DC - DC Charger Project

[howson]

Thanks Neil
I have everything including the solenoid, it is just a lot more effort and time. But then again doing it right the first time will save time later. Ill tackle the terminal today..

Keith

I wired directly to the Upfitter switches according to the draw required by the device, Keith. The Airlift compressor to a 20A circuit, the Renogy's relay ("solenoid") trigger to a 20A (further protected the very small gauge wire I used with a 1A fuse), then used the two separate 40A circuits for the VIAIR compressor and the winch. Yes, each one requires it's own wiring, but once the work's done there's no reconfiguring to power something. Pic below from my master diagram (updated to reflect the VIAIR and winch):

[ncitro]

Yoda i reread your question and think I misunderstood. I thought you were asking if you could use a upfitter without the solenoid, but now I think you were asking if you could run without any switch right to the battery. I suppose that would work but that would make the Andersen connector hot all the time. Not sure I'd be comfortable with that if it was me.

[Yoda]

Yoda No problem with the boot, my father in law has a TT so no in bed connection and uses his that way.

The solenoid is because the upfitter is not fused or rated to 100A. Depending on the switch you use they vary from 10-40, so you use the solenoid like a switch. The upfitter turns the solenoid on (it's coil draws very little current so use your smallest upfitter), and then the solenoid turns on the power to your 100A cable.

Unfortunately you need that right away.

Thanks Neil
I have everything including the solenoid, it is just a lot more effort and time. But then again doing it right the first time will save time later. Ill tackle the terminal today..

Keith

[ncitro]

Yoda No problem with the boot, my father in law has a TT so no in bed connection and uses his that way.

The solenoid is because the upfitter is not fused or rated to 100A. Depending on the switch you use they vary from 10-40, so you use the solenoid like a switch. The upfitter turns the solenoid on (it's coil draws very little current so use your smallest upfitter), and then the solenoid turns on the power to your 100A cable.

Unfortunately you need that right away.

[Yoda]

OK lets discuss the truck side for a minute and please give me your opinion on this.

First do I really need a solenoid in the circuit connected to an up fitter switch? To have power to the bed plug for other uses like my air compressor, I would need to turn the truck on. If direct wired and fused (100A) it would always be hot, but protected. If I don't want to use the DC-DC charger I can just not plug it it. I could also just trip the Circuit breaker I put in at the trailer, but not sure if it would be a good thing to be powered up and no output connected.

Second bed connection. For now instead of the bulkhead fitting, I was just going to come through a hole and terminate with the booted Anderson connector as others have done. Is anyone having issues with this set up, such as having that connector get in the way?.

I am just short on time right now, but don't want to have a major redo if I change my mind. To use the bulkhead fitting I would just need to trim the boot back on the trailer side. and I can always go back and add in the solenoid. Would not entail much redo - just two more terminals and the up fitter wiring. and I could use an always hot up fitter switch too.

Enough for now - need to get started on building my support tray to keep my generators and fuel cans secure. Sure wish I had my generators back (maybe Monday), but I have my old wood one to start from.

Thanks for the help folks
Keith

[ncitro]

Those look dangerous
I actually was using a dyke plier like this to cut them. https://www.grainger.com/product/2MU...E&gclsrc=aw.ds

Yeah that's what I used for my whole life until a few years ago I grabbed something like what I linked from one of my guys' bag on a job site. I asked him about it and he explained they're specifically made to angle right and get right up against the clasp on the zip tie to not leave a sharp edge. I promise once you try it you won't go back.

[Yoda]

Yoda looks great! A tip for not leaving sharp edges on zip ties. Use one of these to cut them rather than a write cutters and you'll have a nice smooth edge that won't cut or scratch you.

BOENFU 2 Pack 5in Small Wire Cutters Zip Tie Cutters Plastic Snips Jewelry, 3d Printer Clippers Model Snippers Precision Nippers Side Cutters Flush Cutters with Spring, Black https://a.co/d/fcbZJDQ

Those look dangerous
I actually was using a dyke plier like this to cut them. https://www.grainger.com/product/2MU...E&gclsrc=aw.ds

[Yoda]

Just a shot of the loom and D+ wire penetrating the front bay beside the jack. I foamed this back closed when I was sure everything fit.

I then ran along the skirting back to the clearance marker. I again used the 3M squares and zip tied it in place. In addition I foamed a few spots too. The 3" aluminum angle in the picture is supporting the saddle box that I repaired . I did a writ up on this too.


This is the splice using the Wago connector. I added some silicone to the back side and taped it up for protection. Loom is zip tied to a handy propane line. Furnace and HWH are directly above. Not much slack to work with.

Well that it for the trailer side except for the temperature probe, now on to the truck.

[Yoda]

At the bottom of the run the negative goes to the main negative buss bar (below my hand) and the positive swings right and loops up into my Victron Lynx Power In unit thst is connected directly to the batterys, just as the negative buss bare is. This way the BMV 712 will see the charge.



Next up was finding a place to exit the front bay and run the D+ wire to the clearance lights. The closest light is about centered on my unit. After poking around I found there was enough space beside the front jack to fit my loom with wire through it.

This is the back side of the clearance marker I taped into one of the green wires. You can see GD's splice connectors just viable in the foam, This is one time GD did not leave any slack so making the connection was tough. I tried to do a bulb crimp, but ended up using a Wago fitting - it worked well.

Starting at the charger I ran the loom withe 14 awg red D+ wire to the front of the bay and then towards the curb side and down the wall to the outside. To stare I out a jumper in to curt the charge rating to 30A to see how everything works. I thought it prudent to go slow at first.

[ncitro]

Yoda looks great! A tip for not leaving sharp edges on zip ties. Use one of these to cut them rather than a write cutters and you'll have a nice smooth edge that won't cut or scratch you.

BOENFU 2 Pack 5in Small Wire Cutters Zip Tie Cutters Plastic Snips Jewelry, 3d Printer Clippers Model Snippers Precision Nippers Side Cutters Flush Cutters with Spring, Black https://a.co/d/fcbZJDQ

[Yoda]

Ok the trailer side is 99% complete. I just need to connect up the temperature probe. It is a true probe, so I was going to stick it down in between the 4 batterys at the inside corner

Wiring - this was a fun day (NOT!) as I kept banging my head against zip ties I had installed previously. I swear I left a pint of blood and used up a box of bandaids - they did provide protection and padding. It was also hot - high 90's.


First thing I did was assemble my Anderson connector on the trailer power feed. On thing I learned the hare way is verify how the connector fit inside the cover and make sure you have the positive/negative wires on the correct side. Also when crimping on the pins, be sure the are rotated correctly (flat side t outer wall). I now have a slight twist in my cables as I goofed on this. Now if your wondering setting up the cable en like this will make it difficult to use the bulkhead fitting in the truck - I would need to pull the cover back along the cables. I am rethinking the truck connection. I wanted the ends fully covered so dirt and water wold not get in.

This is looking up at the output feed. I looped behind a structure member and looped towards the back of the front bay. The negative line goes to the back wall and then down to the main negative buss bar. The positive cable runs over to the circuit breaker. After the photo I used some 3M squares and zip tied the wires to the upper cross member..


Positive wires connected to circuit breaker

I then ran the positive and negative side to the propane cross over tube and combined then (zip tied as the cross over each other, center of photo) at my central wire run.

[Yoda]

Ok for the rest of then component install

As mentioned before I mounted the DC-DC unit to the front bay ceiling which is also the bedroom floor. This material is only 1/2 - 5/8 thick so you need to be careful of your screw length. The Renogy only has 4 - #8 mounting holes, so to help with a strong bond I used some 3M extreme mounting tape on mounting bracket full width on either end. The middle of the unit is spaced off the mounting brackets, so I did not use any mounting tape there. I think they want this air gap for cooling. I put the outlet side forward to be able to see the indicators easily.



I then found a spot for the 80A isolation breaker. I wanted a spot that was a direct shot to the power in assembly as possible. It too is mounted using the 3M mounting tape and 2 - #10 screws, being careful to space them out so they did not penetrate the floor.

I now have it wired in to my Power in bar for the positive and I ran the negative to the master ground bar I put in with the Multiplus. Pictures to come.

I think at first I am going to limit the output to 30A to get an idea of the operation. I also plan to get the D+ signal from the trailer clearance lights.

Thought so far?

Keith

[Yoda]

Over the past few days as time allowed I have 90% of the equipment and wiring in the trailer completed. First task was running the two #2 welding cables from the pin box to the front bay. I used some plastic coated utility wire (thick bailing wire) and snaked it to the from bay from the pin box area. I did undo the two field bolts either side of the pin box that holds the underside panel up. Took about 3 tries as it kept hanging up in the insulation. An electrical fish tape might have been better.

At the pin box I used the same
restraining clamp that the 7pin cord used and secured the two lines together.


Up in the pin box I found and opening to run the cable through, This took a bit of fishing to get the cable pulled up and through, I first pulled it out flan right at the pin box, right on top of the panel, then fished a wire through the hole and then pulled the cable up. TIP - be sure you don't have any twists or kings in your cables as it can conpound


Truck end is the same as the 7 pin cable. I need to get the Anderson plug installed.

Sorry for the bad photo, but this is the cable running forward on top of the panel to the king pin.

I then zip tied it to the angle supporting the bed room floor. I mounted the DC_DC unit to the ceiling after making sure the power cable bend would work - took several iteration to find the right spot. And YES this time I zip tied to the propane cross over tube instead of drilling and installing clamps.

[Yoda]

I got the answer back from Crown. As the absorption phase is time limited to three hours he recommends the 14.7 and watch.
Keith . He also sent along a maintenance guide that others might find useful.

I’d start with 14.7V & 3 hours; you can always dial one or both back if you begin to see excessive overcharge…

Bottom line on battery care / maintenance – the “lighter” you are on the batteries, the longer they will last and the easier the maintenance and care will be…

Key point again though is regular use of hydrometer to ensure batteries stay balanced…

Please let me know if you need any other assistance here Sir – thanks!

Safety First Guidebook - Renewable Power Batteries_R0422.pdf


Thanks
Keith

[Yoda]

Yoda ... maybe I haven't had enough coffee this morning, but for a Battle Born Absorption is 14.4v and Float 13.6V. From the Solar MPPT configuration:



For the actual switch setting, but I went through the same ???. For the 40A the settings are documented in my thread.

Howard

LOL you do need more coffee. I have 4 - 6V deep cycle Crowns CR260 flooded. The chart I posted was Crowns commendation. I am still in the dark ages on batterys.
Thanks though
Keith