Hal The Van

[unimogdave]

I second the down stream concern, with all that plastic and a spinning fan i would be concern about static charge. (Hindenberg). from my understanding sealed wet cells marine batteries do not discharge much gas but capures it in the caps. What about just venting the caps. use a small tube 1/8 from the cap to the outside of the van. I'v been running two 110 amphr rv batteries in the van for 2 years with no problems.


Dave

[WVvan]

From what I've read, to safely vent the gas without any fans required a vent hose and opening around 2 inches in diameter. That didn't fit in with my design so I'm going with the fans and smaller hose.

If the van contained the same concentration of hydrogen that the Hindenburg had I'd worry more about the possibility of static buildup too. Having the fans running whenever the batteries are charging should prevent enough of a concentration where static can do any harm.

Anyway that's the plan.

[WVvan]

House battery frame and venting, Post 6

With the vent fan enclosure done next up is the vent outlet. Here's what I bought to be the outlet on the side of the van. It came from a online marine store. It fits a 5/8" ID hose.


First decide where I want to mount it on the side of the van. It has to be higher than the level of the batteries but not too much higher to keep the hose run as short as possible. It's a trade off. It also has to be where the inside of the outer "skin" of the van can be reached so I can tighten the nut on the vent fitting.

Here's a picture of the inside of the van shortly after I bought it. Look just above and to the right of the fuel intake "hump". There is a roughly oval shaped indentation on the inside metal framework. That's the area I'm aiming for.


Here's that same area with the insulation in place. I've already drilled a pilot hole in the location I picked.


The view from the outside of the van. Having cut and drilled so many times on this van already it shouldn't be that big a deal putting another hole in the side but there's still plenty of trepidation before starting the drill.


Use the hole saw sized for the vent fitting and drill through the van.


On the inside of the van I'd cut the insulation before drilling but it was still in the way.


Perfect use for a couple binder clips.


Need to drill a hole on the inside metal framework layer that will allow me to work on the vent nut so size the hole saw to the nut.


Mistake. I should have used the pilot hole as a guide for the larger inside hole before drilling through the outer skin. Without the pilot hole to keep the drill centered I tried to hold the drill steady. The scratches in the metal show I wasn't totally successful at keeping it centered.


Here's the fitting in place and tightened down. There is enough room between the fitting and the edges of the hole in the metal framework to work needle-nosed pliers. In this picture the scratches have already been painted over.


The view from outside. I used silicone II on the hole edges before tightening to try and keep it watertight.


The vent hose attached to the inside of the vent fitting. The green hose in this picture has been changed out for heater hose which has a thicker wall and is less apt to kink.


The vent hose attached to the fan enclosure on the vent lid. In this picture you can see how the top of the lid is angled so the hydrogen will rise towards the fan enclosure end.




Here's an example of serendipity. I originally was going to have the bungee hold downs on each end of the lid but the fit is too tight between this end and the sofa-bed end. So moved the hold-down to the front of the lid at that corner. Started thinking about how to create an attachment point when I noticed my far less than perfect welding on the battery frame had created a little spur. The hold down hook fits it perfectly.


continued -

[WVvan]

House battery frame and venting, Post 7

After completing the venting lid with it's exhaust hose and enclosed fans there was the question about how to control the fans. I didn't want the fans running all the time since they would just drain the battery. If my only charging system was the alternator then I could power them from the running van but I'm going to have solar so that wasn't the answer. How about having the fans run when the batteries were above a certain voltage that would show they were being charged. That wouldn't work either since the resting voltage of the batteries will probably change as they age and anyway I'm not sure of the voltage level put out by the solar charger and how it will fluctuate with the sun.

I'm no expert on electronics but I have dabbled in them before so I went to Digikey and started searching around for something that might be used with a charging battery. I found the Maxim MAX4376. If I was reading it's datasheet correctly it might work. So ordered a couple.

Ran into the first problem. Here is a MAX4376 sitting on a penny. It's a really small surface component chip. Never messed with these before. Don't think I'll be able to solder on something that small.


So started searching online. Found a way to solder something this small. It involves solder paste and a electric skillet. So order some solder paste. The paste comes shipped with a ice pack to keep it cold so you store it in the fridge.

Also ordered a small circuit board that is made for this style chip. Put the paste on the circuit board pads then place the chip legs on top of the paste.


I used a dental pick to clean off the excess paste after taking the picture.

Next get an old electric skillet.


The paste has a specific temperature versus time profile you're supposed to follow. Took me two tries to get it right.


It works. Here's the chip soldered into place.


The circuit board is big enough for me to solder pins through the eight holes and use on a breadboard.


Here is my test rig. I have both a load on the battery and a charger connected.


I've got the chip mounted on a breadboard and connected to the battery via a sensing resistor as recommended in the datasheet.


When the battery is under load but not charging the MAX4376 outputs a signal of .008 volts.

When charging the signal jumps to .021 volts. This value changes as the current into the battery changes. The signal voltage range can be changed with a different sensing resistor.


OK now that I have these value what do I do with them. Well I always wanted to learn about microcontrollers so these seems as good a time as any.

Here's the microcontroller I decided to learn on. It's an Atmel ATMEGA168P-20PU. A microcontroller is like a limited function computer. So a computer for $4.85 is a pretty good deal.


The low price is the good news. What's the bad news? The fact that I knew next to nothing on the subject of microcontrollers. At the beginning of the battery venting project I talked about hitting a slow patch. Well this is it. I had to learn a new whole subject. Here is a picture of all the manuals/info/tutorials I downloaded off the internet and printed.


I won't say I've read everything in this stack but I've read most of it. And some of it more than once. This took weeks and weeks. I won't go into much detail about how microcontrollers work since this post is already pretty boring by now. Basically you write a computer program and load it into the microcontroller which tells it what to do then test it. If it doesn't work like expected you change the program and load it into the microcontroller again and see if it works. It can be very tedious so patience is required.

I'm writing the program in assembler language which is a type of computer code. I had a class in it once a long long time ago, back when dinosaurs ruled the earth, so that helped a little. By the way if you've seen the first "Terminator" movie you've seen assembler code. It's what scrolling up the screen when you see the world through the Terminator's eyes. "Hey, buddy. You got a dead cat in there, or what?"

So I built a circuit on the breadboard that includes the microcontroller.


Add it to the rig and start testing it. After much work I got it to do what I want.


Here's a simplified version of what the microcontroller does in this setup.
Every 30 seconds check the output from the MAX4376 chip. Decide if the battery is charging. If it is then make sure the fans are on and functioning OK. Sound an alarm if there is a fan problem. When the battery stops charging run the fans for 5 more minutes so to be sure to purge any gas from the vent lid.

There's more to it than that but if anyone is interested in the gritty details they can PM me. If this one application was the only use I had for microcontrollers then this would have been overkill for just the vent fans but there a several different projects I have in mind. This just gave me a good excuse to finally buckle down and tackle the subject.

Haven't built the final version of the circuit board that incorporates everything yet but I'm far enough along to be sure I can get it done. It won't be needed until I can get the house batteries charging system in place. So I'll stop posting on the battery venting project until then. Next posting I start on something else.

[Ford_6L_E350]

Originally Posted by WVvan

I won't say I've read everything in this stack but I've read most of it. And some of it more than once. This took weeks and weeks. I won't go into much detail about how microcontrollers work since this post is already pretty boring by now.

I've never thought any of your posts were boring. Far from it. Educational, yes. Encouraging, yes. And much more.

I find it hard to believe the projects you've undertaken (buy a welder, learn to weld; buy a microcontroller, learn to program, etc.) while working on your van. You are truly an inspiration!

Mike

[BroncoHauler]

There's nothing here any of us couldn't do. Me, it would take me about 46 years to make this much progress though.

Truly impressive all the effort you've put into your van.


Herb

[WVvan]

Thanks guys. I appreciate the encouragement.

BFD (Big Flooring Deal), Post 1

Putting down the floor and securing it in place is for me a big deal since it signals the end of one phase of the van conversion. Up till now I've been able to pull up the flooring whenever needed to work on whatever new project I dreamed up. It's just been laying in place. To start adding cabinets, building up so to speak, I've got to decide that there isn't any more reasons for the floor to come up. So I've got to commit to the final design. That's why this is a BFD.

But of course there a couple of last minute changes I want to make first.

Here Tiger is pointing out one of the problems that need fixed. There is a floor seam that runs from the middle of the battery frame towards the side door. The seam is in the middle of the door opening and anchoring the ends could be a problem.


When standing outside looking into the side door this is the right floor piece...


And this is the left.


Get a new sheet of plywood (11/32") and using the other two pieces as guides cut it so the seam will now lie to the left of the fuel inlet hump. The new sheet doesn't cover the same width as the first two flooring pieces so part of the left piece is reused. Now it's a solid sheet of plywood at the side step edge.


As you can see in the previous photo I'm sealing the plywood before securing it to the floor. Here's what I'm using. The only reason I'm using this particular stain is because I already had this gallon on hand. It did the job OK. Two coats, top and bottom.


Here's comes the hardest part of this project. The basement opening.


In using the basement day to day I've found the opening isn't large enough to easily allow the passage of a body. Sorry did I say body. I meant sack of potatoes. Yeah, a sack of potatoes. And it's even harder if that sack of potatoes is struggling.

Just kidding. When creating the opening for the basement I thought the widest part should run side to side. Having used it for a while I'm thinking that having the widest part run front to back matches better with the center aisle layout of the van. It wasn't the work of changing the opening that bothered me but the fact of redoing something that was working just fine. Also I'd have to trash the custom built hatchway door and frame since it wouldn't fit the new opening. Had a long debate with myself over this one since it was either change it now or forget about it.

What finally won me over to the change was the need to weld the floor to fix the earlier cut. I'd never welded on the van itself before so this would be something new.

How it looks after enlarging the basement opening.


I'll weld a patch to close up the section of floor where it was previous cut. Use a wire wheel to remove the paint from where I'll be welding.


For patching material I'll use the section of metal that was cut from the van wall where the side window was installed. This is Hal's version of a skin graft.


Before welding on the van I had to make up an heavy duty 220 extension cord so the welder would reach outside.




Here's the patch welded into place. Need more practice on thin metal welding but think it will hold OK. You'll notice I didn't try to bend the metal to match the floor ridge. This metal is too thick for me to do more than a simple bend with my homemade bending rig so just welded it flat. Since the underneath of the van at this point is protected by the basement it's not that big a deal. If the patch was on a part of the floor that wasn't over the basement I would have done something different.


Before starting to weld I disconnected both the positive and negative terminals on the van battery. I've read online where some people do and some don't. Didn't want to take any chances and it's not that difficult.

Prime and paint. Using Rust-Oleum white enamel paint. Doesn't match but who's to know.


Notice the gap at each end of the patch where the floor ridge dips down. Seeing that gap got me to thinking. I'll come back to that.

Cut and stain a new sheet of plywood to match the new opening. After making sure it's a good fit take the plywood into the garage and use it as guide for the new hatch frame.


Here you can see the whole floor after staining along with the new hatch frame.


Speaking of bodies, I'm staring at the new opening and wondered to myself if I would fit in the basement. It took some maneuvering but was able to get all six foot of me, head and all, into the basement. After I got my arms inside couldn't reach the camera.


The plywood will cover the edge of the side plastic step so have to secure the step first. Here are the original fasteners for the side step. I replaced them with metal bolts and nuts.


Use #10 sheet metal screws at each corner of each of the three plywood sheets that make up the top floor layer. My plan is to bolt each cabinet I add in place through the floor. I'll be doing the same to the sofa-bed. It's the bolted down furniture that will keep the plywood in place. The twelve screws should work until then, hopefully.


continued -

[WVvan]

BFD (Big Flooring Deal), Post 2

With the floor down, time to cover it. I'd thought about indoor-outdoor carpet but if I'm camping in the rain, which does happen, it would surely get wet and that could be a problem. So I'm going with vinyl flooring. Next choice is either sheet vinyl or tile squares. Since I still haul things in the van there is a chance of the floor being damaged. If I go with squares and damage one it can be pried up and replaced. So tile squares it is.

The floor space measures roughly 6' x 10'. Went to Lowe' to see what they had. The vinyl tiles I picked come in boxes that cover 30 square feet so two boxes should do it. They were around $25 a box. Lowe's also sells the tiles as singles which is a plus since I'll want to buy some extras in case replacements are needed in the future. Can't count on this particular style to still be available after a year or two.

I'll be laying down the tiles in a diagonal or, as I think of it, diamond pattern. I prefer the way this pattern looks but more importantly laid this way the floor seams won't line up with the vinyl tile's seams. The adhesive backing should help hold the floor seams in place.

Start by laying out some squares without removing the backing paper to get an idea how it all looks. Have to plan ahead so that there won't be any small cut pieces against a step edge.


Find and mark the center line of the van. Do this by snapping a chalk line.


Remove the paper backing from the first tile square and lay it down. Use the J-roller you can see in the below picture to press down on the square so it will adhere. This is the same J-roller I bought to apply the Formica to the sofa-bed sides.


Keep adding tile squares building out from the first one.




The downside to the diamond pattern is you have to cut more pieces for around the edges than you would with a straight pattern but I think it's worth the extra work. It helps a small space appear a little larger, at least in my eyes.


As hard as I tried there are still very small gaps between some squares.


Done with laying the tiles.


Cut a new hatch from plywood. Chisel out a place for the pull handle then stain. Apply tiles but instead of trying to match the pattern surrounding the hatchway I made it symmetric to the hatch.


I cut the heads off two 1/4" bolts and welded them to the bottom of the hatchway frame. The original idea was to use the bolts to hold the frame in place but after a test fit I realized the frame was adding rigidity to the floor. So I added another set of bolts to the frame.


Drilled holes in the floor to line up with the four bolts


With the frame bolted into place it made a big difference in the stiffness of the rear floor. There was at least a 1/4" of flex that went away.


Re-used the hinges from the first hatch.


After bolting the frame into place used a Dremel to cut off the excess bolt end. I then took a file to the bolt end till it was smooth. I know I'll be banging my hands into the bolt ends when reaching into the basement so this should help reduce possible injuries.


Looks good.


Last thing I tackled was the side step edge. While doing this project and getting in and out of the van my toe caught the edge of one tile already glued in place along this edge and caused it to flip right up. So some kind of edging along here was obviously needed. I'm going with a simple aluminum angled edge strip I had on hand.


The problem is here where the floor curves. The aluminum edging sure won't bend to fit that shape. I have a couple ideas what to do here but none that I like so just going to punt and leave it be for the present.


Screwed the edging into place.


OK, that's it for the floor. I still have to do some kind of edging strips along the back and along the front but that can wait till later. Once I finished and was looking back over the work it amazed me just how much of difference $50 worth of tile and can make to the look and "feel" of the van.

[WVvan]

BFD (Big Flooring Deal), Post 3

Meant to include this in the previous post but forgot. So I'm looking at the finished floor patch and notice the gap at each end.


Occurs to me that would be a perfect spot to run wires into the basement for a light. Wasn't on the original agenda but why not? Still had some of the rigid LED light strip left over from the fluorescent light fixture upgrade. Cut the strip in half.


Cut up some scrap plexiglas pieces and add a switch. Then use the acrylic cement to glue up a led light fixture.


I notched the insides of the small square fitting on the right end so the switch will snap into place and stay.


Wire it all up to the house battery then use 3M VHB double sided tape to attach it to the roof of the basement. Test. With the aluminum walls of the basement acting like mirrors it's very bright.


Last step. Take scary looking picture.

[WVvan]

Today's job. Finished welding on the kitchen cabinet frame. It's a thing of beauty, at least to me. More work will follow.