The problem with solar charge controllers.

Well, more accurately, the problem with every solar charge controller - regardless of whether it is PWM or MPPT or even direct charging is that they just don't work well.

Picture this scenario: Loads of sunlight, full batteries and the charge controller is doing what it should be - trickle-charging the battery. That's fine. Then say you want to run something like a pair of electric fans that demand a hefty current. That's where the charge controllers all go belly up.

What seems to happen is that they keep trickle-charging the battery while the fans draw current from the battery at a higher rate.  Picture this - fans drawing 4A from the battery and 7A of solar panels in full, glorious sunlight. What you'd imagine would be happening is that the charge controller would be saying "hey, we have plenty sunlight so we can run these fan things directly from the panel power, supplementing that as needed from the battery. That would be the sane, sensible thing to do.

Um, no. That kind of thinking is far too advanced for makers of solar charge controllers. What actually happens (it doesn't matter if it's MPPT or PWM or any other flavor) is that the charge controller keeps putting that trickle charge in until the voltage of the battery drops low enough to merit drawing more power from the panels. So the net effect is the solar panel power is just being wasted and the battery used instead. It's akin to having a free lunch offered to you but opting to go to a restaurant and paying instead.

As far as I can see, most of the solar charge controller engineers need to be lined up against a wall and used for ballistic testing by the ammunition companies. That's all they're worth. What a cockamamie way of building charge controllers!

Wow! More progress...

Again I was in the bus. I spent rather longer than I wanted to, installing the cabling for the shower fan. This was made easier because I'd already installed a spare cable to the inlet on this side of the bus. I have no spare cables ready run now. I don't think at this point that really is at all relevant since I have just about everything that I can think of connected.

I have to report that installing the switch and the fan were a complete success. I still have 4 rivet holes to fill but that's small work. I will probably have to rebuild my riveter.

Today started with rain and it rained heavily last night. Later it dried up and was quite pleasant. I started a new project - covering over the lower window of the back door. For that I needed some sheet steel and what better donor of sheet steel than an old washing machine?

Here, people buy a lot of secondhand appliances. This was a washing machine. Somebody seems to have painted it black over the white. The front had a lovely sized sheet of steel. Of course the only problem with using an angle grinder on sheet steel is that it really eats up cutting disks.

Nevertheless, the front was removed in short order and the remains of the washing machine returned to the storage area. Out of curiosity I tried the lid against some of the smaller windows but it was substantially too small. The big sheet from the front will have to be cut carefully to size.

There it is and it's a pretty big chunk. Well, after that I started cutting it to the right size but my grinding wheel didn't particularly care for the thin metal. Thus I have to get more grinding wheels when I'm out tomorrow.

It has got to the point where it's not really usable. There's only about an inch and a half to two inches of usable disk before they become so stumpy that they're unusable. I don't get this problem cutting thick metal. It's the thin stuff that does my disks in.

Well, that was all my achievements for the day. Not much and there's a pile left to work on.

Things done and things not done.

As I had to do a course at work for half a day I used the second half and went shopping. First off there was Harbor Freight. They had more cable wrap, a pair of cheap ratcheting crimpers for the spade connectors I use. This is important since I damaged a muscle in my right arm. Sad to say I didn't get it from punching anybody's daylights out. I have no idea what happened. It just means I cannot apply the force needed to crimp with a traditional crimper. 

After Harbor Freight I stopped in at Northern Tool. There awaited me quite a surprise. In fact a delightful surprise. I managed to get my favorite 7014 welding rods. Now I can get on with cutting some steel to weld over the bottom back window. I can also get on with welding the steel ankle I bought later from Tractor Supply into a battery holder for my 3rd 35AH battery.

Originally I planned to have just one battery but that didn't really work out. Now I have two and it really makes a huge difference. Three will probably be the ideal. It's not a capacity problem but a discharge rate problem. I cant get enough power out of the single battery in the time permitted. What would have saved me money would have been if I'd gone lithium in the beginning but this whole thing has been a learning progress.

That's the current state of the cockpit - wires to be installed under the bus for the new battery, a 5W solar panel used for testing things, tools and supplies galore. You can even see the new roof vent though I'll definitely need a dry day to install that. I need dry days for the underbody wiring, the welding and the roof vent.

A small thing done today was to complete the wiring for the external solar panel switch. Needless to say I had to pull out my meter to work out which was on and which was off. The switch needs some double-sided sticky stuff to stick it firmly to the ceiling but it's fine otherwise. 

The shower fan finally got installed. The wiring remains to be completed. I just didn't feel like doing it when I'd put the fan in place. That required some soldering since the crimped connections weren't conducting electricity as they should have. That's the problem with the toy wires these CPU fans use. Unlike the bigger fan, this 90mm fan does move air at the base of the shower. I can feel it. That means there's good circulation and it should be good for drying clothes put on a rack in the shower.

No spectacular progress today. Nothing is quite completed yet. Still the same things need doing:

• The sheet metal on the back door needs a dry day.
• The underbody wiring needs a dry day and access to the compressor for the final bit. I'm still waiting for my 10A breaker,
• The roof vent needs to be switched out. I have some epoxy putty and rivets as well as the new event. Since I rebuilt the long handle riveter, that works. My short hand riveter now needs to be rebuilt. The roof vent also needs a dry day.
• The solar switch just needs a piece of double-sided padded tape. I've used all that I have and just need to find more.
• The shower fan needs the wiring to be completed and the switch installed. I have all the bits.

One of the other things I got the other day at Harbor Freight was a metal detector. I can see a fault with the Harbor Freight one in that the telescoping section doesn't work well. It was bought though so that I can check the ground where I want to move the bus to for nails etc. Those things vanish into the sand then surface unexpectedly. Before I move the bus to a new parking spot, I'll put down some tarp or something so that I can suppress grass growth and hence rust. 

Thank God I'm not a millennial!

Today I resolved to do two things - install the shower fan and switch and install the rear solar-input switch and wires. That was the plan. Looking at the box I'd mounted the switch in, there are two small mounting brackets molded into the plastic. Those I measured at exactly 1/8th inch diameter. That's way too small for my self-drilling screws. It's about the size of a 6-32 screw but I don't have any 6-32 rivnuts nor do I have any means to install a 6-32 rivnut as my rivnut puller doesn't have a thread that small.

In the end I decided to bodge it a bit and use the cables to secure the switch box against the ceiling until I can get some double-sided adhesive pads to slip between the box and the ceiling. That'll mean a trip to the store.

In order to put the switch in place I needed to crimp connectors onto the cables. The first of the two crimped on nicely. Crimping the second I had an almighty pain in my right arm. That was pretty much the end of work for today. I'd clearly upset an injury from last week to my elbow. I'd wondered what I'd done - clearly I'd torn or pulled a muscle somehow. My right arm strength is now much reduced.

So, today's two projects are being shelved until my arm heals. Both require crimping to be done. Posting the problem on a mechanics group got the response that I was a silly parsnip for not using a ratcheting cable crimper. In my defence I didn't know such a thing existed and had been using this obscenity from Radio Shack for the past 5 years.

Clearly I can't keep using that. I had a look online and found some from China but with August delivery dates. I need it way before then. At this point it's probably worth spending $20 - $25 for one locally than $5 on one from China that could take a couple of months to arrive - if it ever actually does arrive. I'm still waiting for my 10A self-resetting breaker. The tracking number, of course, is fake. Looking at the seller's feedback, they seem to suddenly have a large amount of negative feedback. So, that's something else to buy when I'm out and about again.

China and eBay seem to go in waves. I'll have a long period of success followed by short periods when everything either doesn't arrive or arrives but is junk. Right now the bus is pretty damned close to completed. It was completed before - or so I thought - then I went on a short trip and found out the shortcomings.

Left to complete - from memory (which is fickle):

• Bathroom fan - including filling old screw holes with rivets.
• External solar switch installation.
• Installation of the cable from the main battery compartment to the distribution point under the bus - including installation of an as yet to arrive 10A self resetting breaker.
• Attachment of some cable wraps to as yet unattached to beams using my air tool.
• Installation of wires from the second charge controller into the battery compartment.
• Construction of a battery holder to have a small battery in the battery compartment.
• Installation of the new roof vent.
• blanking off flush, the lower back door window.

I have had a problem with wasps under the bus. Today I believe two of the three I'd seen got inside the bus. I raced to the house and got the wasp spray, hitting them and knocking them down. The cockpit of the bus now smells like a refinery and that stuff leaves a nasty smell in my nose for ages after. With those dead, I hope there will be no more wasp nest under the bus.

I say Thank God I'm not a Millennial for two reasons. First - a millennial would go crying to their mommy or a physician or a psychiatrist. Second, unlike a millennial, I know its just an accident and there's nobody to blame or sue.

At least 4 inches of rain fell today

After I unplugged the drain holes in the roof vent 4 inches of rain would have had water pouring inside the bus. There was none - aside from the persistent drip over the instrument panel. Even the wall that usually feels moist didn't feel too bad. I might have cracked the wet problem.

I'd been outside to work on the bus. I'd started to put together a switch to turn the power from the external rear solar input on and off. The default (which is manual) is supposed to be "off" just in case somebody accidentally plugs in something of too high voltage. It was the usual comedy of errors but I overcame them all to end up with this.

The holes in the plastic case take #6 bolts so I'll have to see if I can find my #6 rivnuts. With that mounted in place and all in cable sheathing, it should all be quite presentable. I'm putting the plan to put a voltage switch on the extraction fans on hold for now. The new plan with the new simpler switch is to try installing a 3rd battery so the simple switch will be all I'll need.

After that I started to put wires into my new battery connectors. That went well enough for the first three wires. As the wires are 8 gauge I had to use a butane torch to melt the solder and heat the wire. An ordinary soldering iron is not hot enough! So, having got the ends of the wires tinned and the cups on the ends of the connectors full of solder, it was time to solder the wires in. That was pretty easy - just hold the end in pliers, dunk the tinned end of the wire into the solder in the cup and wait for the solder to solidify - that took several minutes for each connection.

Having done 3 wires out of the four, the Heavens opened. It rained cats and dogs and a few camels and baboons too. By the time it ended, the trash cans I'd left open in the yard to dry had at least 4 inches and possibly more water in them. That did not dry out the nasty trashcans and didn't dry out the massive maggots in the trashcans either.

As the ground is sandy, water drains readily. I was able to head out to complete my 4th connection. That means I now have connectors ready to connect to a battery and a cable I can connect into the battery system. I have 3 spare connectors. My plan with them is to make spares for my existing connectors. 

At the moment there is a wasp nest under the bus. I can't see clearly where it is though. At one time they were building a nest by the fuel tank. I took care of that with some PB Blaster. Now I have proper wasp and hornet spray but they're building their nest elsewhere. I'm suspecting it's somewhere over the transmission so I might just have to start the engine and run it for 20 minutes or so just to get it hot enough to drive them away.

Under the bus I want to install my new battery cables. I'm still waiting on a self-resetting breaker from China. I might just break down and buy one locally though since I saw the car parts store sells them. I want also to install the wires for the solar battery charger for the main driving batteries. Finally, I want to use the air compressor in conjunction with my air socket wrench to put cable ties where I can't currently install them.

Inside the bus I need to finish the switch and cabling from the solar input to the charge controller and finish installing the bathroom fan. On top of the bus I need to replace the vent. Other than that there are a couple of things I can do to tidy up internal electrics but that's pretty much it.

There is an idea I had for installing hot water via an instant 120v water heater and an idea I had for installing a 5K BTU AC unit powered by plugin electricity but both are plugin ideas that I'm not currently going to pursue. I keep thinking about installing a bigger gas cooktop but I'm not really all that sure I want to go that far when I can just use my portable butane cooker on a folding table outside. Another idea I had involved using a Harbor Freight tarp and connecting it somehow to the bus and stakes screwed into the ground. Or perhaps just an umbrella that screws into the ground.

New destination

For a long time I had destination signs in my front window on the bus for a laugh. I had for the longest time: "Fort Leavenworth Death Row Express". Then I had "Fort Leavenworth Prison Choir". They were inserted into a plastic sign holder that I'd had for donkey's years. Time for a change!

A few days ago I bought some note-card in 8.5x11 which will be excellent for the lazer printer. The new plan is to print off a few dozen humorous destinations and to use the same plastic holder but this time, glue magnets to it so that it doesn't slide about. The problem with the previous signs is they were paper and just folded and crumpled. I think the card will last longer. 

I didn't do a lot today. It was hot again and about the only thing I can do is to install my new CPU fan. That will involve filling the old holes I'd drilled with rivets. Of course my riveter is being disobedient. Combine that with the fact that I need to get some drywall screws in order to complete attaching the cable ducting to the wall and you can see I have plenty to buy. Just when I thought I'd bought everything and didn't need anything more!

I repurposed the mount I'd made for the old (big) CPU fan and simply ignored the fact it was longer than needed. It's not that important. The important thing is that the smaller CPU fan shifts far more air, far faster than the bigger fan.

While I was drilling the new holes to mount the smaller fan, I noticed the cooling fan from the drill was blowing the fan. That had me thinking about wind generators. My big thing about wind generators is that they are universally huge. The blades are gigantic and not guarded and they generate very little power if any in the usual low wind speeds. Seeing the concentrated air having an effect on the CPU blades made me wonder instead about using my old battery fans to generate power. Rather than having a propeller and a tail I could have a cone around the fan to concentrate the wind and have it on a boom. That way a small 12V fan and a plastic bucket or similar could be used to amplify the wind and turn a worthless 12v motor into a useful generator.

That's about all I did today. I'll have next week to buy myself some half inch cable wrap, blue female spade connectors and some drywall screws. Other than that I think I probably have everything I need. I still have to wipe down my welder and my welding helmet with disinfecting wipes. They've been out of the rat house and stored in vehicles where the heat must surely kill any remaining bacteria. I did pull a wheelchair out at the same time - that I left in the sun for a day where the heat and ultraviolet should kill what washing with Lysol didn't.

100F or 38C is not funny!

Today it's not just hot, it's beyond hot. I had aspirations toward installing the final battery cabling under the bus but aside from the weather being a little too warm, I found that while I have the cables, the cable wrap I have is not big enough. The quarter inch wrap is way to small. The three eights wrap is on the small side too but while I could use it, I didn't have enough to complete the task.

My 10A self-resetting breaker still has not arrived from China though my battery connectors have arrived. I'd rather get the whole length of the cable in cable wrap before I go under the bus and while I'm there I want to replace some of the battery connectors currently in use anyway. Not being able to do everything underneath was a deterrent to commencing. 

I finally figured out a way to put cable ties on the cables where the underbody rib is directly over chassis members or the differential. Both of those mean I cannot use my handy Harbor Freight power drill or my handy Harbor Freight battery drill (for which I bought a new battery the other day). It's really simple - I bought an air wrench when I thought I was going to have to work on a pickup truck that had rusty bolts. I realize now that if I put a socket the same size as the hex head as my self-drilling screws, I can use the air wrench as though it were a power driver.

Meanwhile, I bought a toggle switch the other day. I'd intended to use that with the new USB socket I installed in the bus - you remember - the one when I had the accident and snapped the turn signal switch, forcing me to buy and install a new turn signal switch?

I opened the console and found I'd already put a switch in there. The wires from the USB device were hard wired to the power rail though so they will always be on. I moved a wire to the switch, installing a female spade connector and finding out that I was totally out of blue connectors. Never mind, I doubled the wire back and used a yellow. That worked!

In this picture you can see the control console. There are seven switches that Carpenter never installed. From top left to bottom right...

• Sockets - powers some USB sockets to the left of the console.
• CB - powers the CB to the right of the console.
• NAV - powers the new USB socket which in turn powers my GPS speedometer and an as-yet-to-be-obtained GPS navigation unit.
• REV - powers the reversing horn.
• Camera - powers all 3 of the cameras and both of the C-DVR units in order to record everything happening in front or behind.
• MON - powers the monitor so I can see what the reversing cameras can see.
• Horn - currently powers the bus horn. I do intend to find out what's wrong with the horn circuit and remedy it so that I can sound the horn by pressing the horn button on the steering wheel.

As you may have noticed (which was rather astute of you) the labels for the new switches are stick-on labels with sharpie on them. While I could go out and beg or buy a label maker, I really, really don't see the point. Everything I do on this bus is done for me. I have such rotten luck selling anything that I have no doubt that when I have no use for the bus any more I'll be totally unable to sell it and will likely end up giving it to a farmer to use as a chicken house. Thus there is little point in putting fancy (and expensive) features in that might make it salable. The other thing is that I see so many people trying to sell their conversions after a few years (and even see one moldering in a secondhand car merchant's field) the market is probably flooded.

Add to the flooded market all those people that have bought ready-converted buses or spent a small fortune on having them converted. They will be wanting to sell after a few short years. Those will have all the fancy bits that mine does not. They will be selling them for pennies on the dollar. Then throw insurance into the matter. It's almost impossible to get comprehensive insurance not just on a DIY schoolbus conversion but on one that's not been done by (the agent told me) a major company (one that makes motorhomes as a business). So small redneck companies out in the hills stand no chance - whether they make one or a hundred a year - of producing anything insurable. 

It thus makes no sense to spend a ton on a conversion. Better to do it all yourself and have the challenges of doing it and know how to do it again if something goes wrong - somebody steals your bus or it gets written off in a wreck. 

I've been thinking of welding a steel sheet over the lower window in the back door. As the trailer in which they have been stored has a major rat problem, I went to get my welder today. The welder is usable - it just needs to be wiped down after being left in the sun for a while. The helmet - the same. The leathers are probably so well impregnated with rat pee and rat poo that I'll just condemn them. I suspected I might have to so I bought more gloves when I was at Harbor Freight, the other day.

Not having air brakes on the bus means I have no handy air tank to use for power tools. I have been investigating all kinds of ideas. One that looked feasible is to use a tyre inflater to pressurize a 5 gallon portable air tank. If that was mounted under the bus and the inflater powered by solar battery power or from the alternator when the bus was running, that would allow me a wide array of options. It's an idea I'm playing with. For the moment I'll probably use somebody else's air compressor and tank.

I measured the aperture on the back window at 31 5/8" by 15 5/8". With steel sheet cut to that size and held in place with some welding magnets that I bought at Harbor Freight, I could weld the steel flush with the rest of the door, leaving the original window intact and in place.  There was a slight hiccup to the plan though - the steel on the side of the cooker has folds in it where they're unwelcome. Thus it might end up being a case of having to weld two pieces of steel together before welding the steel into place. That would be quite unwelcome but all is not lost. Appliances here fall like flies so there's bound to be another soon.

Meanwhile, Harbor Freight has elected to stop selling the good welding rods. Now they sell a different brand (at a higher price) and don't sell 1/16th rods any more. To do this welding I can't use a 6013 rod as it doesn't adhere to galvanized steel. I would prefer not to use 6011 as it spatters badly even though it is for galvanized steel. I would like to use 7014 as it does the same job as the 6011 but doesn't spatter.

I have tried 3/32nd and 1/8th rods on my welder and it really does not perform well with either. I'm not about to buy a new welder with the little welding that I have left to do on the bus project. I'd rather hunt for rods and have to order online. I went to Lowes and looked but had the usual run around and had to talk to 5 members of staff, none of whom knew anything about welding (despite selling welding equipment), all of whom waved a pack of 1/16th 6013 rods at me. Eventually they rang somebody and told me they couldn't get them. Sounds like they need a different attitude and a different supplier.

Next I went to AirGas where I met a very pleasant fellow who knew exactly what he was talking about. He had a ton of rods and explained that a 7018 is a 7014 that can be used also for overhead welding. Sadly, he had no 1/16th rods but enthused about how smoothly 7018 rods went on.

Checking online, Tractor Supply is alleged to have 7014 rods in 1/16th but we all know how accurate company websites are, don't we? I must remind my readers of the debacle by the car spares store. They said online that I could order a turn signal switch to be paid for and picked up in store. I did just that and never heard another peep from them other than when I rang I spoke to somebody claiming to be the Store Manager who really didn't sound capable of managing a used diaper.

So, I might just have to order online for the welding rods I need. That kinda quashes advancement over the weekend. Of the projects underway...

• The roof vent - I have the bits - I just need a cooler day.
• The underbody wiring - I need to go out to get half inch cable wrap and blue female spade connectors. I'm also waiting for my self-resetting 10A breaker to arrive.
• The controller for the fans. I'm holding off on that right now. I have another box on the way and want to wire the solar input via a switch into place before I work more on the fan controller. I want to test whether I can just run off all existing panels while they're connected to my charge controller or whether I'll need to put a smoothing capacitor in somewhere.
• The bathroom fan. That arrived. I just need to get down to installing it. I'll have to make new brackets to mount it. I just never thought of doing it today.

I think everything else is done. I did think about the air tank a bit further and somebody suggested getting an engine powered air pump. The problem there is secondhand they're about $500. That's pretty costly. Of course, if I was to do that then I'd want really decent air tanks and that would lead me toward installing air brakes.

Honestly, if I get the four or five current project done, I'll regard the bus as being complete. While I could add a 120v AC unit by installing a window AC unit under the floor, ducted to blow into the cabin, I think my fan ventilation is superior. Needless to say though that when I get the last cabling into place I will probably install another Harbor Freight battery but in the battery compartment. When it comes time to replace all three then I might just put a single 100AH battery in the battery compartment alongside the driving batteries.