2010 3500 RV build

irontent

New member
So your planning on using the sprinter engine as a generator motor?
I have been told that idling the Sprinter for an extended period of time is a bad idea due to "black death". The main application of the second alternator is to run the house AC and charge the house batteries while driving. The front AC does a reasonable job of cooling the cab area, but my wife found that riding in the rear of the van warm in hot weather without the house AC running.

I expect the solar panels to charge the house batteries while boondocking during the summer enough to support the fridge and evening LED light with some HF radio use.

It is interesting to note that Road-trek in their new eTrek conversion uses a similar, second engine alternator and advertises it as an engine-generator. I guess time will tell if their vans have the black-death issue if the Sprinter engine is used in that fashion.

Hein -- sorry about highjacking your thread. Over to you ...
 

OrioN

2008 2500 170" EXT
I have been told that idling the Sprinter for an extended period of time is a bad idea due to "black death". The main application of the second alternator is to run the house AC and charge the house batteries while driving. The front AC does a reasonable job of cooling the cab area, but my wife found that riding in the rear of the van warm in hot weather without the house AC running.

I expect the solar panels to charge the house batteries while boondocking during the summer enough to support the fridge and evening LED light with some HF radio use.

It is interesting to note that Road-trek in their new eTrek conversion uses a similar, second engine alternator and advertises it as an engine-generator. I guess time will tell if their vans have the black-death issue if the Sprinter engine is used in that fashion.

Hein -- sorry about highjacking your thread. Over to you ...
The high-idle option feature is meant to help with engine issues. The second alternator then will help running the A/C, when driving. Is the house A/C AC or DC?
 
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irontent

New member
The high-idle option feature is meant to help with engine issues. The second alternator then will help running the A/C, when driving. Is the house A/C AC or DC?
I have the variable RPM high-idle feature as well, but I doubt I will really need to run the engine while parked just to generate power. But, at least I have the option.

The house Air Conditioner is AC only and runs well off the Magnum inverter. Without the engine running, I get about 1 hr of Air Conditioner until the batteries approach 50% SOC.
 

OrioN

2008 2500 170" EXT
I have the variable RPM high-idle feature as well, but I doubt I will really need to run the engine while parked just to generate power. But, at least I have the option.

The house Air Conditioner is AC only and runs well off the Magnum inverter. Without the engine running, I get about 1 hr of Air Conditioner until the batteries approach 50% SOC.
Have you tried it, at +100A draw, doesn't the low-voltage feature of the Magnum turn off the inverter well before 50% SOC, and more like 75%?
 

hein

Van Guru
Dual alternator setup is definitely on my to-do list.

I drove the van with the combiner and it worked as expected. It did not connect for a while (not sure how long). I am pretty sure the Scangauge reported higher than connect voltage before it actually connected but need to verify that. I am using the 'sense' lead direct to the chassis battery. The disconnect relay got a little bit warm (not hot) so may need to upgrade that. I'll watch the status leds a little more closely next time.
 

irontent

New member
Have you tried it, at +100A draw, doesn't the low-voltage feature of the Magnum turn off the inverter well before 50% SOC, and more like 75%?
The SOC started dropping more rapidly at about 70%. I turned it off at about 65% SOC which was about an hour. I did not make note of the voltage just before I turned it off, but from memory it was under 12 volts. After a few minutes, the battery voltage returned to 12.3 volts. I mainly tried this just to stress the inverter and to confirm the system operation. During the test about 10 minutes in, the DC current (measured on the Pentametric) was about 163 amps while the AC draw (measured with a BlueSea AC Panel meter) was 16.5 Amps at 124.4 Volts.

I let the battery stand overnight with no charging or loads other than the slight draw from the Pentametric, and the voltage recovered to 12.4 volts the next morning suggesting a state of charge of 66% from the Lifeline documentation.

For grins, I measured (using a Fluke IR thermometer) the surface temp of the 4/0 positive cable feeding the inverter at 110 degrees F. The ambient temp in my shop that day was 85 degrees.

YMMV

I don't plan to run the Air Conditioner on batteries alone, but it was nice to know that my system worked.

All - if you have more questions / comments, it probably makes sense to post them on my build thread "Cargo Van to Iron Tent" so we keep Hein's thread focused on his build. I plan to bring my build thread up to date in the next day or two with my build progress.

Thanks Hein, for your patience.
 

hein

Van Guru
CNC'd parts for the bathroom door. Then assembled and installed it. It hangs on a 6' black piano hinge with a lot of screws. The door is constructed from two layers of Celtec with panels sandwiched between them. The black outer layer is 1/2" (.475") thick and the inner layer (bathroom side) is 1/4" (.236") thick gray. The two layers are laminated with contact cement. The top inset panel/window is 8mm clear Polygal (leftover from a greenhouse project) and the bottom inset panel is 1/4 gray Celtec. The bottom panel is only visible on the front. The top of the door has some slots with a sliding panel to open/close them. I have a heat duct in the bath so this will let that warm air into the rest of van. The latch is a Southco M1-25-62-18.



Vent detail:


Below. Inside latch with one of our stick on handles.



In hindsight, I should have moved the latch a little closer to the jamb so the metal catch is flush. It sticks out and I'll probably tear my wetsuit on it one day. When that happens it might be time to machine a new door.
 
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casdclassb144

New member
Very nice , I would never have the patience or couldn't even accomplish, I purchased my Roadtrek SS agile all done and will make minor changes , turned the sofa sideways , just fit to and still folds down and next is the Electrical

Curious how far you went of the sliding door entrance, Looks like its on that side.

Nice Job
Chuck
Roadtrek SS Agile
 

hein

Van Guru
Curious how far you went of the sliding door entrance, Looks like its on that side.
Thanks for the compliments. I am sorry that I don't understand what you are asking. I would be happy to give you some measurements.

P.S.

Today I made a 14x20 mirror and stuck it to the bathroom wall with some...
you guessed it!
V-H-B tape.



The position is nice for primping and also covers 4 screws that help secure the forward wall panel. The frame is machined out of 1/4" thick haircell ABS and has a recess in the back for the 1/8" thick acrylic mirror. The light in the bathroom is a Hella 2JA 007 372-001 florescent fixture that was originally in the van as an overhead light. The light was a bit harsh so I added a valence made from a rectangular piece of scrap Celtec. Stuck it to the light with some more VHB. It's at the top of the outside wall.
 
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casdclassb144

New member
after going back and reading your posts your bathroom is in the back and not in the middle where the sliding door is, Roadtrek uses part of entry of the sliding door for the bathroom
 

hein

Van Guru
I've been trying to finish up the design of the stainless steel combination black/grey tank so I can get it released to fab. I'm not an expert on tanks so please post your comments.

Center section is black and the two outer sections are grey. The tank hangs under the back of the van from the rear spring mount and the hitch arms. (I have Glide-Rite air suspension which only uses the front spring connection points). Picture of underside of van here.



3D model if you want to spin, rotate, take cross sections and even measurements:

http://www.impact3d.com/tank_single.eprt

viewer: http://www.edrawingsviewer.com/
 
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chromisdesigns

New member
If you can find space for the plumbing, add a washout connection at the top of the black tank to connect a hose to flush the thing out. Since you are CNC fabbing the tank, some kind of hat or umbrella shaped diverter a few inches under the washout port would help scatter the water to sides of the tank and add to effectiveness.

Integrated flushing/washout beats the heck out of those add-on systems, or having to stick a probe or hose down the toilet...!
 

GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
V shape could cause rapid fluid rise at bottom of the V during an acceleration or deceleration. In the black tank you have either vent or intake hole and an acceleration/deceleration could cause rush of fluid upwards, from that perspective I would keep side walls parallel to each other or place vent/intake on the top of the V if the V is needed for mechanical rigidity.

If you would like to be the owner of the best and the only one in the RV universe a Self Cleaning SS tank you could opt to attach from outside a 100W ultrasonic transducer(s) on the bottom of the black tank. Imagine your fellow campers buzzing about it.
http://www.ultra-piezo.com/Products/ultrasonic-transducer/

George.
 

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