You're receiving this newsletter because you asked to hear of updates or news of my "green" energy projects in Victoria BC (ocean wave power, a motor system to make "any old car" into a plug-in hybrid, and better large batteries) or because I thought you'd be interested. If you don't want any more, please reply and let me know. It isn't my intent to send unwanted "spam".

Regards, Craig

Turquoise Energy Ltd. News #9

Craig Carmichael   November 1st 2008


The Month in Brief (overview... summary... the short version!)
Or, here's the Super Short version!

* Electric Hubcap Motor Moves Car!
* Batteries start to Charge!
* Promising New Battery Chemicals!
BC's Goals? - an editorial comment
Proposed First Electric Hubcap Motor Making Class/Workshop
Electric Hubcap Car Drive Project, Long, Detailed Report
Turquoise Battery Project, Long, Detailed Report

The Month in Brief

   Everything seemed close to fruitition at the end of September and yet nothing much could be claimed for results. October got better!

Car pulling out on 36 volts Electric Hubcaptm power
(movie URL below)

   On the 6th, after sending the September newsletter, I glued six more magnets onto the car wheel rotor. It look quite impressive - "industrial".

   But it didn't seem to increase the propulsion at 24 volts. Worse, the motor controller burned up - again - when I tried to roll the car. That was a bad moment.
   I made a new motor controller and a couple of mechanical improvements and on the 20th I tried it out with 36 volts. The car moved on level pavement, if only slowly.
   Movie Clips

*   Wheel Spin Up: http://www.saers.com/~craig/LastSpinUp.AVI [22.5MB]
      At perhaps 1500-2000 RPM, this wheel has never before turned this fast!

*   Car Moves: http://www.saers.com/~craig/CarMoveWave.AVI [23MB]
      The pivotal event!
      (extra footage - the remote's "Stop" didn't turn the camera off.)

  The torque and power can and will be improved, but it looks like "all wheel drive", four motors, will probably be needed rather than just two, to have satisfactory power for highway speeds and hills. The essential plan for making "any old car" into a plug-in hybrid still works.
   Having recently located pre-made parts for most items, the motors will be amazingly easy to make! Most of the effort will instead be installing them, including mounting brackets, wiring and controls.

     The direct drive concept, now shown to work, is easily the lightest and most efficient possible means to propel a vehicle: 2/3 as much horsepower is required and it'll have half again the electric range per battery of everything else. That's better than anything you can buy today at any price. It's the future of vehicle propulsion.

   Also on the evening of October 6th, I finally tried some things that worked - not exactly as I'd envisioned them - and got a battery to charge.
   Then on the 9th, I tried making a "Ni-Ni" battery [1.1v] as an experiment. That charged too! That chemistry would be quite a simple battery to make at home, with energy density similar to Ni-Cd or Ni-MH. Then I found calcined zinc oxide. With a higher voltage than the others [1.6v+], Ni-CaZn cells are almost equally simple, promise considerably better energy density, and will cost less. La-CaZn holds considerable promise for even better density, but is more complex to make.
   My batteries still need much work.

BC's Goals?

   What does it say about the effectiveness of our society if the will to go to sustainable electric power runs from the premier on down, and yet there seems to be provided no channel for action or practical support to nurture and sustain vital breakthroughs in furtherance of our goals when once they make their appearance? It seems the province is now offering "savings of over $6000 on the purchase of a new fuel efficient car", but not $6 assistance to develop a means for eliminating the bulk of the fossil fuel usage of the entire province over the next few years.
   Most talented but unpaid innovators give up and get a job. When by some miracle they manage to develop a valuable product on their own puny resources, it is grabbed and used by industry, usually without recompense. (Less than 1% of inventors make good money off their inventions. Musicians with original work are much better protected.) Is that the process of energy innovation the premier is trying to promote?
   The whole face of transportation will be changed forever by better batteries, and by the Electric Hubcap type of drive motor and what automakers will eventually turn it into.
   I put the wave power on hold because it doesn't look like anybody will make the slightest use of even a superb, practical demonstrated working unit - or even permit it to be deployed and connected - even though west coast wave power would be 1/2 the price of the Site C dam, environmentally benign, and could be phased in incrementally.
   Here are new industries, new Boeings or Microsofts in potential. Who will grab them and take the lead: BC where they were invented, or Europe or China? It seems to me that currently we drift with no plan while everybody - government, business, investors, and the public - waits for somebody else to do everything for them.

First Proposed Class - Workshop

   When is a good time to offer workshops?...

   The batteries are certainly not ready. On the other hand, the prototype Electric Hubcaptm works, the design will now have improvements based on the deficiencies and strengths revealed in the tests, and it will be a very easy motor to construct and to duplicate.

   On balance I think it would be a good idea to hold an Electric Hubcap making and installing workshop/class with a number of sessions in the upcoming months, perhaps starting in January.

   The Electric Hubcap is not a finished product. More fabrication and trial of design variants would be of value. The microprocessor controls aren't ready and motor operation will be quite basic (drive power and forward/reverse, no regenerative braking or displays...) until they are.

   On the other hand, it would seem enough is known now to make reliable, workable motors and run cars with them, and if I on my own very meager resources try to get all the desired things tested alone, it could take a year or more and meanwhile nobody's driving on electricity, whereas if workshop participants each try a variant or two, much would be learned before the sessions end, the participants would have electric drive cars and know how to make them, and I would have some funds to continue the R & D for the batteries and the computer controls, which is otherwise about to go into very low gear. (When ready the computer controls would be provided at cost to workshop alumni.)
   So if anyone is eager to electrify their vehicle, please let me know! I'd be very pleased to run an early workshop series when about 4 or 5 people are signed up. The motors made at the workshop will certainly be better than my prototype, which has at least moved the car!

Here is a description of the proposed program as I currently see it, details subject to change:
Course Overview

* Instruction session: working principles of the Turquoise Energy Electric Hubcaptm vehicle drive motor and its ancillary components, as applied to creating a plug-in hybrid car and other useful applications.
* Motor making workshops as required to assemble the motors.
* Instruction session: motor controller details; simple controls details.
* Workshops: assembling the motor controllers and wiring boxes, and the simple controls.
* Instruction session: various aspects of installing the motors, and the computer controls.
* Motor installing workshops as required to get the cars going.
* Additional instruction and workshops as required to complete projects.
* Followup session(s) when computer controls are complete: install computer controls.

Participants should be mechanically inclined. Experience with design, fabrication and installation in any fields of metal working, mechanical, auto mechanics, electrical and electronics are assets. Participants are encouraged learn principles of construction during the workshops and do work on their own if and as convenient. Work will be inspected and discussed by me and by the other participants. Creative thought in adaptation to specific vehicles and improvements to systems is encouraged.

The object of this course is twofold:
(a) to have the participant create his or her own Electric Hubcap equipped super efficient plug-in hybrid vehicle or other similar motor installation of choice, and

(b) without obligation, to provide a trained nucleus of people to who are familiar with this exciting and promising new technology, the future of propulsion. They'll not only save on gas, they'll be engaged with the cutting edge of electric transportation technology.

I haven't specified the number of workshops for each phase: there's lots of new things here and it's hard to quantify how long the jobs will take. We'll continue for one or as many sessions as it takes to satisfy the class. Installating things in the car is the most time consuming part, and is likely to vary considerably by vehicle.

   There'll be three instructional manuals (or subjects in one large manual) to accompany the workshop: Making the Electric Hubcaptm Motor, Making the Electric Hubcaptm Motor Controller, and Installing the Electric Hubcaptm Drive System in a Vehicle. Writing of these proceeds apace.

   The tuition fee for the workshop program will be $2000, and the parts cost will be $900 per motor. That includes most everything: the motor, controller, wiring box, and cables. But (what else is new?): batteries not included.
   Unless they can be scaled up in diameter, magnets and coils, four motors would seem the necessary number to satisfactorily propel a typical smallish car.
   I think I should order/buy the parts, paid for in advance by the participants (at cost - but see below). That should bring some quantity discounts, and the materials would all be on hand when the workshop sessions commence. Perhaps the money for materials (as well as the tuition fee of course) can be made tax deductable and PST exempt - that would lower the costs for participants.
  I was surprised the materials for each complete motor installation cost so much when I added them all up. Anyone who wishes to provide some of the supplies themself is certainly welcome to do so. I will of course need to know what you are bringing before I order the parts. Particular items to provide that can save money are listed below.

Particular items to provide that can save money:

* car disk brake rotors - Honda Civic(?) rotors (10.25" diameter with a hub of 5.5" inside diameter) appear to be ideal for typical 4 lug bolt wheels. As rotors are perhaps $40 and two are used per motor, that's $320 for four motors. Anywhere that does auto brake repairs should have used rotors going into the garbage can. They don't have to be in great condition, though a pretty flat face to mount the magnets on is desirable.
* winding and casting or varnishing/baking your own coils. If the coils are $20 (though that price is not ascertained yet) and you can wind your own for $8, at 9 coils per motor that saves $432 for four motors. It is however quite a time consuming operation that would have to be mostly done outside workshop time after initial guidance and practice.
* Finding your own heavy copper wire, 200 amp circuit breakers, capacitors, wiring boxes and other electrical parts. Heavy #4 battery cables and #6 or #4 "cab tire" cables to the motor cost in the upper tens of dollars per motor. 200 amp breakers for the motor controller boxes (preferably aluminum boxes for heat dissipation) all add up.

The Electric HubcapTM Vehicle Drive Motor
October Gory Details

   The first thing to try to get more torque was obviously to fill the rotor with magnets. It had twelve, and I'd spaced them so six more could be added between. The rotor stuffed with magnets had a really "industrial" look that said "part of a Motor"!

   But then I tried it out. At 24 volts, the jacked up car wheel spun vigorously up to 680 RPM, the same speed as before and with about the same amps, and on the ground the car again didn't seem to quite want to move. I started it slowly down the street with the gas engine and turned on the juice, using a potentiometer on the passenger seat instead of the one on the gas pedal. At "max", one could feel vibration from the magnetic thrust, creating a bit of propulsion, but after a few seconds at "max" a transistor blew and burned the circuit board. Lots of smoke and flame. There seems to be nothing to tell you when you're crossing into the red zone until that sudden "BANG".

   I must say that was a bad moment. I reflected that perhaps after all I'd simply made everything just a bit too small and underpowered to succeed, and that maybe I should just abandon the whole motor project and leave the future of vehicle propulsion to somebody with more resources.
   But the motor was undamaged, I hadn't tried 36 volts yet (it would have been the next test), and I had one more motor controller circuit board and could soon rebuild the controller with a few more transistors and (doubtless) a new MOSFET driver chip.
   I had to give it a shot with 36 volts. If that would at least budge the car on flat ground and not burn out, a second motor should bring the power up to "driveable".

  I limited the PWM duty cycle to 80% max hoping to prevent another controller burn-out and made a couple of needed mechanical improvements. I finally spun the jacked up car wheel on October 20th after previous testing on the bench. With 36 volts, it spun up to what seemed like 1500-2000 RPM. 2000 RPM would be 200 Km/Hr, though of course the only load was the wheel. Accelerating, the motor may have drawn 60-80 or more amps, and it seemed to drop to around 40 amps once it was up to speed. (I suspect it was more on startup, probably well over 100, but the meter was too slow responding to catch it.)
   Then I took the car to a level cul-de-sac and tried driving it. On level pavement there were a couple of non-starters - until I remembered first to take the car out of gear... and then to turn off the parking brake.
   Then the car moved, though only slowly. One could hear the coils buzzing with the PWM and feel the push and the sudden small changes of force as the wheels turned and different groups of coils turned on and off.

After driving just 3 or 4 car lengths (twice), I went outside and felt the coils. They were very hot, some notably hotter than others. Not smoking - yet - but obviously the wiring is too light. (#10 feed wires & #14 coil windings - should increase those to about #6 & #12 or #11.) Then I felt the heat sink and the transistors in the motor controller, but they were only warm. The new MOSFETs certainly seem to generate less heat. The car moved, nothing blew up or burned, and I got a bit of footage! That was enough for one day!

What factors might have limited the performance?

1. the 80% PWM duty cycle.

2. a 6mm or so air gap. (It was supposed to have been 3mm - something must have changed with the last ball bearing changes!)

3. The timing might not have been optimum. A bearing seal (previously mutilated) fell out and ravaged the optics just at the end of the spin-up tests. I had to replace a phototransistor and just guessed at the timing/rotation when I replaced the optics board. Poor timing makes higher currents and less effective force.

4. The light wiring cable to the motor (#10) probably had significant voltage drop.

   What might improve things in a notable way?

1. A thinner air gap between the magnets and coils. That may make considerable improvement. I've heard you can run PMSM motors with quite wide air gaps, but no doubt that really means 1/16th or 1/8th of an inch instead of 5/1000ths, not the 1/4 inch the car moved with. With the new trailer axle hardware for the future models, it will be possible to set the gap very thin without danger of things hitting each other, but a certain amount of gap improves electrical efficiency and prevents the coils from gradually weakening the supermagnets.

2. The computer controls, when they're done, will be set to safely limit the maximum PRM duty cycle at the low RPMs that burn things out, and allow 100% at higher speeds, so the power will increase somewhat with speed.

3. Larger rotors. The rotor diameter provides the leverage radius from the center of the wheel that the magnetic forces push from. Vis: if you have a ten foot pole attached to the wheel, you can easily push the end of the pole to turn the wheel and move the car. With a ten inch pole instead, you may not be able to turn the wheel at all.
   The rotor size is the biggest advantage of the axial flux design - the effective magnetic diameter is almost three times that of a comparable radial flux motor.
   The new rotors for the "production" model are 10-1/4" instead of the prototype's 9-1/2", for about a ten percent torque increase.
   A 12 inch or even larger diameter would provide room for more sets of coils and magnets, acting at again a larger radius from the center of the wheel. I would imagine this variant would be a good size for a heavier vehicle -- or if one perhaps hopes to outfit a smaller car with just two motors instead of four.

4. Electromagnet coils with larger iron cores, eg, 2" round donut cores instead of 1" x 2" almost rectangular ones: three square inches of iron facing the magnets instead of the two of the prototype. With the marginally bigger new rotors there should be enough room. Bigger cores should broaden the magnetic field to the rotor magnets for more torque.
    And one might perhaps deepen the coil cores from 1 to 1.25 or 1.5 inches if it seems useful, to fit even heavier wire (eg #10), for more magnetism with less heat.

   I think the basis for optimum performance lies in these details.

   I didn't like the fact that the transistor had burned a hole right through the circuit board in the 24 volt test. So I started to rethink the layout. Again, why mount these high powered components on a printed circuit board at all? I did it because the original direct wiring was messy with six transistors, and would have been a hodge-podge with 12. I cleared off the old heat sink, dumped some of my new batch of MOSFETs on it, and started looking for an intrinsically neater wiring layout. After some moving things around, and finally bending and chopping leads to better visualize things, I found one. The five heavy leads and connections (battery +, -, and the three phase motor outputs) are short and direct. It's so simple you'd think it was a natural, and indeed once I'd found it it was obvious, but actually it took a lot of puzzling out. The backing insulation is (ready for this?)... tarpaper. Cheap, takes heat, and makes good contact without messy silicone heat conducting grease. How well does it conduct heat? The most I can say so far is that the transistors didn't feel warmer than the heatsink fairly soon after moving the car.
   The new MOSFETs are rated at 60 volts instead of 100 (still 120 amps) and have half the internal ON resistance (.0024 ohms). This means they generate half the heat.

The new rendition of the motor controller power section. This moved the car.

   The motor controller transistors are now doubled up, which should theoretically be good for up to 240 amps and the circuit breaker is 200 amps. But another transistor blowout attempting a test on Halloween indicates the need either to further limit the maximum power at low RPMs or else to at least triple the transistors. (or to stay indoors on Halloween!) Since triple transistors and the same power would probably result in soon blowing the breaker instead, the first choice is probably the better.
   I phoned an old electronics friend on the mainland and I said I was doing a car motor. His first reaction was, "Oh, popping MOSFETs, are you?" It would seem it's a given for this sort of project.
   Things will be eased when there's more than one motor. Then the car should accelerate smoothly with moderate power from each one, instead of painfully starting to roll slowly at full power.
   Also in one recent test, the three black filter capacitors between the wires (photo above) popped, and have been replaced by much heftier units from a motor shop. Across supposedly steady DC lines, the transient spikes from the motor - which are after all what the capacitors are there to filter - must have made enough transient currents to blow the small ones.

   Someone has an interesting idea for an all-electric van: turf the gas engine, transmission et al, and mount the motors on the inner ends of the CV axles. This has all the electromechanical advantages of the direct drive approach, and it would have space for multiple rotors and stators to gain any desired amount of power and torque. In that case, the rotor and stator I made would be one of perhaps two or even three for each wheel, essentially multiple motors on one shaft. (One could perhaps even "stack" multiple rotors and stators with no iron backing except at the end rotors, to make a very light high powered motor: see my Turquoise Energy MPMG generator stacked rotor-stator machine idea on the web at http://www.sears.com/~craig .)

   I'd visited Canadian Tire, Lordco and other auto parts stores many times, and it's very frustrating. You know they have lots of stuff, but it's in boxes in the back, and if you don't give them a make and model of car, they have no way of looking it up, and are mostly unwilling to even open any boxes. I was lucky to find the brake rotors I did for the stator and rotor. Then, in the middle of October, I found Thomcat Trailers in Langford, where there are various axles, hubs, rotors and bearings right there where you can piece things together. After some puzzling with what could work with what, I worked out an excellent looking set of standard parts to make the hubcap motors from.
   A week later I was walking by an auto service center and looked at disk brake rotors in their garbage drums. (dumpster diving for R & D!) There were some four stud rotors that were a virtually perfect size, much better than the ones I'd been buying. They're 10.25" diameter instead of 9.5" (a better fit for the magnets and a bit more leverage radius for the magnetic torque), and the center hub is bigger, in fact a perfect fit for the trailer axles.
   The motors don't need perfect new rotors. The mechanics thought these were probably from a Honda Civic... now we know what to look for at Midas!
   And, seeing some trailer electric brake coils at Thomcat gave me the idea of looking for pre-made electromagnets for the motor instead of having participants wind them during workshops. Though these seemed a good size and shape, the wire was too fine with too many turns. But that started a search for them. A hundred dollars extra for coils is cheap if it saves you from winding your own! I didn't find anything suitable "off the shelf", but it may be that a local motor shop will be able to wind them in quantity for a reasonable price per coil.

   With fine pre-made parts, the motor itself will pretty much bolt together like a mechano set, including securely fixing the entire motor right onto the wheel, dead center, by an axle and bearings. This is a great improvement! As far as mounting the motor, that just leaves fitting the two brackets that bolt to the brake drum housing and come around the wheel, ahead and behind, upper and lower. These meet the arms on the stator, now merely to hold it so it can't spin.
   The other major parts of the installation are mounting the motor controller, driver controls, batteries, and doing the wiring.

Fuzzy Logic

   Somewhere earlier there was some mental lapse in my logic. 100 amps feeding three parallel coils splits into 33 amps per coil, not 100 amps each, where 33 amps through series coils is again 33 amps per coil. Thus, the motor with the coils wired in series should in fact have performed about the same at 108 volts as it now does at 36 volts with parallel coils. Operation-wise, there was no good reason to switch. It should have moved the car about the same. The question is academic first because I never got up past 60 volts (5 batteries), and second because it's changed and I won't go back.
   Safety alone is worth $100 and a few extra pounds of copper in the car for fat low voltage wiring. It's much harder to be electrocuted on a damp day by 36 volts than by 108 or 120 volts, and I expect lots of people to be making and installing their own motors. (I unthinkingly grabbed that 60 volt connection just once to disconnect it. Nothing happened. At a higher voltage, or in the rain, one might not get a second chance.)
   But there's more: the low voltage MOSFETs generate much less heat, and the minimum number of 12 volt batteries needed to drive electrically goes from 9 to 3, an economical figure and a smaller weight and bulk to put into the car. Having even 6 batteries instead of 9 far more than makes up for the extra weight of copper wire.

Electric Hubcap Motor Factoids:

* Two small but powerful hubcap motors supplied with 36 volts should have the power to drive a motor vehicle to city driving speeds (up to 60-70 Km/H or so on level ground) instead of using the car's engine. Four are needed for highway travel and steep hills.
* The motors weigh about 50 pounds each.
* They are very easy to make.
* Most installations are expected to use two or four, even numbers providing for left-right wheel balance and better, balanced, regenerative braking.
* Only the car's wheel turns. The only moving part in the motor is an extended axle that ties the stator firmly to the wheel. Brackets extending around the wheel from behind prevent the stator from spinning.
* The virtually frictionless magnetic link to the wheel magnifies useful power by transmitting it all directly to the wheel. There's no losses from a transmission or gears. It requires no gear shifting or other attention by the driver, and it's quiet.
* Permanent magnet synchronous motors also have the highest intrinsic efficiency of all electric motor families, further leveraging the efficient power transfer. Roughly, one might perhaps expect up to 50% greater range than other (geared induction motor) electric motor systems from the same energy, and correspondingly better performance for the same kilowatts of electricity used by the motor.
* Installation requires no connections with or changes to the car's existing mechanical components and systems.
* When not in use, the motor has no more effect on the car than any other 35 pounds of luggage.
* The motor sticks out just 4" from the wheel or a couple of inches past the fender, less protrusion than the outside rear view mirror.
* The RPM with 13 inch wheels is about 10 per one kilometer per hour of speed, that is, 450 RPM at 45 Km/Hour. Most electric motors prefer much higher speeds, but the "Hubcap" has good low RPM torque and power. 120 Km/hour is just 1200 RPM, a stately pace for most electric motors but a good upper range for the "Hubcap".
* The rotor is a 10 inch steel disk brake disk mounted on the wheel lug bolts, 6 poles using 6, 12 or 18, .5" x 1" x 2" NIB supermagnets, glued and-or bolted on.
* The stator is a similar 10 inch brake disk (but with cooling vanes), with 9 epoxy cast coils bolted to it, each of 60 turns of #14 wire, in 3 phase "Y" configuration. Magnetic flux is axial.
* A unique design breakthrough is that the stator coil iron is strips of regular nail gun finishing nails in the coil cores instead of custom die cut iron laminate sheets. With this and no axle or other moving parts, the motor is simple enough to make at home, or the coils could be wound by machine and cast, for super economical mass production. Individual coils can be easily replaced.
* The motors dissipate their waste heat via air cooling, avoiding the complexity of liquid cooling systems. There's maximal coil air exposure and heat sinking with the magnets blowing air in front of them, an air scoop on the front of the fairing and air guide vanes, plus a temperature actuated electric fan in case all else is insufficient at low motor RPMs that don't move much air and high power (eg, climbing hills and mountains).

Motor Controller Factoids:

* The controller switches the DC power from the battery onto three power wires that go to the motor's stationary magnet coils, in a six state drive sequence timed to continually push/pull the supermagnets on the rotor around in one direction.
* Three optical sensors looking through slots on the rotor tell the controller the rotor magnet positions, to time the switching.
* The amount of torque is controlled by pulse width modulation of the power, proportional to depression of the accelerator pedal beyond "neutral". Reverse torque to slow the motor (regenerative braking) is provided by differently timed pulses proportional to the release of the accelerator pedal above its "neutral point".
* A reverse switch switches the signals to reverse the push on the magnets.
* In accelerating, the motor uses energy from the battery. In decelerating, the motor generates energy, which goes back into the batteries.
* The individual motors and controllers have minimal digital logic and will run connected to controls having nothing more than a 555 timer to generate the PWM signal (connected to the gas pedal) and a forward/reverse switch, though connection to a microcontroller "brain" at the front of the car is needed to provide the more sophisticated features such as dynamic braking.
* The microcontroller chip in the motor controller is the "brains" of the switching system, reading also motor temperature, car speed and direction, and battery voltage.

Turquoise Battery Project
October Gory Details

   I started this project in January knowing no more electrochemistry than most people. But in the endeavor one learns, and I'm gradually catching on and finding some very good ideas and substances.

A Better Positive Electrode Material

   The challenge: the low energy density of nickel oxyhydroxide as a positive electrode limits the energy density of the whole family of Ni-xx rechargeable alkaline batteries. Finding a better oxidizing electrode material seems to need going beyond the simplest reactions and the commonest elements.

   I got enthusiastic about using lanthanum hydroxide as a reducing (negative) electrode, as it wasn't too expensive and had a -2.80 volts potential (or -2.90 depending where you look) and moves 3 electrons per molecule, promising higher voltage and higher amp-hours cells. What I didn't know then was that water starts separating into ions (H+ & OH-) and even into H2 and O2 gas at this voltage level, so you can't use it in a water based electrolyte. About two volts is the effective limit.
   Then I thought I could separate the cell into two halves with a graduated "voltage ramp" (dope the electrode separator sheet with ferric oxide or osmium powder) so the water never sees the whole voltage at any given point, but I finally realized that each half still has to be under two volts. The ramp idea may reduce self-discharge, and may provide the potential for cells up to four volts instead of two, but under two volts on each side. Barring figuring out some strange non-water based electrolyte, the energetic lanthanum hydroxide to lanthanum reduction would seem to be out. :(

   But perhaps the lanthanum could instead be used in an oxidizing (+) electrode.
   I found many of the "rare earths" will form a tetravalent oxide, LxO2, instead of Lx2O3. A lanthanum hydroxide to this "overcharged" oxide should have a good energy.
   But this reaction wasn't listed for lanthanum itself. Another reaction is lanthanum chloride to lanthanum perchlorate, which should have very good energy. Complications arise in that perchlorate is more reactive towards organic substances than inorganics, so some organic catalysts are called for.
   The first battery made up with this, with the sintered monel-lanthanum powder gelled with agar agar in acetal ester solution does seem to charge, but even with all the trouble I've gone to the case has a leak, so the (promising) results are inconclusive so far.
   (Dysprosium should probably be better at oxidizing than lanthanum, but I have the lanthanum.)

The Nickel-Nickel Battery
and Nickel-Calcium Zincate Battery
October Experiments

   In the process of working on the Ni-La battery, I decided to discharge the cell by reversing the polarity. It charged up backwards as La-Ni to over a volt, and supplied some useful current to a load. That's when I started clueing in to lanthanum as a positive electrode - and nickel hydroxide as a negative one. I looked up the reduction reaction of nickel hydroxide and noticed it looked quite similar to cadmium:

      Ni(OH)2 + 2H+ + 2e-  <==>  Ni + 2H2O   [-0.72V]

   This of course complements the nickel oxidation reaction usually used:

     Ni(OH)2 + 2OH-  <==>  NiO(OH) + 2H2O    [+0.52V]

   Total would be 1.24 volts - call it 1.1 volts under load.

   Cadmium [hydroxide] is -0.824V, but cadmium is more expensive than nickel and otherwise objectionable for such a small gain.

   Why, then, had no one made a nickel-nickel battery simply using nickel hydroxide for both electrodes? It would seem an obvious thing to try, but I couldn't find any mention of such a thing on the web, including nothing explaining why it wouldn't work.
   Perhaps companies start with the idea of replacement "AA" and "D" cells, and decided 1.1 volts just didn't quite cut it? Then because it wasn't mentioned anywhere, no one thought of it for big batteries?
   Having the chemicals et al on hand, I decided to try it.
   It started charging fine! But the usual bubbles on my open experiment indicate the cell has to be sealed.

   What would it cost? To make a long list of calculations short, around 150 $/Kg for materials. That's not too much more than for lead-acid, and (probably) would last for ages.

   That was in early October. Then I found calcined zinc oxide! Zinc has a higher voltage than nickel, 1.2v instead of .72, and "calcium zincate" may be even higher. And, it's half the price of nickel hydroxide!
   1.6 volt Nickel-Zinc batteries have been made, but when recharged, the zinc crystals tend to grow through the electrode separator sheet and short out the battery, limiting the cycle life. (This seems to be the usual fate of Ni-Cd's too, in my electronics experience.)
   I can see several ways or potential ways to prevent this, and the calcium may possibly mitigate the process regardless. Worst case, one makes the batteries so they can be dismantled and serviced, eg, replacing the separator sheet with a clean one. This would obviously be impractical for AA cells, but perhaps not for big electric car batteries. But, I don't really expect that none of the possible methods to avoid the problem in the first place will work!

   Even with a nickel positive electrode, the zincate offers better energy density than Ni-MH and Ni-Cd owing to the higher voltage of the reaction, and the cells are still under the two volt ceiling even if the "voltage ramp" should prove ineffective.

   Again, the nickel-zincate battery should be an easy one to make at home.

   Now all we need are leak proof containers. The think I may have the ansswer: I'm going to try stuffing the batteries into small salad dressing or similar bottles, using rubber test tube stoppers to seal the tops. These would have two holes, one for each electrode terminal. The original caps will have the middles cut out and will be screwed back on as compression rings to prevent the stopper from working its way out or popping out under pressure. If the batteries become very pressurized, or if they freeze, the sides will simply bulge out.
   And, they should certainly be cheap! (I can see myself now, digging through blue boxes on the boulevards!)


Craig Carmichael
250 384 2626
Victoria BC