Tag Archives: Off grid

The Truck!

Ah yes … The truck.


First outing with the new array.

A 1995 Mitsubishi Fuso FH100, and I, the original owner,

What a machine!

The FH100 was a left over model the local dealer “found” sitting on a dock in Florida waiting for something to do … And did I have something for it to do!

I had had the pleasure of working with John Minnehan and his company “the Ultimate Video show” bringing a high tech video night club to lots of college campuses that were … Let’s just say … Off the beaten path!

Lots of miles … Lots of heavy gear … And lots of hours listening to some of the hottest dance music the 90’s had to offer … I am still in recovery!

But the truck was amazing at it. With a GVW (Gross Vehicle Weight) of over 17,000 pounds and weighing in at under 9,000 pounds empty the amount of gear it could handle was beyond belief … It surprised a lot of weigh station officials over the years … The sad look that would cross the faces of the DOT guys as they opened the door and read the GVW tag was always priceless!

But I digress …

The truck seems to have been built for my solar project. With it’s small size and super heavy duty frame, brakes, suspension and cargo restraining system moving a bunch of batteries around with the truck was going to be the easy part.

I wanted to find a better way to solar recharge the batteries between shows, and with business picking up I started looking up. With 120 square feet of flat roof on the truck, adding solar panels to the “attic” seemed like a good idea. If I could find a way to permanently mount an array on the truck I was going to save a lot of time and trouble moving batteries around.

I wanted to have the panels “rail mounted” flat above the box of the truck … With the rail system designed to protect the panels and any low hanging tree branches from each other!


The rail mounting system

I was curious as to how well the panels would work laying flat … (Instead of being angled at the sun) … But was pretty certain after 2013’s experiment that I would be able to recharge the batteries … I was just not sure how much the process would speed up, or how much power I would get … Never mind what, if anything was going to happen on those short winter days with the sun low on the horizon.

Time would tell.

While the truck was being worked on I went through and rebuilt the charging station I had made for the project back in 2013, tidying things up a bit, adding a web monitor and a wireless router to connect the rig to my I-phone and maybe someday even the world!image

I think I’ll need to rent a teenager to get that far … Any leads on finding one would be greatly appreciated!


The new array! Four Sun Tech 235 watt panels.

I got the truck back from the shop with the four solar panels installed on July 3, 2015 and spent the next two days adding the electronics and cabling … Personally drilling two holes in the truck roof for the “glands” that the cables were going to run through seemed really wrong … But the glands, and the silicone sealant that were used have kept everything nice and dry.

The next day I got up before sunrise and made it down to the truck as the sun was clearing the trees on the horizon and found I had already harvested .194 kWh of power … Before the sun had even hit the panels!



Rise and shine … Time to get to work!


“Old Guy” taking a “screen shot”, 7/6/2015

The readings I took from the web monitor at the end of the day showed that the charger went into “float” stage around noon … With a total harvest for the day of 1.41 kWh of power … I was not really sure what that meant … But I was impressed!

As I sit here on a Sunday morning in late January, with six months of learning “under my belt” I am still impressed!

As for the short days of winter … Yesterday, a sunny January 30, 2016 the Sirus Solar DS-201 web monitor showed I had put 143.7 amp hours of power back into my 12 volt battery bank … 1.72 kWh of power … Not bad for four 235 watt solar panels laying flat on a winter day in New England … Not bad at all!


Screen shot from 1/30/2016



2013 was looking to be pretty exciting with the St. Patricks Day parade and the Easter sunrise service working so well … Though I was a little behind schedule with my plans to get meters installed and upgrading the wiring on all of the battery systems.

The rest of the parts had arrived … Finding time to install them was another story.

More shows, putting another battery system together and getting the meters installed in three of the systems kept me very busy through June … And I was starting to get some data that seemed to make a lot more sense … But I still had lots to learn.

One of the battery banks with the TRIMETRIC 2025 battery meter installed.

One of the battery banks with the TRIMETRIC 2025 battery meter installed.

I was planning on using the 2013 Elma Lewis Playhouse in the Park series to test how feasible the project really was. I had hoped to solar recharge all of the batteries between the weekly shows this year … And had ordered an MPPT (Maximum Power Point Tracking) solar charge controller to do it with … After doing a little math it seemed like my three 120 watt solar panels would be able to capture enough sunlight to recharge all the batteries during the week … Even allowing for a 50% operating efficiency … Something I hoped would be a conservative estimate … Especially with rain and clouds being a fairly common occurrence here in the Boston area.

My initial plan of setting up the solar panels and batteries on site for the series turned out to be a little naive … I had to scramble a little to get a “Plan C” up and running … My truck would be parked from Wednesday night until Monday afternoon and with a little help and a couple of tall ladders the solar “array” would be strapped to the top of my truck, the charge controller hooked up… And … Time would tell.


PS … It worked great!

Back to the drawing board!

Oh well … It turns out almost everything I did on my first attempt at going solar was wrong.

Wrong wire sizes, wrong lengths, wrong assumptions about how a bank of batteries should be wired … All of which made for a lot of possible failures.

Overestimating how much power I would actually be using … And more than a little good luck keeping any of those failures from happening!

So … Back to the drawing board …

The first “order of business” was to get a real metering system installed … It was time to find out what was really going on with the batteries.

I needed a “gas gauge” I could trust.

The Trimetric meters from Bogart Engineering are highly recommended by a lot of folks. … I decided to try the 2025 RV model for the project.

The 2025 is a very neat device that keeps track of the power in Amps  going in to and out of the batteries … A quick look will tell you the voltage. Press a button and you will see how much power is going into or out of the batteries. Press the button again and the meter will tell you the batteries are 87% full (… Or 18% full … It might be time to start thinking about worrying … Soon!).

In any case … More information than I could have hoped for!

The folks from Bogart Engineering have designed the meters to do a lot more … But those three things were going to answer a lot of my questions … And keep me out of trouble … For a little while at least!

Adding the meters to my “rigs” was going to take some rewiring … and some math … More on that later.

Since I was going to have to get in and do some rewiring to install the meters it made sense to go in and fix as many of my wiring mistakes as possible … My good luck was only going to get me so far!

If  you’ve been following along since the beginning you may remember my first big battery powered show having some yellow “warning” LEDs flashing on one of the inverters. The band had not gotten any louder … But something had changed … It took over a year to figure out what had happened … the power in the batteries was not getting to the inverter.

Resistance was “robbing” the system of power.

The wire I was using was too small and too long for the current that was trying to get from the batteries to the inverter … Causing a voltage drop … Causing the inverter to “ask for more power from the batteries … Causing the resistance to go up …causing more voltage drop … Causing …

It was a good thing I pulled the amplifier from one inverter and plugged it into the other inverter when I did … Or that show might have been the last!

My common sense approach was not helping at all … Luck … On the other hand … Was!

When using batteries to power something you do not want to waste anything. Leaving a 60 watt light bulb on overnight will “eat up” a lot of your battery reserve. It can be done … You just need more batteries … And solar panels to make it happen.

A little common sense would tell you … If you do not need it … Turn it off!

Common sense probably won’t tell you how much power will be wasted by using the wrong wire. Too small or too long of a wire could waste as much power as that 60 watt light bulb.

When using DC power a good “rule of thumb” is always use the largest, shortest wire you can.

So … I bought a bunch of larger wire to replace the stuff I had started the project with, ordered some meters, shunts, heavy duty buss bars, fuse blocks, fuses, lugs, heat shrink tubing … and my new favorite tool … A hand held crimper capable of hand crimping up to # 4/0 cable!

I wanted my systems to perform as well as they could … The solar powered equivalent of a finely tuned sports car as it were.

I’m afraid I’m going to be  seeing lots of 4/0 in the near future …

Something new under the sun!

Always a bit on the curious side … This project started with a visit to the local electronics supply store … Waiting in line and seeing some 15 watt Coleman solar panels on sale. It was a long line … and well … I bought one … and a battery, a small DC to AC inverter, some connectors and a solar charge controller … and apparently … a new project!

Back at my third floor apartment I put the solar panel in my bedroom’s south facing window, read the instructions and had my fish tank’s water circulating pump and heater running off the rig in no time.

I do not think it made it through the night!

I disconnected the pump and heater and waited.

Almost a week later the charge controller said the battery was charged again. (It was a very small battery).

Another trip to the store, a second solar panel … and then a third … this was getting more expensive that I had “planned”.

I plugged just the water pump back in and waited!

The system made it through the rest of the winter, but as the sun started to climb higher in the sky and the leaves on the tree across the street started to sprout the system started to fail, went into hibernation is probably a better description of what happened.

But in any case … The fish were back on the grid!

Fast forward a couple of years … The low winter sun seemed to be the key to keeping the fish happy, though the system seemed to be getting tired. A single cloudy day would shut things down.

Adding a second bigger battery helped … but I had run out of south facing windows,

Meanwhile … back at my “day job” as the owner of a small sound company I had a dilemma. My longest running client’s annual Town Day event was growing, adding another stage in the middle of the town common. With no electrical outlets handy the somewhat uncomfortable solution was to run 100′ of extension cord to one of the outlets they used to power the holiday tree lights. Add hundreds of attendees, some pony rides, a Kids Olympics and a dog show and uncomfortable was starting to be an understatement.

Moving the electronic gear closer to the outlet and using wireless microphones to get to the performers did help, but it was less than ideal and … I was curious.

Later that year I had the chance to fill in as an engineer for a friend at what was supposed to be a wonderful evening concert on a hill top in Vermont. The weather that day was threatening and the concert was wisely moved into an old barn on the property.

While waiting for the “go/ no go” on the outdoor site we checked out the hill top location and saw what was to be the power for the event. A small trailer with a solar panel, not much bigger than all three of my 15 watt panels put together, some batteries and some sort of inverter. The folks from Yestermorrow had donated the trailer’s use for the concert and I seemed to be the only person worried about it … after all, It was my sound system that was going to be plugged into it!

The trailer was used for off grid construction projects. It would be set up at the site, the panel pointed at the sun with the trailer left alone for the week to soak up the sun and charge the batteries.

A construction crew would show up on the weekend with their skill saws, drills and other power tools and build something!

I never saw it in action … But it got me thinking …

A close inspection of my gear showed me the wattage each piece used. Some mathematics some coffee and a trip to the local marine supply store and it looked like I would be able to run everything for the three hour event off of two deep cycle marine batteries.

I bought three just to be on the safe side!

I explained the idea to my contact at Town Day and he gave me the go ahead to try it with the understanding that I would still bring the extension cord … Just in case.

I set everything up early that day and went off to set up the other stages. I left a note explaining that I would be back at 1:00 to pack everything up and gave them my cell number if they should have any questions.

They did.

Apparently a couple of things had been added to the schedule and they would be needing the sound system until about 4:00!

Oh well … I told them I would be by around 1:00 with the power cord but that they should use the battery power anyway.

When I arrived at 1:00 everything was going nicely. I checked the inverter’s built in power meter and it showed that the batteries were still in the same 90-100% full range they had started the day with.

The system ran until a little after 4:00, a total of 7 hours with the inverter’s meter still showing the batteries in the 90-100% range at the end of the day!

The initial voltage off the batteries was 12.8 volts … The ending voltage was 12.3 volts.

I had purchased two 120 watt solar panels and a new charge controller to recharge the batteries after the show.

I brought the batteries up to my father’s house, set the them up on his back yard patio and plugged the two panels into the charge controller.

Four days later the batteries reached a high of 13.7 volts … The first two days rained most of the time … The second two were mixed sun and clouds.

I was very excited and happy, but more than a little confused.

It was time for the learning to begin … And there was lots to learn!