amp-hours (or milli amp-hours) or as watt-hours.

Cathode – Is an electrode that, in effect, oxidizes the anode or absorbs the electrons. During discharge, the positive electrode of a voltaic cell is the cathode. When charging, that reverses and the negative electrode of the cell is the cathode.

Cell – An electrochemical device, composed of positive and negative plates and electrolyte, which is capable of storing electrical energy. It is the basic “building block” of a battery.

Centrifugal Start Switch: A mechanism that disconnects the starting circuit (start winding) when the rotor reaches approximately 75% of operating speed (usually in 2 or 3 seconds).

Charge – The conversion of electric energy, provided in the form of a current, into chemical energy within the cell or battery.

Charge Rate – The amount of current applied to battery during the charging process. This rate is commonly expressed as a fraction of the capacity of the battery. For example, the C/2 or C/5.

Charging – The process of supplying electrical energy for conversion to stored chemical energy.

Commutator: The part of a DC motor armature that causes the electrical current to be switched to various armature windings. Properly sequenced switching creates the motor torque. The commutator also provides the means to transmit the electrical current to the moving armature through the brushes that ride on the commutator.

Constant-Current Charge – A charging process in which the current applied to the battery is maintained at a constant value.

Constant-Voltage Charge – A charging process in which the voltage applied to a battery is held at a constant value.

Continuous Duty: The operation of loads for over one hour.

Cutoff Voltage, final – The prescribed lower-limit voltage at which battery discharge is considered complete. The cutoff or final voltage is usually chosen so that the maximum useful capacity of the battery is realized. The cutoff voltage varies with the type of battery and the kind of service in which the battery is used. When testing the capacity of a NiMH or NiCD battery a cutoff voltage of 1.0 V is normally used. 0.9V is normally used as the cutoff voltage of an alkaline cell. A device that is designed with too high a cutoff voltage may stop operating while the battery still has significant capacity remaining.

Cycle – One sequence of charge and discharge.

Cycle Life – For rechargeable batteries, the total number of charge/discharge cycles the cell can sustain before it’s capacity is significantly reduced. End of life is usually considered to be reached when the cell or battery delivers only 80% of rated ampere- hour capacity. NiMH batteries typically have a cycle life of 500 cycles, NiCd batteries can have a cycle life of over 1,000 cycles. The cycle of a battery is greatly influenced by the type depth of the cycle (deep or shallow) and the method of recharging. Improper charge cycle cutoff can greatly reduce the cycle life of a battery.

D

DC Current: The power supply available from batteries, generators (not alternators), or a rectified source used for special purpose applications.

Deep Cycle – A cycle in which the discharge is continued until the battery reaches it’s cut-off voltage, usually 80% of discharge.

Depth of Discharge: A measure of how much energy has been withdrawn from a battery. It is expressed as a percentage of the total battery capacity. For example – if you use 25ah of a 100ah battery, that is running the battery to 25% DOD.

Direct Current (DC) – The type of electrical current that a battery can supply. One terminal is always positive and another is always negative.

Discharge – The conversion of the chemical energy of the battery into electric energy.

Discharge, deep – Withdrawal of all electrical energy to the end-point voltage before the cell or battery is recharged.

Discharge, high-rate – Withdrawal of large currents for short intervals of time, usually at a rate that would completely discharge a cell or battery in less than one hour.

Discharge, low-rate – Withdrawal of small currents for long periods of time, usually longer than one hour.

Drain – Withdrawal of current from a cell.

Dry Cell – A primary cell in which the electrolyte is absorbed in a porous medium, or is otherwise restrained from flowing. Common practice limits the term “dry cell” to the Leclanch‚ cell, which is the common commercial type.

Duty Cycle: The relationship between operating time and the resting time of an electric motor.

E

Efficiency: The ration of the useful work performed and the energy expended in producing it.

Electrochemical Couple – The system of active materials within a cell that provides electrical energy storage through an electrochemical reaction.

Electrode – An electrical conductor through which an electric current enters or leaves a conducting medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum. For electrolytic solutions, many solids, and molten masses, an electrode is an electrical conductor at the surface of which a change occurs from conduction by electrons to conduction by ions. For gases and vacuum, the electrodes merely serve to conduct electricity to and from the medium.

Electrolyte – A chemical compound which, when fused or dissolved in certain solvents, usually water, will conduct an electric current. All electrolytes in the fused state or in solution give rise to ions which conduct the electric current.

Electropositivity – The degree to which an element in a galvanic cell will function as the positive element of the cell. An element with a large electropositivity will oxidize faster than an element with a smaller electropositivity.

End-of-Discharge Voltage – The voltage of the battery at termination of a discharge.

Endshield: Also referred to as “End Bell”. The part of the motor that houses the bearing supporting the rotor and acts as a protective guard to the internal parts of the motor.

Energy – the capacity to perform work – expressed as capacity times voltage, or watt-hours.

Energy Density – Ratio of cell energy to weight or volume (watt-hours per pound, or watt-hours per cubic inch).

Excitation: The act of creating magnetic lines of force from a motor winding by applying voltage.

F

Field: The stationary part of a DC motor, commonly consisting of permanent magnets. Sometimes used also to describe the stator of an AC motor.

Final Voltage (see Cutoff voltage)

Float Charging – Method of recharging in which a secondary cell is continuously connected to a constant-voltage supply that maintains the cell in fully charged condition. Typically applied to lead acid batteries.

Force- any influence that causes a free body to undergo an acceleration.

Frame: Standardized motor mounting and shaft dimensions as established by NEMA or IEC.

Frequency: An expression of how often a complete cycle occurs. Cycles per second describe how many complete cycles occur in a given time increment. Hertz (hz) has been adopted to describe cycles per second so that time as well as number of cycles is specified. The standard power supply in North America is 60hz. Most of the rest of the world has 50hz power.

Fuel Cell Vehicle: A vehicle powered by a fuel cell, usually hydrogen. This is essentially an electric vehicle but using a liquid to store energy rather than a battery.

Full Load Amperes (FLA): Line current (amperage) drawn by a motor when operating at rated load and voltage on motor nameplate. Important for proper wire size selection, and motor starter or drive selection. Also called full load current.

Full-Load Torque: The force produced by a motor running at rated full-load speed at rated horsepower.

Fuse: A piece of metal, connected in the circuit to be protected, that melts and interrupts the circuit when excess current flows.

G

Galvanic Cell – A combination of electrodes, separated by electrolyte, that is capable of producing electrical energy by electrochemical action.

Gassing – The evolution of gas from one or both of the electrodes in a cell. Gassing commonly results from self-discharge or from the electrolysis of water in the electrolyte during charging.

Generator: Any machine that converts mechanical energy into electrical energy.

H

Hertz: Frequency, in cycles per second, of AC power. Named after H.R. Hertz, the German scientist who discovered electrical oscillations.

High Voltage Test: Application of a voltage greater than the working voltage to test the adequacy of motor insulation. Often referred to as high potential test or “hi-pot”.

Horsepower (HP): A measure of the rate of work. 33,000 pounds lifted one foot in one minute, or 550 pounds lifted one foot in one second. Exactly 746 watts of electrical power equals one horsepower.

Hybrid Electric Vehicle  A vehicle that combines conventional power production (e.g. an ICE) and an electric motor.

Hybrid Electric Vehicle: A vehicle which is powered by both electricity and another fuel, usually petrol/gas (eg Toyota Prius). This is usually just a more efficient way of using the standard fuel as there is no external source of electricity.

I

Impedance: The total opposition in an electric circuit to the flow of an alternating current. Expressed in ohms.

Induction Motor: The simplest and most rugged electric motor, it consists of a wound stator and a rotor assembly. The AC induction motor is named because the electric current flowing in its secondary member (the rotor) is induced by the alternating current flowing in its primary member (stator). the power supply is connected only to the stator. The combined electromagnetic effects of the two currents produce the force to create rotation.

Insulation: In motors, classified by maximum allowable operating temperature. NEMA Classifications include:

Integral Horsepower Motor: A motor rated one horsepower or larger at 1800RPM. By NEMA definitions, this is any motor having a three digit frame, for example 143T.

Intermittent Duty: The operation during alternate periods of load and rest. Usually expressed as 5 minutes, 30 minutes or

Internal Combustion Engine: the standard way to power a vehicle, this part is removed when converting to an electric car.

Internal Resistance – The resistance to the flow of an electric current within the cell or battery.

International Electrotechnical Commission (IEC): The worldwide organization that promotes international unification of standards or norms. Its formal decisions on technical matters express, as nearly as possible, an international consensus.

J

Joule- The work required to continuously produce one watt of power for one second; or one watt second (W·s) (compare kilowatt hour). This relationship can be used to define the watt.

K

Kilowatt: A unit of power equal to 1000 watts and approximately equal to 1.34 horsepower.

L

Lithium Ion  Or Lithium-ion polymer battery. are a type of rechargeable battery in which lithium ions move from the negative electrode (anode) to the positive electrode (cathode) during discharge, and from the cathode to the anode when charged.

Load: The work required of a motor to drive attached equipment. Expressed in horsepower or torque at a certain motor speed.

Locked Rotor Current: Measured current with the rotor locked and with rated voltage and frequency applied to the motor.

Locked Rotor Torque: Measured torque with the rotor locked and with rated voltage and frequency applied to the motor.

M

Magnetic Polarity: Distinguishes the location of North and South poles of a magnet. Magnetic lines of force emanate from the North pole of a magnet and terminate at the South pole.

Memory Effect – A phenomenon in which a cell, operated in successive cycles to less than full, depth of discharge, temporarily loses the remainder of its capacity at normal voltage levels (usually applies only to Ni-Cd cells). Note, memory effect can be induced in NiCd cells even if the level of discharge is not the same during each cycle. Memory effect is reversable.

Mounting, Basic Types: The most common motor mounts include: rigid base, resilient base C face or D flange, and extended through bolts.

Mush Coil: A coil made with round wire.

N

Nano Crystalline Motor – Conducts energy approx 10 times more efficiently than Iron core motors.

National Electric Code (NEC): A safety code regarding the use of electricity. The NEC is sponsored by the National Fire Protection Institute. It is also used by insurance inspectors and by many government bodies regulating building codes.

Negative Terminal – The terminal of a battery from which electrons flow in the external circuit when the cell discharges. See Positive Terminal.

Neighborhood Electric Vehicle. Used for short trips around ones community. Church, School, meeting, etc

NEMA (National Electrical Manufactures Association): A non-profit trade organization, supported by manufacturers of electrical apparatus and supplies in the United States. Its standards alleviate misunderstandings and help buyers select the proper products. NEMA standards for motors cover frame sizes and dimensions, horsepower ratings, service factors, temperature rises and performance characteristics.

Nonaqueous Batteries – Cells that do not contain water, such as those with molten salts or organic electrolytes.

O

ODP: Open Drip Proof, housing has openings in end shields and shell to allow air to cool the motor. Normally used in

Ohm’s Law – The formula that describes the amount of current flowing through a circuit. Ohm’s Law – In a given electrical circuit, the amount of current in amperes (I) is equal to the pressure in volts (V) divided by the resistance, in ohms (R). Ohm’s law can be shown by three different formulas:

Open Circuit – Condition of a battery which is neither on charge nor on discharge (i.e., disconnected from a circuit).

Open-Circuit Voltage – The difference in potential between the terminals of a cell when the circuit is open (i.e., a no-load condition).

Output Shaft: The shaft of a speed reducer assembly that is connected to the load. This may also be called the drive shaft or the slow speed shaft.

Overhung load: Is the perpendicular force pushing against the side of an output shaft. This force is either from a weight hanging on the output shaft or from a sprocket, pulley or gear being used on the shaft.

Oxidation – A chemical reaction that results in the release of electrons by an electrode’s active material.

P

Parallel Connection – The arrangement of cells in a battery made by connecting all positive terminals together and all negative terminals together. The voltage of the group remains the same as the voltage of the individual cell. The capacity is increased in proportion to the number of cells.

Partial Zero Emissions Vehicle PZEVs meet SULEV tailpipe emission standards, have zero evaporative emissions and a 15 year / 150,000 mile warranty. No evaporative emissions means that they have fewer emissions while being driven than a typical gasoline car has while just idling.

Permanent Split Capacitor (PSC): (Single Phase) Performance and applications similar to shaded pole motors, but more efficient, with lower line current and higher horsepower capabilities.

Phase: The number of individual voltages applied to an AC motor. A single-phase motor has one voltage in the shape of a sine wave applied to it. A three-phase motor has three individual voltages applied to it. The three phases are at 120 degrees with respect to each other so that peaks of voltage occur at even time intervals to balance the power received and delivered by the motor throughout its 360 degrees of rotation.

Plug-in Hybrid Electric Vehicle: A hybrid electric vehicle with a substantial battery pack which is able to be charged by an external source other than its fossil fuel (i.e. plugged into household electricity). These vehicles often have the ability to travel is a ‘pure electric mode’ without using any conventional fuels.

Plugging: A method of braking a motor that involves applying partial or full voltage in reverse in order to bring the motor to zero speed.

Polarity: As applied to electric circuits, polarity indicates which terminal is positive and which is negative. As applied to magnets, it indicates which pole is North and which pole is South.

Poles: Magnetic devices set up inside the motor by the placement and connection of the windings. Divide the number of poles into 7200 to determine the motor’s normal speed. For example, 7200 divided by 2 poles equals 3600RPM.

Positive Terminal – The terminal of a battery toward which electrons flow through the external circuit when the cell discharges. See Negative Terminal.

Power – the rate at which work is performed or energy is converted.

Primary Battery – A battery made up of primary cells. See Primary Cell.

Primary Cell – A cell designed to produce electric current through an electrochemical reaction that is not efficiently reversible. The cell, when discharged, cannot be efficiently recharged by an electric current. Alakline, lithium, and zinc air are common types of primary cells.

Pull-Up Torque: The minimum torque delivered by a motor between zero and the rated RPM, equal to the maximum load a motor can accelerate to rated RPM.

Pulse Width Modulation: a high-efficiency technique for controlling voltage output in a motor controller.

R

Rated Capacity – The number of ampere-hours a cell can deliver under specific conditions (rate of discharge, end voltage, temperature); usually the manufacturer’s rating.

Rechargeable – Capable of being recharged; refers to secondary cells or batteries.

Recombination – State in which the gases normally formed within the battery cell during its operation, are recombined to form water.

Reduction – A chemical process that results in the acceptance of electrons by an electrode’s active material.

Regenerative Braking Systems – An EV with a braking system that uses the braking RPM load to charge the onboard batteries.

Relay: A device have two separate circuits, it is constructed so that a small current in one of the circuits controls a large current in the other circuit. A motor starting relay opens or closes the starting circuit under predetermined electrical conditions in the main circuit (run winding).

Reluctance: The characteristics of a magnetic field which resists the flow of magnetic lines of force through it.

Resistor: A device that resists the flow of electrical current for the purpose of operation, protection or control. There are two types of resistors-fixed and variable. A fixed resistor has a fixed value of ohms while a variable resistor is adjustable.

Rotation: The direction in which a shaft turns is either clockwise (CW) or counterclockwise (CCW). When specifying rotation, also state if viewed from the shaft end or the opposite shaft end of the motor.

Rotor: The rotating component of an induction AC motor. It is typically constructed of a laminated, cylindrical iron core with slots of cast-aluminum conductors. Short-circuiting end rings complete the “squirrel cage,” which rotates when the moving magnetic field induces current in the shorted conductors.

S

Seal – The structural part of a galvanic cell that restricts the escape of solvent or electrolyte from the cell and limits the ingress of air into the cell (the air may dry out the electrolyte or interfere with the chemical reactions).

Secondary Battery – A battery made up of secondary cells. See Storage Battery; Storage Cell.

Self Discharge – Discharge that takes place while the battery is in an open-circuit condition.

Separator – The permeable membrane that allows the passage of ions, but prevents electrical contact between the anode and the cathode.

Series Connection – The arrangement of cells in a battery configured by connecting the positive terminal of each successive cell to the negative terminal of the next adjacent cell so that their voltages are cumulative. See Parallel Connection.

Service Factor: A measure of the overload capacity built into a motor. A 1.15 SF means the motor can deliver 15% more than the rated horsepower without injurious overheating. A 1.10 SF motor should not be loaded beyond its rated horsepower. Service factors will vary for different horsepower motors and for different speeds.

Shaded Pole Motor: (Single Phase) Motor has low starting torque, low cost. Usually used in direct-drive fans and small blowers, and in small gearmotors.

Shallow Cycling – Charge and discharge cycles which do not allow the battery to approach it’s cutoff voltage. Shallow cycling of NiCd cells lead to “memory effect”. Shallow cycling is not detrimental to NiMH cells and it is the most beneficial for lead acid batteries.

Shelf Life – For a dry cell, the period of time (measured from date of manufacture), at a storage temperature of 21 degrees C (69 degrees F), after which the cell retains a specified percentage (usually 90%) of its original energy content.

Short-Ciruit – A condition that occurs when a short electrical path is unintentionally created. Batteries can supply hundreds of amps if short-circuited, potentially melting the terminals and creating sparks.

Split Phase (or more specifically Split-Phase start-induction run): (Single Phase) Motor has moderate starting torque, high breakdown torque. Used on easy-starting equipment, such as belt-driven fans and blowers, grinders, centrifugal pumps, gearmotors, ect.

Starting Torque: Force produced by a motor as it begins to turn from standstill and accelerate (sometimes called locked rotor torque).

Starting-Lighting-Ignition (SLI) Battery – A battery designed to start internal combustion engines and to power the electrical systems in automobiles when the engine is not running. SLI batteries can be used in emergency lighting situations.

Stationary Battery – A secondary battery designed for use in a fixed location.

Stator: The fixed part of an AC motor, consisting of copper windings within steel laminations.

Storage Battery – An assembly of identical cells in which the electrochemical action is reversible so that the battery may be recharged by passing a current through the cells in the opposite direction to that of discharge. While many non-storage batteries have a reversible process, only those that are economically rechargeable are classified as storage batteries. Synonym: Accumulator; Secondary Battery. See Secondary Cell.

Storage Cell – An electrolytic cell for the generation of electric energy in which the cell after being discharged may be restored to a charged condition by an electric current flowing in a direction opposite the flow of current when the cell discharges. Synonym: Secondary Cell. See Storage Battery.

T

Taper Charge – A charge regime delivering moderately high-rate charging current when the battery is at a low state of charge and tapering the current to lower rates as the battery becomes more fully charged.

Temperature Rise: The amount by which a motor, operating under rated conditions, is hotter than its surrounding ambient temperature.

Temperature Tests: These determine the temperature of certain parts of a motor, above the ambient temperature, while operating under specific environmental conditions.

Terminals – The parts of a battery to which the external electric circuit is connected.

Thermal Protector: A device, sensitive to current and heat, which protects the motor against overheating due to overload or failure to start. Basic types include automatic rest, manual reset and resistance temperature detectors.

Thermal Runaway – A condition whereby a cell on charge or discharge will destroy itself through internal heat generation caused by high overcharge or high rate of discharge or other abusive conditions.

Thermocouple: A pair of dissimilar conductors joined to produce a thermoelectric effect and used to accurately determine temperature. Thermocouples are used in laboratory testing of motors to determine the internal temperature of the motor winding.

Thermostat: A protector, which is temperature-sensing only, that is mounted on the stator winding. Two leads from the device must be connected to control circuit, which initiates corrective action. The customer must specify if the thermostats are to be normally closed or normally open.

Torque: The turning effort or force applied to a shaft, usually expressed in inch-pounds or inch-ounces for fractional and sub-fractional HP motors.

Transformer: Used to isolate line voltage from a circuit or to change voltage and current to lower or higher values. Constructed of primary and secondary windings around a common magnetic core.

Trickle Charging – A method of recharging in which a secondary cell is either continuously or intermittently connected to a constant-current supply that maintains the cell in fully charged condition.

U

Underwriters Laboratories (UL): Independent United States testing organization that sets safety standards for motors and other electrical equipment.

V

Vent – A normally sealed mechanism that allows for the controlled escape of gases from within a cell.

Volt – The unit of measurement of electromotive force, or difference of potential, which will cause a current of one ampere to flow through a resistance of one ohm. Named for Italian physicist Alessandro Volta (1745-1827).

Voltage, cutoff – Voltage at the end of useful discharge. (See Voltage, end-point.)

Voltage, end-point – Cell voltage below which the connected equipment will not operate or below which operation is not recommended.

Voltage, nominal – Voltage of a fully charged cell when delivering rated current.

Voltage: A unit of electromotive force that, when applied to conductors, will produce current in the conductors.

W

Watt: The amount of power required to maintain a current of 1 ampere at a pressure of one volt when the two are in phase with each other. One horsepower is equal to 746 watts. Watts = amperes multiplied by volts. 120 volt @ 1 amp = 12 volts @ 10 amps.

Wet Cell – A cell, the electrolyte of which is in liquid form and free to flow and move.

Winding: Typically refers to the process of wrapping coils of copper wire around a core, usually of steel. In an AC induction motor, the primary winding is a stator consisting of wire coils inserted into slots within steel laminations. The secondary winding of an AC induction motor is usually not a winding at all, but rather a cast rotor assembly. In a permanent magnet DC motor, the winding is the rotating armature.

Work – the amount of energy transferred by a force acting through a distance.

Compiled via The Electric Motor Warehouse, The Environmentaly Friendly Store and Green Batteries.

Stuff I’ve Learned: Battery Management Systems

…or, “What the HELL is a BMS anyway?”

Here’s the issue.  In any electric vehicle you’re building up battery packs from cells with low voltage- lets keep it simple and say you’re using six 12V batteries- and wiring them together in series to add up the voltage.  Six 12V batteries in series will add up to 72V.  Nice.  Keep in the back of your mind- wiring the batteries in series adds the voltage but not the capacity.  If you want to add up the capacity- say you’re working with 20aH batteries, then you have to wire them in parallel.  Two 12V 20 aH batteries wired in parallel gives you 12V, with 40 aH.

So, OK, I have six batteries giving me 72V.  Let’s charge them up.  I can do it two ways- with a 12V charger, doing each battery separately, and the charger will monitor the battery, top it up, and shut off at a prescribed, and constant, voltage.  If I use the same charger on every battery, every battery will be exactly at the same state of charge.

The other approach is to charge the whole pack with one 72V charger.  This is easier, but you may or may not hit the same state of charge for each battery.  This is because every battery has a different set of characteristics- internal resistance, capacity, like that.  When you hook up a bunch of batteries in parallel to a charger, the charger gets access to both ends of each battery.  It can charge and monitor each battery directly.  In series, it’s more like a bucket brigade- the charge goes through each battery and on to the next.  Because each battery is different, each battery will find it’s own level, and not necessarily the level of the pack.

This doesn’t only apply to charging, it works for discharging too.  If you start with a bunch of cells at identical states of charge, they discharge at different rates and they charge at different rates, sooner or later you’re going to have a pack with wildly varying voltage between batteries.  For six lead batteries, it’s not so much of a big deal.  You can check and charge them individually pretty easily, and if you accidentally cook a battery, they’re cheap enough to replace.

Not so with lithium and other battery types.  These things are both delicate and expensive. Dangerous, too.  Discharging or charging at too high a rate can be damaging, or even catastrophic.  Enter the BMS.

The Battery Management System is set up to monitor the state of charge and discharge of each cell. It will see if one cell is low, and ask for more charge.  When a cell reaches a certain point, it will shunt the charge to the rest of the system.  It does the reverse on the discharge leg of the cycle.

I found this “mini-BMS” video to be the single most helpful explanation/demonstration of how a BMS works.  Take a look.

On a mini-BMS you get small modules on every cell.  The diagram at the top of the page is a conventional BMS with individual leads going to each cell, then connecting to the charger/controller circuits.

This is all swell, but the one issue is that there’s a lot of development going on in the BMS segment, and that’s because, well, they blow up a lot.  They’re expensive, too.  Within a year or two, the BMS concept may well be the biggest area of development and change you’ll see in the EV market.

One approach, by the way, is to avoid the BMS issue altogether- as per Ed “Juiced” Fargo’s “Non-BMS” solution.  Ed drag races electric motorcycles, and has melted more than his share of BMSs.  He’s stuffing enormous amounts of current through the system, and the normal BMS is just not designed for it.  His answer?  Forget about the discharge rate, and just make sure you’re starting with a constant state of charge- by using individual chargers.  He’ll have several Headway cells wired together in parallel- a total voltage of 3.2V, but a capacity of maybe 40aH, and have one charger wired to that sub-pack.  Then all the sub-packs are wired in series to get his voltage up to 72V.  All told, he has 24 individual, inexpensive chargers feeding his 24 parallel clusters.

Probably the single biggest reason, besides the cost, I decided to go with cheap AGM batteries rather than spring for the Headways I really want was the BMS issue.  I feel like this is something that just isn’t quite there yet.  Several manufacturers incorporate the BMS into the battery, (Valence, notably, the company that supplies Brammo) thus giving you a system that has some warranty protection for both the batteries and the BMS- as it is now, if you pull one battery and another BMS and one, or both, fail- both the battery manufacturer and the BMS guys can point at each other and say it was the other product’s fault.

They don’t call it the bleeding edge of technology for nothin’!