The Hybrid Automobile

and the

Future of Amateur Mobile Operation

I don't know how many amateurs operate mobile, but I'd suspect the number is rather large. The majority operate VHF of course, with a much smaller number on the HF bands. It really doesn't matter which mode or frequency, as all require some amount of current at a nominal 13.6 VDC (although we refer to is as 12 volts). Amperage requirements vary from an amp or two, to as much as 100 amps peak. All of this power is usually supplied by an alternator with the SLI (Starting, Lights, Ignition) battery acting as a buffer. In some installations, there are two or more batteries, and a larger alternator delivering as much as 250 amps. Twelve volts is twelve volts, and if you use good practices, installing mobile equipment is not difficult. I do my best to explain the correct procedures in the various articles on my web site.

I've been operating amateur mobile for many years, and I've seen the change from 6 volt to 12 volt systems; the latter is now so ubiquitous we don't even consider it when buying, or installing a mobile transceiver. Good, bad, or indifferent, there is a change in the wind.

The current gasoline prices notwithstanding, the future has been written on the wall for many years; we have to reduce our dependency on fossil fuels, foreign or otherwise. The EPA, for what it is or isn't, has set standards for fuel mileage and emissions we all must meet. The automobile manufacturers have stepped up to the plate, and given us all manner of technical wizardry to improve mileage, and reduce emissions. Some of these new devices exacerbate the RFI we contend with. One of these, COP (Coil Over Plug), has become the number one bane of HF SSB operation. Unfortunately, there are more insidious demons creeping into our beloved mobile sanctuary. Enter the Hybrid automobile!

I am not an expert on hybrid systems by any stretch of imagination. If you are, great! I wish I had talked with you before I wrote this article. So please, don't get offended, and pick at the details. After all, this is supposed to be generic information. For those who wish to learn more, there are hundreds of web sites dedicated to this new technology.

If you're thinking about buying a hybrid vehicle, read all of the data on the particular model you can, as some of the data is purposely misleading no matter the manufacturer! This includes, but is not limited to, the application of included warranties, extended warranties, and assumed warranties especially with respect to the requisite assist batteries all hybrids require. While this may sound off the subject, it isn't. In a recent California Supreme Court decision, it was ruled that extended warranties cannot be considered an assumed warranty. By all means, read the fine print carefully, and ask questions even if the wording appears non misleading. Caveat Emptor!

In the future, we may see fuel cell, hydrogen fueled, and perhaps 200+ mile-range full battery vehicles in our driveways. Until then, the main thrust is the battery assisted gasoline vehicle better known by the name hybrid. There are others looming on the horizon, but currently available hybrids are mostly from Honda, Toyota, and Ford, with a few from secondary market suppliers.

There are so many different configurations, it is hard to make a pat statement about any of them. What follows is an overview, and is not specific to any particular vehicle. Each manufacturer is slightly different in their application. If there is one commonality, it is the type of assist battery they employ. Currently, almost without exception, hybrids use Nickel Metal-Hydride (Ni-MH) batteries.

Similar to lead-acid SLI batteries, Ni-MH units are designed to provide copious amounts of power for a short duration, and can be charged at very high rates, with some in excess of 100 amps at 128 volts! Other than the specific battery technology, the main difference is their nominal voltage. An SLI battery may be from 12.2 to about 13.4 volts (slightly more under charge), the typical hybrid battery delivers 120 volts to as much as 750 volts. There are several reasons for the high voltage, not the least of which is an effort to reduce I²R losses, and the available current ratings of the requisite solid state devices needed to control all of the complex functions.

Complexity is the key word here. The average hybrid has a small gasoline engine which uses modified valve timing to emulate the Atkinson cycle design rather than the more conventional Otto cycle design. Between the engine and transmission is a brushless, permanent magnet DC generator which (in most cases) can be used as a starter motor. There is the Ni-MH assist battery, a brushless permanent magnet DC drive motor-generator usually called the assist motor, and the all-important electronic control assembly. In some cases, there are multi-farad capacitor banks (16 to 64 Farads!). I could go into a long dissertation on the variances in designs, which energy saving algorithm they use etc., but there is so much information available on the net, the effort would be superfluous. Besides, this is suppose to be an amateur radio related article.

The rub comes for us amateurs in the methodology any specific design uses. Almost all use a standard (albeit a little larger in size) SLI battery to supply power for the lights and accessories while the engine is shut down. In some models, like the Honda accord, it is also used for starting if the assist battery is low. In most cases, the SLI battery is charged using the generator, not the alternator. Since the main function of the generator is to charge the assist battery and/or power the vehicle by supplying power to the assist motor, the amount of energy available to charge the SLI and/or power amateur radio equipment remains to be seen.

After spending about 10 hours reading about the various hybrids, and sending a dozen or so e-mails to the manufacturers, I've drawn a blank with respect to the charging current supplied by the generator (I think it is a trade secret). The Honda Accord does have an alternator, but most hybrids do not. One could assume it would have to be as big or bigger than that supplied by a standard alternator (100 to 160 amps), but there is no published data I can find to support the assumption. This fact begs the question about how much additional amperage is available, if any. While I cover alternator reserves on my web site, until such information is available for hybrids, we're in the lurch. One fear I have is that high power mobile may become a thing of the past.

There is another aspect too. What about all of those high-tech controllers? Are they compatible with amateur radio, and if they are at what frequencies? I do not believe there is enough information disseminated from the manufacturers and/or users to even make a WAG.

My brother Evan, K0HYG (sk), ran a 100 watt Yaesu, and an ATAS 120 antenna in his Toyota Prius without any apparent problems. He never used the radio except on highway trips where the engine runs constantly. I recently spoke to an amateur in Georgia who was using a Honda Civic hybrid, and an Icom 706. His only comment was the excessive ignition noise while the engine was running. With respect to egress RFI from the various parts, until hybrids become common place, our current view may be distorted. Fixing any egressed RFI may end up being a dangerous undertaking. The 128 volts the Toyota uses, to the nearly 750 volt system used by ISE, there is a new level of concern not only for our use, but crash responders as well.

There are a couple of other technologies on the horizon we need to think about too. One of those is the 48 volt system. Several GM models are slated to have 48 volt systems as early as 2007. While they are supposed to have 12 V accessory outlets to run existing devices like cell phones, the available amperage is too low for even a moderate amateur radio power level.

Pure battery vehicles may be a ways off, but undoubtedly they will use higher voltages than we are used to. Further, it is certain that accessory devices will become available to run off of what ever voltage level becomes standard (if any). We certainly don't have to worry about Icom, Yaesu, Kenwood, and others as they will supply whatever equipment is necessary to preserve sales. This primarily because their thrust is commercial, not amateur; we're just along for the ride.

Not everything is dank and dark. If GM does introduce a 48 volt system, assuming it will not be a hybrid, the nominal 54 VDC output will make high power mobile much easier to accomplish. In fact, this is a high enough voltage to easily allow 1,000 watts out if the alternator proves to be sufficient. As a side light, think of all of the new light bulbs, head lamps, and instrumentation this changeover will cause. Maybe it's time to invest in General Electric, as they make both assist motors and light bulbs.

Nonetheless, I'm looking forward to the first articles to appear in the pages of QST describing switching converters to supply 13.6 VDC from a 128 or higher voltage assist batteries to power our transceivers, and other goodies. Heck if they can supply 12kW or more energy to an assist motor, surely they can power an Icom IC-7000 via a converter.

No matter your feelings in this matter, hybrids, fuel cells, hydrogen, and new battery technology are happening now, and the sooner we start thinking about their impact on our mobile operation, the better we'll be equipped to meet the challenges.

Alan Applegate, K0BG