Interesting solar panel comparisons

As most of my readers know, my bus/motorhome has solar panels. I have two portable panels and three secured panels. They’re different. The front solar panel is black and is an Amorphous silicone panel.

The Amorphous panels seem to work better in low light but take up more room than the crystalline panels.

The crystalline panels such as this tend to produce more power in a smaller space but they need higher light levels in order to perform. In terms of longevity the crystalline panels last longer but the amount of power produced in low light levels for example cloudy days is perhaps not as good as the less efficient Amorphous panels.

In other news, today I got on with completing the wiring at the front of the bus. It all seems to work. Now I can feed solar power in through an internal or an external source and can feed the bus driving battery from an internal solar panel. Having said that I still have to make the underbus connections.

Still remaining to do on the 12v system is putting the wiring for the door controller in the right place and installing a rear solar input. I have all but the wire for the rear solar input. That means a trip to the hardware store at some point. Then I can get on with cleaning and tidying, sorting and so on.

My first trip with the bus is booked. It’s going to be in early September to a schoolbus meet near Edisto Island (yes, it is on land but I wouldn’t put it past people trying to push me in the sea). I’m looking forward to it!

Look at what arrived in the post today!

Now that is three items. On the left together with a redundant wire is my cigarette lighter socket. That goes through a small hole in the bus skirt. Wires go from that through the floor of the bus to the big box in the middle. That’s a bridge rectifier. From the bridge rectifier a wire goes to the solar controller. I do need to put a switch in between the solar panel and the bridge rectifier, however. Just so I can eliminate the chance of somebody doing something silly with excess voltages.

On the right are two 14 gauge Hopkins connectors. Those are, under current plans, redundant but as with everything redundant I usually find a need for them.

As I said, yesterday, I tidied up some wiring. I didn’t do a darned thing today but then when the temperature is close to 100, it’s hard to do anything more than the essentials and to relax. This is why everybody in South Carolina becomes a lard arse - including myself.

I realised I need a couple of things in order to complete my solar setup - two 12v cigarette lighter sockets (not like the one that’s just arrived), some wire and something to put a switch into. I have plenty spaces for switches - I just lack a box to put my switch. I used my last remaining usable box a few days ago. I have one or maybe two other boxes but they’re not suitable. During one of my previous designs of my solar system, I put too many holes in the one box for it to be usable. Still, I suppose I can try. I can do a lot with expanding foam.

Heaven alone knows where the lid has got to though I’m pretty sure I might be able to find it. The screws that hold it together might be more elusive and it might need to be glued permanently.

The two cigarette lighter sockets are a shopping trip. I have plenty spare wire. I just need to find an extra length of cable wrap. I might have some. It’s not worth a trip to Harbor Freight just for wrap though.

Once the remaining things left to be done are done it’ll be one massive tidyup operation. I’ll need somewhere to put all the tools and oh boy, I’ve really collected tools. Had I known that I could have welded using a pair of car batteries then I might just have bought car batteries rather than a welder and been thus able to use thicker welding rods. That would also have allowed me to weld aluminum which I can’t with my AC arc welder (well, I could but it’d probably spatter badly).

Remaining to do:

• Tidy the wiring for the digital door controller. 
• Install the two extra cigarette lighter sockets. One goes to the news switch in the cockpit. The other connects directly to the charge controller at the front,
• Two wires from under the bus that are not used. Both go to the charge controller. The other end goes into the battery compartment and a pair of alligator clips. When the battery is not in use the alligator clips connect and a solar panel connects to the charge controller so that the batteries can be topped up or kept fresh using solar power.
• The new cigarette lighter socket, wire and bridge rectifier feed into the charge controller at the back, giving extra power. A switch is needed for this circuit.
• The CB coax needs to be reconnected to the coaxial connector. 
• There’s a buzzing relay in the control console that needs attention.
• I’d like to lower the brake pedal some but I’m not sure that it’s possible without removing the hydromax. 
• There’s a bit of paint in the bedroom that needs touching up. I have half a gallon left.
• I need to put the tools in a shed and my surplus supplies also.
• The boxes of stuff that haven’t seen daylight in ten years need to be sorted through.
• Things need to be put in drawers
• I need to go through my clothing fairly ruthlessly. I remember why I kept some items of worn out clothing but the memories they held are not important to me any more.  
• Testing. I need to test the water input and do a test camping session in the bus.

So, plenty to do and I didn’t do anything today! Well, I thought, and thinking is important. Thinking is what separates us from the animals and the less intelligent humans that we encounter on a daily basis. 

Tidying up wiring

For a very long time, possibly two years maybe three I have been considering tidying the wiring for the front door. Well, the top where it mushrooms into my relay and battery pack, it’s harder to actually tidy but I might have another go at that at some future point. Currently the door controller runs off AA batteries. If I felt the urge, I’d change to D cells on the basis that they last far longer since they are of far greater capacity. Some would ask why use independent batteries when the emergency door unlocker is powered by solar. The fact is that it’s backwards - my emergency unlocker should run off lithium batteries but as the digital keypad needs constant power, that’s not an option. I would rather have three key systems - an ordinary lock on the emergency exits, a code key for use with solar power and an electric lock for the front door. Any one of those can fail and still leave me with two ways in.

The electric key lock wiring having been secured and tidied, I moved on to the bathroom. There I’d installed wires in sheath and not properly secured one section. That was on purpose because I wired an extra circuit into the system. It’s not employed but if I need extra power either in the galley or the bathroom, it’s there to provide it.

It’s all hidden away behind the shower where it won’t be bothered. Now there are a couple of bits of wiring left to be done in the cockpit. First the emergency door unlocker wire needs to be tucked out of the way inside the heater compartment and secondly I need to put in two sets of cigarette lighter sockets. The first takes power from two solar panels I might place in the windshield and feeds it to my solar batter and the second takes power from a solar panel in the windshield and feeds it to the bus battery. The bus battery wiring will involve getting under the bus again and passing a wire into the battery compartment. Then while I’m down there, I might as well install the kill switch that came with the bus. It just seems easier to reach underneath to flip a switch than to unlock the battery door to remove the cable.

Now, a piece of fun. I had a can of Great Stuff expanding foam sealant that refused to disgorge its contents. Clearing the nozzle with a twist drill bit I found the drill bit was going deeper and deeper into the can until I was almost half way down. Obviously no foam was going to be forthcoming so I did what every self-respecting American would do and put the can at the end of the backyard rifle range and shot it with some .22LR. Foam immediately spewed from the can and when it set hard I found the shape interesting so I sprayed it pink and put it online as art. I wonder whether it’ll sell.

Finally, I’m still waiting for a couple of bits to come from eBay. These likely will be my last eBay orders. I’m jolly glad to have got to the end of the bus project because until now thing bought via eBay have not been taxed. Some vandals up North decided to disrupt the process and so now one state can now charge tax on everything bought online. I just wonder how they’re going to enforce that. So, remaining to be done... Add a solar input at the rear of the bus, finish the solar input wiring at the front, today the code unlocker wiring and that should be it. I’ll need to test the fresh water inlet but can’t do that where I’m currently parked.

Next follows a lengthy process of cleaning and removing tools and supplies from the bus. Then a period of going through my stuff for things that I have no interest in now and clothes that do not fit. The question of insurance comes up to and whether to retitle or not.

Successes and defeats

Today I found a chunk of aluminum that happened to be the right size to make a one-piece block under the bracket on the one side of the microwave. Thus I drilled a hole and cut it to shape with my angle grinder. Interestingly my Walmart $18 angle grinder seems to cut faster than my $15 Harbor Freight angle grinder. The end result was that in a very short time I had my microwave fully secured. It’s now held down by four brackets screwed to the microwave that are in turn bolted through the countertop. That’s not going anywhere!

The next step was to mount the switch for the solar power supply. That was relatively piainless as was adding a fuse. I just used an in-line automotive fuse holder. That, was simple enough. I still have work to do at the front. I have two spare wires coming from underneath that will probably get connected to the spare charge controller. I’ll put an input from the inside to the charge controller with probably a panel inside the window. The cables below will be connected via crocodile clips to the driving battery in order to keep it fresh.

The wires on the bottom right are part of the door lock control and the plan is to tidy them away into the space underneath the switch console.

I got on and found out which wires to solder where and got a Hopkins two pin connector soldered onto the wires from my solar panels. Then having tested the panel using my solar monitor I got on with putting the other end of the Hopkins connector into the cigarette lighter plugs. Or rather, I didn’t. It turned out to be extremely fiddly and I really wasn’t feeling like very fiddly work today. It was 99F inside the bus with the ventilation off. Thus I looked around and found a cigarette lighter plug with a Hopkins adaptor ready attached. I knew I had one.

I’m probably not going to bother with this fiddly work. Micro soldering has never been my thing. There have been a few things that have turned out to be over fiddly that I’ve quietly junked. These cigarette lighter plugs are going to be another.

The other day I found some Hopkins to cigarette lighter assembleys and ordered one. That’ll arrive in due course. Meanwhile I remember I had a scrolling LED sign that got broken. I cut the cigarette lighter plug and cable off it thinking it might one day be useful. Free hot dinner to anybody that can find it for me though! I suspect it’s somewhere in the galley but I’m not sure where.

Anyway, I got the first solar panel connected and installed. Now the bus is running off 65W of solar panels with the 30W panel better placed to catch the sun.

I have a second panel and connected a Hopkins connector to that also. As can be seen, I propped both panels against the side of the bus. Being $30 panels, I can do this without worrying too much if somebody pinches them. They’re also just the right size to fit inside the windshield. I’ll have to build some kind of mount in order to put them in the windshield but that’s a simple matter of buying aluminum angle, cutting and riveting.

 Not being able at the moment to plug the panel into the bus power supply, I put my watt meter on it and proved it is definitely producing power. I don’t think much of that watt meter - it’s cheap junk but it does work. What I’d have preferred was a simpler device that didn’t consume solar power but ran off a couple of AA batteries.

It was pretty hot today. Inside the bus came in at 100F. Normally if it was 100F outside I’d have been baked out of the bus. One year it got up to 145F inside. Since I put that Rustoleum elastometric roof paint on though, that 67% reflectivity and insulation has cut the internal heat down to the heat of outside the bus. I wonder whether if I’d bought something with 85% reflectivity whether it would have been cooler in the bus than outside.

Even the official outside temperature matched the inside of the bus. This roof paint is the bees knees. It really seems to be working which is quite amazing for what is essentially a tin can.

I went to install my battery meter today and found that the voltmeter I have in place has been soldered in. I have a tendency to do that when I don’t have right-angle spade connectors. As fixing that will require soldering inside the bus, I resolved to wait for a cooler day for that.

How far off completion am I? Hard to say. I know I need to get a couple of cigarette lighter sockets. A double for the house battery side of things and a single for the driving battery side of things. I need to start tidying wiring. There are two or three places that need a little work. Other than that I’d say the bus is probably complete until the results of the first test run.

Using the ventilation and a single 30W solar panel it was noticeable how quickly the battery refilled and how long it would go. I also noticed that immediately the fans came on, though it was still 100F inside, it felt cooler. I’m onto something here!

Solutions to problems

Yesterday was one of those days when nothing seemed to work. It wasn’t restricted to me though - the lady in the grocery store in front of me managed to empty the contents of her purse onto the floor while others had crazy things happen too.

Today the temperature inside the bus with the ventilation turned off was 97F and 56% humidity. It was pretty hot. Outside it was reportedly 96F with a breeze so it felt far cooler. Still I plugged on. The  aim of the solar input is to take the output of my two 30W panels and feed my system with them. That will allow me to have the extraction fan operating full blast during daylight hours. I’m going to add another solar input toward the back of the bus in order to be able to plug in a heftier solar panel or wind generator or whatever. I’m limited to 7.5A on the stuff I have at the front of the bus. With heavier wiring at the back, I can go directly to the charge controller with more power. Extra is not planned but I’d like the opportunity without much prevarication to be able to install more.

As far as the battery goes, 35AH is plenty. If I were to add extra battery capacity then I would not add another lead-acid battery. I’d likely add a similarly sized but greater capacity lithium battery.

After having problems with the MC4 connectors yesterday, I had no such problems today. I took a totally different tack and examined the connectors carefully.

Crimping the wings on the backs of the connectors are supposed in some miraculous way to secure the wire to the pin. I tried that yesterday and couldn’t get the pins into the plugs properly. Today I cut the perishing wings off and simply soldered my wires to the plug for a far better connection. This involved tinning the wires with my electric soldering iron then using my gas torch to solder the wire into the pin.

As can be seen, it worked quite well. Now I don’t have to butcher the connectors on the solar panels. Popping the wires into the MC4 plastic was then quite easy and took no time at all. I was then at a stop because I’d done all I really could or so I thought with the panel wiring.

Yesterday I ordered a set of heavier Hopkins connectors and a Hopkins to cigarette lighter plug adaptor. I needn’t have bothered because I found today that my existing spare Hopkins connectors are 16 gauge. That will handle 10-12 amps fairly readily. Each panel is putting out 30 watts or 2.5A. I probably way overdid it with the wiring but I like to be sure with wiring. I will have a go tomorrow at wiring the existing Hopkins connectors to my cigarette lighter plug and my wires from my solar cable.

My solar cable wires are long at 15 feet but I figured that would be good to pass under the bus and prop up on the other side. There’s also an opportunity to add some kind of clamp and fasten the panels to the mirror arms while I’m parked or even to put the panels inside the windshield.

The next thing I did was to fill the empty spaces inside the switch box with expanding foam. I didn’t have any cable strain relief in place so expanding foam should do the job reasonably well. This will be my switch box. The white is the common and the two reds are the inputs. I will deploy this at the front of the bus to switch the solar input off or on for internal or external plugins. I’ll put a pair of cigarette lighter sockets inside the bus to take the output from the solar panels if they’re in the windshield. The switch has three positions - on for outside and off for inside, off for inside and on for outside and off for both. It’ll stop meddlers from trying to mess with the system as will the fuse I’m installing.

I would have installed the switch box and wired the underbus plugin to it but had to wait for the expanding form to cure. Thus I got on with the next project - securing the microwave. That was pretty straightforward to be honest. I put the four brackets on, drilled the four holes in the countertop and spaced the brackets off the countertop with stainless steel washers. I actually ran out of washers. I should have bought 6 packets instead of just 4. Thus the microwave is bolted securely with three brackets instead of all four.

As can be seen, the theory is simple - a stack of washers and a bolt. Bolting was fun though as the top of the bolt was very close to the edge of the microwave.

I had to get quite creative using several extenders on the cordless drill in order to reach while I had my hand under the counter, holding the nut in a deep socket held via an adaptor in my interchangeable bit screwdriver. I’ll get the washers on my next trip to Lowes (hiss spit).

If at any time I write “Lowes” without adding “hiss, spit” please remind me to add “hiss, spit”. This refers to a time about two years ago when Lowes served me poorly and rudely. Since then they have just been “hiss, spit” as far as I’m concerned. I would have taken my money elsewhere but for the fact Home Depot is several miles further away and going there would hit my bottom dollar.

Arriving in the post yesterday were the next parts of the strap system I’d designed to hold the microwave in place. That was all ordered before I went with my newer system of steel brackets bolted to the microwave. Also arriving in the post was my latest battery monitor. I put voltmeters on my USB charging units but then decided I needed a battery meter as well so I bought one back in May. It arrived today and I’ll probably install it tomorrow. It should give me a better idea of the state of the underbus battery. At the moment that’s reading 13.1V but if I put the light on and the USB charger then it drops to 12.7V. I need something just a shade more accurate though I have a feeling battery level management is more of a witches cauldron than anything accurate.

I’m anticipating being able to use my 12v input within the next few days. As for the internal input then I still need to buy a cigarette lighter socket. I’m not sure why I didn’t just put a double socket on the side of the bus rather than using a socket doubler. Still, if I put the rear socket on then that’s probably not important.

How complete is the bus? The rear solar input is an optional extra that I’m adding. The microwave needs one to two packs of stainless steel washers. The solar input switch needs to be installed and wired and I need to buy a cigarette lighter socket. Other than that I need to tidy the wiring in a few places and it’s done. It needs a test run to see how well it all works and to see what if any modifications are needed.

Problems looking for solutions

Today I looked into both extending the solar power cords on my solar panels and installing the microwave. I started by working on the solar panels before having to give up on that for the day. It was one of those days when nothing seemed to go right.

Looking up the correct gauge for my wires it seems that I need 14 gauge. Thus, I got some 14 gauge and found it would not fit into the MC4 connectors nor into the cigarette lighter plug. No matter how hard I tried, I just could not get it to fit. I’ll probably have to put thinner wire (which is not recommended for the amperage of solar panel in use).

Looking at the connector on the back of the solar panel, the wires are undersized there too. I’m not a great fan of the junction box either. So, I’ll probably end up doing what I should darned well have done a month or so back - cutting the MC4 connectors off and soldering my new cable into place. Then I’ll solder a Hopkins connector on the end of that and a Hopkins connector onto the cigarette lighter plug. The wires on the Hopkins connector are a bit light but honestly I trust my soldering far more than the flimsy MC4 connectors.

Putting the microwave in wasn’t as straightforward as it could have been either. I’d picked up some stainless washers and a vinyl tile. The vinyl tile was to stop wet under the microwave from rotting the wood of the countertop. Unfortunately when I put the tile down I put it in slightly the wrong place and of course it’s self adhesive. On boy, things really aren’t going well today!

Needless to say, I can work with the microwave where it is but if I can lift the tile, I will and I’ll move it succiciently that it’s on the right pace. As you can see, the tile will catch drips and splashes from the microwave.

The plan is to secure 4 brackets - two at the back and one on each side of the microwave. It turned out that the bolts put in by the maker are long enough that I can go through the bracket and secure the microwave. A pile of stainless steel washers spaces the bracket off the countertop and a stainless steel bolt will secure the bracket to the countertop. Four bolts and brackets should keep the microwave in place and if anybody asks, it’s definitely built-in

So, the plan with the microwave is to move it a couple of inches to the left if possible. I might have underestimated the number of stainless washers needed so I might need more. I’d forgotten that the floor tile would have thickness.

The plan with the solar panels is to throw out those silly MC4 connectors and to solder longer wires to the provided wires then to solder a Hopkins connector to the end since I already use Hopkins connectors. Then I’ll put a Hopkins connector on my cigarette lighter plug. That’ll be far easier to solder. I just have to remember where I put my Hopkins connectors.

So the upshot was nothing of any substance happened despite having bought about $20 worth of wire plus about $10 of other bits and pieces.

Several advances all at once (maybe)

Over the period since my last blog entry I have done several things, none of which was big enough to merit a blog article though. Thus, today you get all the juicy, intimate and dare-I-say-it naughty bits.

A few days ago I worked on my digital door unlocker. That’s now in place and functioning. In fact I went beyond the original plan by including an alarm that sounds when the door unlocker has been used. My regular key lock works just fine and now I have an emergency unlocking keypad in use for times when I don’t have access to my keys.

That’s the magic that makes everything happen. Two relays and a button. When the digital codeock has not been used, power flows from my key door unlocker through the relays. The key unlocker works off 10x AA batteries and they last a good long time. When the digital door unlocker is active, power from the solar battery is used. That operates the right hand relay which cuts off the key unlocker circuit and powers the door unlocker. The button operates the left hand relay, cutting off both the digital unlocker and the key unlocker and closes the door unlocker. That way everything is failsafe.

And there you can see the digital door unlocker installed. When the correct code is punched in, the door unlocks and at the same time, a truly ear-piercing alarm sounds. Everybody within 100 yards will see what’s going on! It’s just an emergency unlocker with a few safety precautions.

The wiring doesn’t look that tidy and I’ll have to tape it properly and tuck it out of sight. When people see bundles of untidy wire they all scream “unsafe” but the reality is what they can’t see is the untidy bundles of wire behind panels. I have never ever seen wire that looked remotely tidy in any vehicle.

I had to do some painting on a derelict mobile home that I’m renovating. Thus I located my paint roller and tray from when I put the elastometric paint on the roof of my bus. The paint peeled out of the tray in a very solid, very flexible, very tough sheet. This is that paint. It’s possible to see that it has turned into a very good waterproof membrane. As far as its insulating properties go, it has already been established that this membrane keeps the bus internal temperature very much closer to the outside temperature.

Having seen the “welcome” signs people seem to put on their bus steps, I went the other way and put a “go away” sign. It goes together with the prison bus look of my bus. The text of the sign is copied from the first two lines of the Groom Lake /Area 51 sign. I figured it looked more official and in keeping with the looks of my bus. I really relish my privacy and being on my own for periods of time. I spent too long in a place where I was screamed at, yelled at, hit, lied to and generally abused both physically and mentally. If this keeps the bullies away, I’m happy.

My next little task was to get some stencils and spray “Max 56 MPH” on the back bumper. I don’t normally get problems from other drivers, driving a big bus but there are some. I figured that might help. I did want to put 55 but there was only one of each number in the set. Likewise there was only one M so the other M is an upside down W. Because the stencil wouldn’t lie flat against the bumper I had to spray through the stencil and the spray has blurred the outside of the lettering. Thus today I sprayed it black as I’d found I still have a small roller and tray. I can apply with a roller - that will be far more satisfactory! I decided also to move the painting to the left side of the bumper anyway.

A small job but a necessary one. I’d not had a fuse on my solar panels before so I spent a few minutes installing one. As can be seen from the red color, it’s a 10A fuse. I doubt I’ll need more. My regular 35W of panels is about 3A and my additional 60W panels come to 5A for a grand total of a shade under 8A. At 95W total amperage would be 7.92A - too much for the next fuse down with is 7.5A.

Today I had a whole load of fun putting this box together It’s going to go on the positive (or negative) side of my extra solar power. I put a 12v cigarette lighter socket under the bus to plug in, extrenal solar input. Many solar panels come with 12V adaptors but with the usual Murphey’s law, my twin 30W panels came with totally different connectors.  Anyway, the switch is three way - on, off, on. That means I can have the external input on or put the panels inside the windshield and plug them in on the inside of the bus. I will, of course be putting a fuse between the switch and the solar collection hub. I figure a 5A or maybe a 7.5A fuse will be best. Again, I’m sticking with automotive fuses.

My plan had been to secure the wires etc inside the switch box by filling vacant space with foam sealant. That was not to be, however. I picked up my can of great stuff and found the nozzle seemed to be clogged. I cleared it with a 1/8th drill bit held between my fingers. Interestingly I went further and further down into the can without even hearing a hiss of gas. When I pulled the bit out I realised I’d gone 6 inches into the can with no release of gas or sealant. That meant that the gas had all leaked out.

Because I’m inquisitive like that, I pulled out my .177 air pistol and popped a .177 pellet into the side of the can. Nothing happened immediately then I noticed a small bead of foam. I put the can down and 5 minutes later the foam was really beginning to ooze out. I’m assuming because air had got in, it was beginning to expand.

What I didn’t expect when the foam oozed out was to see a pale looking Poppa Smurf riding the can. Still, I suppose he’s better out than in!