Low Power halogen lighting for RV boondocking use
Dave and Helen Damouth www.damouth.com
revised October 24, 2000
I recently bought one each of several different types of low-power halogen fixtures, for evaluation in our travel trailer. I've now installed them all and Helen and I have lived with them long enough to give you a report. Except as noted below, these are all from West Marine. I bought them in the San Francisco store, but they are also available from the catalog (pages 538-540) or, I presume, from any of their other many retail stores. 800-262-8464. Several other styles are available, in addition to those I list below. All have a built-in off/on switch, and must be wired directly to your 12v. power except as noted below. The bulb prices are not quite as ridiculous as they sound, because they should last considerably longer than conventional bulbs. Also, these bulbs retain nearly constant brightness until they die, where bulbs like the 1141 get quite a lot dimmer as they age.
a: #129421 white, 2-way swivel base $24.95. This is inexpensive and very convenient to use. It uses a 10-watt projector-style bulb (like a miniature automotive sealed-beam headlight, or a modern slide projector bulb. The bulb is expensive ($10.49), but otherwise, this would probably be our favorite 10-watt reading light over the sofa or bed. It has a very narrow bright, white, beam. I have it mounted on the side wall at the end of our sofa, roughly 2.5' from the normal reading position of a book. It provides *much more* illumination on the book than the original 36 watt fixture (two #1141 bulbs), and the bright spot of the beam nicely spreads across a book. The other side of the coin, of course, is that it illuminates *only* the book it is pointed at, leaving the rest of the room quite dark.
Note added 10/24/00: The above fixture is now also available through Backwoods Solar for $18. Replacement bulbs are $9. Some of the fixtures listed below may no longer be available from West Marine - check the current catalog. I've also noted that some of the West Marine stores are smaller than others, and carry a much more limited selection of the products listed in their catalog. Another low-power light fixture worth trying is also in the Backwoods Solar catalog, part # L-ELF, in white, black, or green. This is a 13 watt compact flourescent bulb in a parabolic reflector, with a swivel mount that can be tilted and locked in any position. Probably the best low-power lamp for illuminating an entire desk top. I haven't tried one yet, but intend to soon.
b: #217943, in black, brown, or white, $37.99. Brand is AquaSignal. Made in Europe, and a typical Euro-modern streamlined, almost spherical, plastic blob. The light head had a clever mechanism to allow it to rotate and tilt over a wide range. It uses a 5-watt bulb which costs $5.99. I have this mounted over my bed, replacing an 18 watt incandescent fixture. It is about 2' from my normal reading position, and spreads nicely across the book page. It is substantially brighter than the fixture it replaces, at less than 1/3 the power.
c: #548115. Hella - again European. This is a small reflector head on a 10 1/2 " long flexible stalk, all black. $39.99. Also available with a 24" stalk for $49.99 (#192064). Spare bulb is $5.99. 5 watts. This has a beaded plastic lens which spread the light a bit more than some of the other fixtures. We have mounted it to the underside of the cabinets over our dinette table. The mounting surface is 30" over the table surface. It works well for reading, although not quite as focused as (b) or (a), and hence not as bright on a book. The stalk lets it be bent toward either side of the table, and extends out almost to the center of the table, nice for spreading out a newspaper or jigsaw puzzle on the table. The soft, somewhat diffused light is nice for an after-dark dinner - not yellow like a candle, but some of the same effect. A pair of these, mounted near each side of the table, might be nice. If it is primarily a reading light, it should ideally be mounted so as to position the light source about a foot from the book. With this in mind, the 24" stalk would be a better choice, allowing the light to be positioned close to your book for bright reading, or high above the table for soft, uniform illumination of the entire table.
d: #582017 (on an 11" stalk, $29.99) or #582025 (same head, on a short swivel $24.99). black, 5 watt. ALFA brand. Based on the catalog picture and description, these sound great. They weren't in stock in the store I visited, so I haven't evaluated them. The bulbs are $2.75 - much cheaper than for the other fixtures. The fixtures are rated for bulbs up to 30 watts if you want more light. The on/off switch, on the base, has a tiny red LED showing the position of the switch, so you don't have to grope around in the dark hunting for it. I need to buy a few more fixtures, and I'll probably get these.
e: Littlelite: This is L-LTL3 in the 1987 Backwoods Solar Electric catalog (swilley@nidlink.com) $34. I bought it a year ago, and have had it installed for quite a while. It has an 18" gooseneck stalk, a small wall-mount base, and a dimmer in the base. black, 5 watts. Replacement bulb, $5. A weighted portable "desk lamp" base is available for $9. The long stalk makes it convenient to position near a book - and you do have to position it within a foot or so of the book, because the reflector is smaller and not as well focused as some of the other lamps above. I have this one mounted over my computer desk, which is also my favorite reading position. It does the job, and the dimmer is nice, but if I were doing it again, I'd probably try (c) or (d) for this application and give up on the dimmer. One reason is that the reflector is so small that when positioned in the best position for my reading, it also shines a small but annoying amount of light into my wife's eyes, on the sofa across the room.
f: Sort of home-made: It is a 2" diameter, 3/4" thick, reflector fixture intended to be mounted under kitchen cabinets I've had this one in use for about a year. Bulbs are 10 watt. Several of these fixtures, plus some wire and a 120v. to 12v. transformer come as a kit, typically in home-improvement stores. I mounted this fixture on the end of about a foot of #12 solid copper wire, and screwed the other end of the wire firmly to a cabinet bottom above one side of the dinette table. I mounted a little off/on toggle switch in the cabinet base. The heavy copper wire is flexible enough to function as a gooseneck to allow pointing the light at my book, or at a table top, and rigid enough to remain positioned where I point it. This looks a little weird, but works very well. The reflector is not quite as well focused as some of the newer fixtures, having a central hot spot which is good for reading, and a broader peripheral area of somewhat less intense light. I probably won't install any more of these - I like the new ones better.
g: There is also another, even more expensive, alternative that is far more efficient. Real Goods (I had a 1987 catalog) sells a cluster of LED's, of various colors blended to look white, mounted in a base that can will fit a standard light socket. These are claimed to be bright enough to use as a reading light, and to be extremely efficient. They last almost forever. I keep intending to order one to try, but haven't yet done so. I no longer have a Real Goods catalog, so perhaps someone else can look it up and provide more information, and a phone number or web address.
For comparison to the above fixtures, the often-used 1141 bulb is rated at 18 watts. (The data I presented in an earlier message suggested that the power was more like 16 watts when running from a 12v. battery. I now realize that these were somewhat old bulbs whose power had dropped with age). The original fixtures in our trailer - at each end of the sofa and over the dinette, each have two of these bulbs, and thus are 36 watts each.
As a result of installing the new halogen fixtures, our typical power usage when the two of us are reading after dark, has dropped from 54 or 72 watts (depending on where we are sitting) to 10 or 15 watts (again depending on where we are sitting, since we have a mix of 5w. and 10w. fixtures.
In the course of a five-hour dark winter evening, this is a savings of 15 to 25 amphours - which could cut our typical daily usage in half. Given many days of heavy clouds, this would extend our battery life from three days to a week or more. With light cloud cover, or a couple of hours a day of full sun, it could make enough difference to allow us to keep the batteries fully charged.
So I'm pleased. By the time I'm finished (still have to order a few more fixtures) I'll have spent about $200 on new light fixtures, and it feels to me like money (and several hours of my time for installation) well spent. We have not just less power usage, but also better reading light than we had before, and we are finding that we use the new fixtures most of the time, not just when boondocking. Older eyes do need more light. We left the old fixtures in place, for those times when we are on shore power and want a more diffuse, general, light.
I should also note that we will continue to use fluorescent lighting over the kitchen counters and in the bathroom, where we want to light a broad area. Fluorescent light is several times more efficient than incandescent or halogen bulbs, but can't be focused on a small area.