Here I continue and expand on the Mobility discussion in Chapter 6 of my book, incorporating new research and new ideas. I expect to add diagrams and illustrations in the future. (Rough sketches are all I have now).
Here I will explain a new configuration for a series hybrid electric car that could keep the cost and complexity of converting a car to a small fraction of the cost of a new hybrid electric car.
Hybrid electric cars have low operating costs - for maintenance and fuel, and therefore would be good choices for anyone attempting zero cost living. However as we all know too well, they are expensive, $30,000, $40,000 or more - way beyond the financial means of most folks attempting ZCL. An option that may be practical, if you have some mechanical and electrical ability or can get training or help is to convert a car to electric - and add hybrid capability. Numerous books, web sites, youtube videos, blogs, describe how to convert a car to electric.
Very few specifically go another step and add hybrid capability but it may be as easy as placing a portable generator in the car and plugging it in to the battery pack to keep it charged.
Basic components of a hybrid electric car. (I will not go over the details of conversion to electric here, as stated above, a host of other sources exist for that).
donor car.
generator
batteries
controller
drive train - (here I will present a new configuration).
Donor car: Researching, I found two cars within a few miles of me by typing 'bad motor and 'bad engine' in craigslist . They were priced at $800 and $750 dollars.
Also scrap metal (and used auto parts) companies - such as Regal Recycling in my area - have junk cars available in this price range. (I intend to negotiate for an even lower price as the scrap metal value of cars is about $350). Engine, transmission, radiator and hoses, exhaust, fuel system including tank would be removed and could be sold (craigslist is good for this) recapturing some of the cost.
Generator: Tractor Supply Company sells 13 horsepower generators for only $700 that produce 6kw of electricity (8 horsepower at 750 watts per horsepower).
Batteries: Deep cycle 12 volt may be purchased for $70 each (after discount for bulk purchase) according to the authors of 'Build Your Own Electric Car'.
Controller: needed to control the flow of electricity to the electric motor and thus speed. Though getting cheaper, controllers are expensive and complex.
I have seen controllers advertised on the web for about $500.
A kit exists to build your own, but the kit costs $600. You may end up with a better product than an already built controller with the kit.
A golf cart controller may work - costing only a few hundred dollars or less used.
Fork lift controllers available for even less may work.
The web site 'hydrogenappliances.com' describes a simple method of motor speed control by means of a sliding switch that can connect one, two, three and more batteries as needed to add power and speed. As the batteries may be used unevenly in this design electric car builders generally avoid this kind of controller. But dealing with the charging problem may be cheaper and easier than designing, building or buying a complex expensive controller.
Drive Train: Here (at last) is the core idea of this discussion.
Here is how a series hybrid electric might be configured to reduce cost, weight, and complexity:
1. Onboard modest generator as describe above: $700 6,000 watt.
2. Modest number of batteries possibly as few as 6 batteries 12 volts each for 72 volts total.
3. Both are hooked up to the electric drive motor and are able to provide power to the motor simultaneously. The generator also keeps the battery pack charged up, feeding energy to the battery pack when excess electricity - not needed for the electric motor at the moment - is available. No large bank of batteries is needed, and the I.C.E. ('internal combustion engine' driving the generator) is the modest, simple and efficient generator engine that always runs at a single constant speed. A simple single speed carburetor designed to run the engine at optimal efficiency is all that is needed. No complex carburetor, computer, or transmission is required.
Increases in energy demand - for accelerating - are handled by the battery pack.
More energy is needed during acceleration. Once acceleration ceases, and a constant speed is attained, energy need is reduced (compared to acceleration).
When accelerating, both batteries and generator feed energy to the electric motor. When higher speed is attained, the electric motor may not need all of the energy available from the generator and excess energy from the generator is used to charge the batteries back up. When decelerating, or moving at slower speed, or at a stop, the generator will have excess energy available and can continue to charge the batteries until they are fully charged. The generator can shut down if no energy is needed by the batteries or the electric motor. For a while the car can run on pure electricity - as in stop and go traffic or on slow city or rural streets. When power demand increases - to accelerate and/or travel at higher speeds the generator i.c.e can be turned on again.
In this power train configuration, the generator may run most of the time when higher speeds (40 miles per hour or more estimated) and acceleration are needed - either to keep the small battery pack charged or to add power to the drive motor during acceleration.
For short distances at slow speed batteries alone may be all that is necessary, saving on the gas wasting use that conventional cars suffer from running their motors while they creep along (as in a traffic jam), or on city side streets with frequent stop signs and lights, or on rural dirt roads where speeds are usually 25 miles per hour.
Because the generator engine is small and constant speed it can be light weight and efficient, keeping vehicle weight low and at the same time making unnecessary a large heavy battery pack - no mass of lead to lug around or expensive high-tech battery pack to buy. Plus, fewer batteries are needed when the time for replacement arrives.
A further money saving improvement. Use two modest electric motors 8 horsepower each costing $700 each rather than a larger expensive motor costing $3000. Electric diesel trains use two electric motors. They 'gang' them when needing more power. As in trains, these two cheap electric motors may be 'ganged' when more power is needed for greater speed. Permanent magnet motors are technically simpler, cheaper, and more durable than other types and may work best in this scheme.
Other savings:
Properly designed, an electric car could get by without a transmission - though most conversions use the manual transmission on the donor car. (they don't buy donor cars with automatic transmissions). The ganged electric motors may be linked to the drive wheels by means of one or more drive belts - cheap simple, and easy to replace (if designed correctly).
Summary: adding all the costs up above:
$ 700 donor car
$ 700 generator
$ 360 six 12 volt batteries
$ 500 motor controller
$ 20 drive belts
$ 1200 two electric motors and mounts.
$ 3500 total
Further discussion:
weight: This configuration keeps weight down. Possibly 2,000 pounds total (vs 3,000 pounds or more for most electric cars). Less weight means less energy needed to move the vehicle and greater speed and range.
miles per gallon: keeping weight low improves mileage. The battery mass of conventional electric cars reduces their range and mileage I would aim for 50 to 60 miles per gallon in this car.
range: Because the on board i.c.e generator engine is fueled with gasoline, range can be as great as any conventional gas powered car. At 60 miles per gallon and an 8 gallon fuel tank on board range could be 480 miles.
initial build and servicing: all components in this configuration may be small, compact and widely spread out: motors, batteries, generator. They all may be installed by hand with hand tools, making initial conversion easy and making later servicing easy. Components may be easy to swap out so a major repair may take only a few minutes. For example, a failed generator (if designed for it) could be removed and replaced in minutes, the failed generator left at the repair shop (or repair garage at the home of a handyperson/ZCL practitioner who can fix his/her own engine). If the generator is easy to remove, it can be easy to access and service - not buried in the car as is the case with conventional I.C.E. front wheel drive cars.
safety: components: batteries, generator, drive motors may be distributed around the outside of the passenger compartment to form and reinforce a 'crush zone' protecting passengers in an accident.
Also, large, heavy battery packs may be dangerous in an accident, flung around like missiles, possibly breaking through firewalls or hitting passengers or vital components, or spewing acid or grounding out to the frame causing sparks and fires or shocks to passenger. Fewer batteries means less of a problem - and each individual battery may be better secured - compared to a heavy battery pack.
The modest onboard generator may have a small fuel tank and less fuel, less dangerous than the large fuel tanks in conventional cars.
reliability: electric motors have tremendous reliability, able to run trouble free and almost maintenance free for thousand of hours. Repair or maintenance may be easy to do. They have few, or even one moving part so there is little to wear or go wrong. Problems are easy to identify and easy to fix.
Restatement: The reason this concept works is because large energy demand, and a lot of horsepower is only needed for acceleration. At freeway cruising speed and in normal slower speed driving energy demand is less - often well under 8 horsepower - so this is the base horsepower needed. 100 horsepower, 200 horsepower or more used in conventional cars are a gigantic waste of energy most of the time. A battery pack can take care of acceleration loads, allowing a light, cheap, simple engine to only large enough to keep up with the normal cruising energy needs of an automobile.
