We built our high mountain cabin on ground covered with volcanic ash.  At the time, my wife and I wondered how long it would take for nature to hide the evidence of the latest eruption of Mt St Helens. That was 1980 and our cabin has undergone many changes since then. Come to think of it, so have we. As we grow older; we seem to be attracted to some of the luxury items; like electric lights,  an indoor shower; and although the satellite dish is not a must, it's nice to connect with the rest of the world from such a remote place. This all becomes possible with a modified sine wave inverter,  I bought a unit from donrowe.com, it really runs everything we need at the cabin, and then some. And most important, it's quiet, why go where it's quiet only to make noise with a generator?

All these comfort items triggered the need for a better way to charge batteries. We have a little Coleman generator designed for light duty;  with a 10 amp 12 volt charger built in; but one quickly learns that 10 amps isn't much for charging batteries if you're running a 19 inch TV, direct TV receiver, compact fluorescent lights, water pump, and other miscellaneous loads. Sure; you can buy a battery charger and power it via the AC outlet, but is there a better way?

My home made gas powered charger is based on a military generator with a bad Gen Head, I saved the frame and the engine, the parts I added were painted Army Green, and some might think it came this way! 

After mounting a cheap aluminum 6 inch 'A' type pulley to the crank, I welded a bracket up for the auto alternator and found a small belt to fit the need. I hooked the unit to a junk battery and noted 75 amps of charge rate. If my basic math holds up, that means I could deliver the same charge to the batteries in 4 minutes versus 30 minutes it would take with the Coleman charger, WOW, that's what I call noise reduction if nothing else. I made up some leads and decided to haul this charger up to the cabin next trip.

It was Elk hunting season, three of us packed up for a 10 day hunt out of the cabin. The Gen. set got thrown into the utility trailer and buried with supplies. When we arrived, we set up two deep cycle batteries outside and dropped the Gen set a few feet from the batteries. One evening; we were watching a movie and the inverter sounded it's alarm; "low voltage!", "feed me or I'm going to dump your Dish programming!". I grabbed the flashlight and went out into the night to start the Gen. set. Where's the rope? I hadn't returned it to it's place, I shined the flashlight around looking everywhere. The wind was cold and blowing about 25mph, I could see snow flakes in the beam of the flashlight. I found the spare starter rope and wrapped it around the pulley, six pulls later the set was running and I bolted for the door. I quickly claimed the seat next to the wood stove and caught up with the movie.  In the back of my mind, I was planning the next enhancements to the charger, "going out in the middle of the night to crank up a cold Gen Set is not  my idea of fun".

In the photo above, you can see one of the added components, (a starter motor).

Just as important are the changes made in the stock circuit breaker and control cabinet. The black box stuffed in the corner houses the Stamp micro controller. When the batteries discharge to a  threshold defined in software, the Gen Set comes to life, the 'Monitor' software module passes control to the 'Start' module, when it's completed the task of starting the engine; it passes control to the 'Run' module, etc. The processor gets most of it's data through two dedicated Analog/Digital Converters (ADCs). With these inputs, the software can do a fair job of monitoring the power plant. Other benefits of the controller are logged runtime totals, logging of battery readings, error logs, and other things that can help you keep track of maintenance requirements and the performance of your batteries. There is also extra I/O for adding features including a serial port that allows the controller to pass on status and data to other intelligent devices.

I have learned a great deal constructing this Gen Set, first off, don't use cheap pulleys! Cast iron works well  for an application of this type. Another thing I learned... properly designed electronics are reliable,  getting the mechanicals right was the biggest problem for me. Take care in alignment of pulleys; designing good belt tension adjusters, and that sort of thing. As for software, how nice it is to write changes versus redoing hardware, and it's far easier than you might think.

The starter motor is a 12 volt permanent magnet design used in a city transit bus as a cooling fan motor. It is rated at 3/8 HP at 2800 rpms as a motor and delivers around 35 volts at governor speed in this application. I found the output could be used to arc weld; using Wall Mart 6013 5/64th rod; it does a great job on 1/8 steel, move to a smaller rod, and you can easily get enough penetration to weld much thicker material.  Most important, it spins this engine to a start every time.

According to what I've read,  car alternators are inefficient devices, a typical auto alternator is about 50% efficient. This isn't a big thing for this application, but if you were looking to get your monies worth out of a gallon of fuel, you would NOT build around a stock automotive alternator. There are better ways to get the job done, I am working on a small fully automated diesel charger with a highly efficient generator section, look for it on the 'projects page'.  

Following... pictures of the country around the cabin:

Tampico, WA. is the closest gas stop, although they only have one pump, they have a parade each spring and fall.

Louie Way Gap, 'not far from the cabin' ; that little bump in the back ground is one of our volcanos... Mt. Rainier, and that little puddle of water in Rimrock Lake.

Mountain Sky

The addition goes on.

8/23/02 I'm planning an all out 'Off grid' power system for the Mountian Cabin, take a look.

George B.