cargovanconversion
Florida, USA
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Great idea to be using an accumulator, but at the same time I wonder whether in a one person van, with limited amount of water, one would use it that frequently.
Would it make that much in amps draw?
Van.
My website describes the conversion of my Dodge B-250 van into a small RV. I deal with a lot of woodworking, but hope to be quite specific on solar as well.
cargovanconversion.com
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neil.hank202
Colorado City
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This thread is a mighty great resource!
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WVvan
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Quote:I have never been able to get my SHURflo accumulator to hold pressure over a long period. So you may want to locate the bottom pressure value of your accumulator so you can conveniently pump it up once it has lost the pressure.
Thanks for the tip. I'll keep that in mind.
Quote:I wonder whether in a one person van, with limited amount of water, one would use it that frequently.
I was thinking of when doing dishes which has the faucet continually on and off.
Quote:This thread is a mighty great resource!
Thanks.
Open the pod bay doors Hal.
Once I exit Hal, this is what I do.
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WVvan
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Kitchen Cabinet, Post 7
Looking at what to do next, I thought an additional support across the frame near the bottom of the water cans to help hold them place would be good.
So added one.
Next is the 3-way valve. Will use this to switch between the two water cans.
There are two thread holes on the valve.
These turned out to be threaded for #10x24.
Weld up a small bracket to hold the valve.
Add four T-nuts to the countertop.
I'll mount the valve to the under side of the countertop.
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2112
Texas
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WVvan wrote:House battery frame and venting, Post 5
Need to add vent fans to the lid. Even though hydrogen is lighter than air and should naturally flow out if the vent outlet is higher than the inlet I want to give it some assistance. The amount of hydrogen gas produced by a charging battery at any one time is fairly small so I won't have to move a great deal of air. I'll be using small 12 volt "muffin" fans. This is a induction type fan so it has no brushes that might produce electrical sparks like a regular motor.
I just stumbled onto this ambitious project and I must say I am quite impressed. You sir are an inspiration to any DIYer. I do have a few comments if I may. I am a bit concerned with the placement of the fans. True, in a perfect world you should be offgassing minimal hydrogen. But what if you experience a charging malfunction that causes excessive offgassing? Furthermore, the older the cells get the more they will offgas. Even though you are using brushless DC fans that does not make them inherently explosion proof. And with time the acid will eat away at the electronics within the fans. May I suggest mounting the fans at the inlet vent and using them to provide a positive pressure within the battery conpartment and have the exhaust vent at the high point? Just pointing out what I see. I would hate to see you and HAL on the 10pm news with a lead-in of "boom".
On the current sense driver, it seems to me that your gain is way too low. You're down in the mud where thermal and gain errors as well as noise may give you problems. Crank up the gain to where a small current flow will saturate the output to eliminate these errors. You don't care if it is sensing 1/4A or 2A so peg it and raise the ucontroller input threshold a bit to eliminate false triggers from noise. Saturation (max output)should give you about 1V output.
I'm following the HAL project with great interest. Good luck and have fun.
2011 Ford F-150 EcoBoost SuperCab, Timbrens, PullRite SuperGlide 2700 15K
2013 KZ Durango 1500 2857
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WVvan
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Hi 2112,
Quote:But what if you experience a charging malfunction that causes excessive offgassing? This one got me thinking. There are three ways I'll be changing the house batteries. When plugged into 110AC, off the solar cells and via the van's alternator. Both the 110 AC charger and the solar control are "smart" chargers so I'm not worried abut them overcharging. The alternator is another story. The van's PCM should notify me via the dash alternator light if the charging system starts operating outside of it's normal range but I'm going to add a backup. The house batteries will be tied to the van starting system through a solenoid relay. I'll incorporate a voltage measuring cutoff to the solenoid circuit. If the van's charging circuit starts putting out excess voltage the solenoid will disengage separating the two electrical systems. That will hopefully take care of charging malfunctions.
Quote:Even though you are using brushless DC fans that does not make them inherently explosion proof. True. That's why I added a spark arrestor between the fans and the top of the batteries.
Quote:.. with time the acid will eat away at the electronics within the fans To compensate for this I bought 12 identical fans. That's also why I designed the fan enclosure the way it is. The microcontroller will monitor the fans performance through it's current usage. If that current changes enough in either direction it would sound an alarm so I'll know to check the fans. If there's a problem I just pop in a new set of fans.
I've heard the "bark of the hydrogen hound" in chemistry class and seen the Hindenburg* newsreels so I know there is an element of risk in having the batteries inside the van but have tried to plan accordingly. I fell safer with my arrangement than I would with AGM batteries and no plan for venting like I've seen others do.
I'll PM you abut the electrical gain for more details.
*Hindenburg Trivia* Herbert Morrison ("oh the humanity!") died here in this town in 1989. He and his wife moved here because it was her home town.
* This post was
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edited 05/23/12 02:13pm by WVvan *
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2112
Texas
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What you want to seperate is the gas the fan is moving and the circuit board in the fan itself. That is why pratically all explosion proof blowers are squirrel cage with the motor external from the gas path. Open up one of the fans to get to the circuit board. You will find the red and black wires soldered onto the pcb. Notice how close they are. What COULD happen, not saying it will, is the wire corrode at the solder joint. If either break loose and come in contact with the other, spark. If the red breaks loose and comes in contact with many things in there, spark. Granted, it would take a two tier failure mode to get the boom. Hydrogen above its LEL AND a malfuntioned fan failed in a manner to create the ignition.
If you're comfortable with what you have, and I understand the pushback because you have a lot of time invested in it, go for it. If you find opening the fan to gain access to the circuit board an easy task, cover the circuit board with some silicone RTV conformal coating or epoxy sealant. We use Dow Corning 3140 but there are other, cheaper brands out there. If you do decide to conformal coat and go with the spray type mask off all mechanical components before spraying.
I actually dreamt about converting a van last night after reading your thread. I'm inspired 
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WVvan
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Kitchen Cabinet, Post 8
Next up. Decide where to locate the spray attachment that came with the faucet.
Drill a hole in the countertop for the spray head.
Install the T-nuts for the piano hinge.
Replace the wood screws with #10x32 screws and T-nuts.
Give it a swing.
Looking at the frame I wanted to change the lower side brace for the water can. It was originally at a 45 degree angle but that wasted space.
So I cut out the angled one and replaced it with this curved one. This gives me a little more room next to the water can for storage.
There is a gap of five inches between the water cans and the front of the cabinet. Started thinking of what to do with the space.
Looks like a good place to add a small waste bin.
The bottom of the bin has to be high enough so it doesn't interfere with the water cans as they are tipped in and out through the back.
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WVvan
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Kitchen Cabinet, Post 9
Start deciding where to mount the hinges for the cabinet doors. There will be three doors. One at the back where the water cans are inserted and two on the front.
About to make a big Mistake. Truth be told, by now I'd been working and welding on the cabinet frame for a couple weeks and was pushing to get to the next phase so didn't think this step through.
Welded up six simple angled pieces that will be the hinge mounting pads.
Then welded them to the frame where I though was the best location for each hinge.
Don't have a separate photo but I added a 1/2" angle iron support across the front to support the waste bin door.
Also welded on four pre-drilled tabs that will support my version of an electrical sub-panel.
If you look in the center of the above photo you can see the last thing I welded onto the frame. It's a collection of 1/4" steel rod that will hold the cabinet's cutting board. At this point I realized I was officially out of control with the welding and had to stop adding bits.
Here's what I thought was the final version.
Weighs in at around 27 lbs.
Thought that if I quickly primed and painted the frame it would stop me from welding on it again. Wrong.
Cut a piece of plywood to fit the shelf space. Has to clear the water can.
Take the wood panels I'd made earlier for two of the three sides of the cabinet and cut out the openings for the doors.
Screw the front panel in place. Take measurements for the doors.
Cut out the doors from a sheet of 5/8" plywood.
When I went to mount the doors I realized my mistake from earlier. When making the mounting pads for the hinges I didn't properly account for the thickness of the covering panels.I didn't pre-drill the hinge mounting holes because I'd have to shift the hinges to fit the panels but underestimated the distance the hinges would have to move.
Nothing to do at this point but suck it up and mount a cutting disc on the angle grinder.
   
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WVvan
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Kitchen Cabinet, Post #10
Cut and drill a new set of hinge pads.
I probably did myself a favor by messing up the first set of pads. The plan was to drill each by hand but it's so much easier to do on the drill press.
This time around I custom fit and weld each pad in place. One door at a time.
Install #10-32 T-nuts into the doors.
Check that the water cans will fit through the access door as expected.
Take everything apart and paint the frame.
Stain all the plywood doors, cover panels and the countertop. All sides.
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* This post was
edited 05/25/12 09:48pm by WVvan *
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