I purchased this for trickle charging the battery on my tractor. It tends to sit (covered) in a sunny spot, and, it is an electricity hog when I use the lights on it. It has worked well for about a month maintaining the charge on the battery, making up for the poor output of the old generator on the tractor, and boosting the starting and lighting power.
This unit provides a constance 0.15 amp charge. I have a few concerns. I hooked up a high quality voltmeter to it and the charge read somewhere between 16 volts and 18 volts (off the scale on my volt meter). Under a load (once connected to the battery) it may read a lower voltage but I have not measured it under load.
My other concern is that this does not have any kind of voltage regulator. When your battery reaches its full charge there is a possibility of overcharging the battery.
In any event, it charges a battery over a period of about four days and keeps it charged.
A real plus to this unit is that it is accompanied by an excellent array of leads. It has an extension cord that is about 8 feet long. There are four types of leads enclosed with the package.
The first are bare wires (+ and – (red & black)) that, on the other end, plug into the unit or the extension cord.
The second are a set of alligator clips (+ and – (red & black)) that, on the other end, plug into the unit or the extension cord.
The third is a male cigar lighter adapter that plugs into the unit or the extension cord.
The fourth is a female cigar lighter adapter that plugs into the unit or the extension cord.
All of the connections and leads are of good to high quality.
With these attachments, you have the versatility you need to hook it up to any vehicle or 12v battery.
This is well worth the $50 (approximate cost plus shipping).
One of the best ways to learn about alternative renewable energy is to make sure that grade school and high school students are aware of it. While talking about it in theory is nice, the best way of teaching them is for them to see samples of alternative and renewable energy products. Perhaps taking a trip to a wind turbine site could be arranged. This visit is a good reason for students to see how renewable energy is at work. There is also a better option: having one product in your classroom. Purchasing used solar panels are inexpensive these days. Some of them can cost as low as ten dollars, motor converter included. There are websites that sell such devices which feature the cell panel and the motor to convert the solar energy. These items can be touched, felt, and perhaps even experimented upon by students. What used to be the realm of college engineering undergraduates can now be available to grade school students. Seeing solar panels work and understanding its process may even provide that spark for them to improve on such products. For as long as these students are exposed to such equipment, the possibilities are endless.
Its part of a teaching method called guided discovery wherein students are encouraged to learn through their own means about certain concepts, aided by equipment that illustrates or provides an example of such an idea. This is so true especially with scientific items. And for alternative renewable energy, getting a used solar panel, albeit a miniature one is a great and simple investment that will pay off in dividends down the road. Think of it like automotive class, it's easier for people in that class to understand how cars work by working on cars. The mechanical side of their minds takes over and they see the process not in a concept or theoretical form, but in its practical and a working model of it.
Geothermal energy, and its concept, can also be seen in the form of volcanoes, a stipend of science projects in the days gone by. The ability to harness that energy from the steam produced can also be contained and transferred to a unit that can distribute such energy. The same goes for tidal energy, hydro energy, and wind turbine energy. The issue is always the containment of such displaced and stored energy and its transfer and or distribution. By exposing our children to such scientific and engineering processes, perhaps one day, they will come up with the great energy solution. But for now, all we can do is to encourage them.
Cory Wagner