1. Professional DC Electric Powered Leaf Blower
By:
Larry Will
Vice President Engineering
Echo Inc.
Hello everyone. My name is Larry Will. I’m Vice President of Engineering at Echo Incorporated. We manufacture professional quality, gasoline powered, two cycle lawn care products.
I would like to tell you about a program we have been working on that will dramatically reduce exhaust emissions and sound. The concept is a DC electric or battery powered commercial quality leaf blower.
June 22, 2000

2. Design Requirements Safe Zero Emissions Quiet Professional Durable
Portable
Adaptable
Comfortable
Light Weight
Low Vibration
Powerful
Long Running per Charge
Variable Speed
Cost Effective
Before starting this program, we made a list of requirements we felt were essential to the design of such a product.
Being electric, it is important that there be no possible chance of anyone getting a shock or burning themselves. To do this, we have had to develop a smart battery. One that is computer controlled.
The main goal of this project is to eliminate conventional exhaust emissions and reduce sound.
Equally important in our corner of the industry is for this product to be of professional quality and have the same durability as our present products. Our design goal is for this products is to run a minimum of 1000 hours.
As with all hand held products, it must be portable. It cannot be tied to anything as would be the case with alternating current designs.
It must be adaptable or flexible enough to operate many different kinds of tools and at any voltage, including other hand held lawn care products.
It has to be comfortable and light weight. It must be such that it can be worn comfortably all day, without tiring even a person small in stature.
These products have dramatically reduced levels of vibration, making long term tool operation less fatiguing.
A lot of time and effort was spent achieving the power necessary to compete with the gasoline counterpart. It must be greater than one horse power and be able to run at least as long, on a single charge, as one would run on a single tank of gas. The blower will run 40 minutes before needing recharging.
Having the ability to control speed is considered a must. Reducing the speed will reduce airborn dust and current draw, providing more running time on a given charge.
Finally, it must be cost effective. This is the most difficult goal to achieve. Initial investment in tools and batteries will be a great deal more than a comparable gas unit. Batteries will be very expensive and more than one will be needed per operator, if the equipment is run continuously all day long. At a minimum, the professional user will need three batteries, two being charged while the third is being used. It takes longer to recharge a battery than it does to discharge. On the other hand, the power purchased to charge the battery is about 1/10 that of gasoline and oil for the same amount of work done. Over the life cycle of the battery, the cost could be about the same.
February 2, 2000

3. Computer Controlled NiMH Cartridge Battery
Left or Right Hand Application
The battery pack itself is a cartridge which can be easily removed and installed in the carrying frame. This means that the operator can adjust the frame straps to fit perfectly and it need not be readjusted every time a battery is changed. Frames are purchased according to the number of operators you have, not the number of batteries.
The cartridge is reversible. That is, it can be installed with the cord on the left or on the right, depending on operator preference and/or the tool he is using.
Since the battery is computer controlled, the voltage can be varied remotely, which in turn controls the speed. It also controls the charge and discharge rate. Output current is limited, protecting the tools as well as the operator. In the event of failure, it fails to off. Even so, there is a redundant, power limiting fuse, in the event all else fails.
The cartridge has a “fuel level gage” or series of lights, which tells you how much charge is in the battery (1/4, 1/2, 3/4 and full).
The battery consists of NiMH battery cells, providing full voltage virtually until the end of its charge. This means the power and rpm are maintained throughout the discharge period. Lead acid or a car battery, in contrast, starts to lose voltage the minute it begins to discharge. Performance begins to deteriorate from the very first moment the tool is engaged. In many cases, performance is below acceptable limits after only ten minutes, when using lead acid batteries. When we say 40 minutes running time, we mean at full optimum performance.
February 2, 2000

4. Comfortable Carrying Frame
The carrying frame is made of light weight aluminum and fabric in the same basic configuration as a frame used for backpacking. This type of frame is often used by backpackers to carry as much as 40 or 50 pounds. Our battery weighs approximately 20 pounds.
The frame is also designed to stand by itself in the upright position during storage or while the battery cartridge is being replaced.
February 2, 2000

5. Shoulder Straps for Stability
Weight Carried on Hips
When properly adjusted, the weight is carried on the hips, not the shoulders.
Shoulder straps primarily act as stabilizers to the left or right movement of the frame. For comfort, there is also a breast strap to pull the shoulder straps away from the arms, if desired. All strap positions and lengths are adjustable.
February 2, 2000

6. Open Space for Comfort Flexible Power Cable February 2, 2000
The battery is close to the operators back so as not to upset a person’s balance.
Yet, there is an air space between the battery and the operator so the operator remains cool and comfortable in warmer weather.
The power cable is coiled and flexible enough to easily reach the ground when the operator wants to put the tool down to free his hands to do something else. Being coiled keeps the wire out of the way when reaching out in front or to the side.
Flexible Power Cable
February 2, 2000

7. Hand Held Blower 56 dB(A) per ANSI B 175.2 February 2, 2000
The blower essentially draws full power all the time. This tool will run up to 40 minutes continuously on a charge, longer if the rpm is reduced. At full speed, it delivers 135 miles per hour air flow which is adequate for most sidewalk and driveway cleaning applications.
This unit, at full rpm is 56 dB(A). By comparison, our quietest gasoline powered blower is 65 dB(A). Compared to a loud back pack blower running at 74 dB(A), this blower is 8 times quieter.
56 dB(A) per ANSI B 175.2
February 2, 2000

8. Status of Development Preliminary testing complete
Second generation prototype complete
Temporary tooling complete
Market research study complete
Presently field testing
Not released for production
No production tooling
So where is this program?
Preliminary field and laboratory testing is complete.
We have completed our second generation prototype which is presently in field testing.
Temporary or soft tooling has been completed allowing us to manufacture a few hundred units if we so decide.
We have also completed an extensive market research study.
However, we have not finalized the design or released it to production.
No production tooling is available nor has it been ordered.
February 2, 2000

9. Challenges and Concerns
No clear path to market identified
Battery is heavy
Battery cost is high
High tooling cost, small market size
Poor return on investment
Proceeding with this program is not without risk.
There is no clear path to production. Our sales outlet is familiar with selling two cycle engines and have no expertise in the sale or maintenance of electric products.
Battery costs are high. Each battery will retail at about $650 to $700. With there being a need for at least three batteries per operator, the cost becomes prohibitive for most users. One blower and three batteries, for example, could cost the customer as much as $ A comparable hand held gasoline powered blower would be less than $300. On the other hand, there may be some applications, such as at resorts, hospitals, and golf courses, where the significant reduction in noise may justify the high initial expense.
Tooling cost will be high when considering the return on investment. Initially the market, if it exists, will be small, perhaps 2000 units per year. Since we manufacture two cycle engines and not batteries or electric motors, profits could be all but nonexistent.
February 2, 2000

10. Echo Incorporated February 2, 2000
We believe this concept has a future when one considers what happened in the hand tool industry. They started out with a novelty electric screwdriver. A perfect Christmas present. Now you can buy drills, saws and a lot of other professional quality tools. The lesson to be learned ... is that it took several years, perhaps more than ten, to create a market demand great enough to get the cost down to where the price is attractive to the consumer. In our case, a very optimistic sales number would be 10,000 units per year after five years, unless we can achieve parity with gasoline engine costs. This is entirely driven by the cost of the battery.
For several years, GM and Honda have been working to introduce electric automobiles in California. This has clearly been met with limited success.
DC products are clearly good for the environment. For certain applications they can provide excellent performance. Public acceptance and therefore demand, however, simply may not be there. As a company, we are hesitant to spend several million dollars to find out.
February 2, 2000