The Victron Orion XS 12|12-50A DC-DC Charger - Complete Installation and Testing

[jd1923]

I’ve had the parts forever and between work and some travel, a list of injuries (that made it extremely difficult to kneel in the basement or crawl under the truck) I finally have this done, fully installed and performance tested! The bottom line is, “this charger is awesome!”

A month ago, I was working on waste valves under the front dinette seat when it occurred to me to run the charger cabling in the Oliver since I had everything opened. I always drill the smallest hole possible, no fancy cable glands for me. Two 3/8” holes would been enough, but I had grommets in a parts box 1/2" OD and 3/8” ID which were the perfect size. I glued them in place and afterwards caulked all of the cable openings front of hull (no pics taken).

It makes sense to wire the charger before mounting the board (pic1). The wiring is rather simple but the 4 AWG wire barely fits into the terminals. The 4 AWG wire will not fit into the Oliver ground/neutral bus, so I crimped on a lug and cut it to fit the opening. I installed the two grounds side-by-side (the other coming from the tow vehicle) (pic2).

When I worked my earlier inverter upgrade and rewiring projects, I had saved room for the new Orion DC-to-DC charger (pic3 close-up and pic4). The main + bus (in red) is protected by a 90A Marine Rated Battery Fuse (MRBF) that connects by 4/0 cable directly to the Victron Inverter-Charger bus and then through a 400A ANL fuse connected to the batteries (400A Victron Mulitplus spec).

All major circuits are connected to the main bus; the 40A breaker OTT installed for all the Oliver 12VDC circuits, two solar chargers (OEM Blue Sky for rooftop panels and a Victron 30A MPPT charger for a Renogy 400W suitcase) and the new DC-DC charger circuit which is connected through a 60A MRBF (see center of pic3). The secondary +bus (in black because I purchased a set) is protected by the OEM 40A breaker which connects to the 12VDC panel, the 3 jack fuses, etc. These are 8mm thick solid copper buses for minimal resistance. A considerable upgrade compared to the original OEM installation.

I attached the Anderson connection, front of trailer, and then got under it to see all the many zip ties that OTT installed. OMG, they should have better cable management! I replaced a lot of these because of age, but I did not want to merely zip tie this new heavy dual cable harness! Instead, I used the u-bolts that hold the front basket and cut brackets to support the cables including the trailer harness in two places, in front and rear of the basket. The picture shows the front bracket (pic5). And after taking this picture I hammered both ends of the bracket to curve them up almost touching the upper bracket to create a D-shape. I could have purchased pretty brackets, but these were on hand, fully functional and can only be seen while lying on the ground!

The trailer side installation was then done! When I finished and reconnected the house batteries, the blue light on the Orion started blinking and it was listed as a device on the Victron Connect app. So before even working on the tow vehicle installation, I was able to update the firmware and configure the Orion charger. I reduced the output charge to 30A for safety concerns and initial testing. The battery settings were close enough, within 0.1V of the specs for Epoch LiFePO4 batteries.

[jd1923]

Next is the tow vehicle side installation. The Ram Cummins and most diesels have dual batteries. I chose to connect to the RHS battery since there are less connections, because its proximity to the alternator, and because I wanted a straight run down the frame to the RHS of the rear bumper. Looking ahead, last year I installed a custom Nations 180A HD alternator. OEM rating on our truck is 130A, thus gaining 50A for charging ampacity!

Starting at the battery, I ran the B+ cable along the fender rail to keep it away from the heat of the exhaust manifold and entered the main frame member just behind the engine. Conveniently, there are two holes in the frame just behind the front wheel (pic1). The RH opening is where it comes from the engine and the LH is where it continues all the way to the rear wheel. I had 100’ of 1/2" automotive loom from a past project which made for a clean installation! I removed the RR wheel for ease of access in running the cable. It took a couple of wire ties to get up and over the rear wheel-well but mostly the 4 AWG cable just lies nicely inside the frame beam, very well protected.

I decided it should come out below the rear bumper yet above the trailer hitch. The Anderson SB175 connectors are huge (pic2). A full inch or more of bare wire is required inside each pole connector, so I crimped each in two places. There are a series of holes across the bottom of the rear bumper. I used the two holes closest to the center, fabricated and simple bracket to hold the heavy environmental boot in place (pic3). This worked out great as you can push in and pull out the trailer side connection with one hand and it does not budge! So, I have the trailer harness connection on the left and the DC-DC cables on the right (pic4). It looks clean, nice and balanced.

Many on this forum and elsewhere believe you need both B+ and B- 4 AWG (minimum) wire running all the way end-to-end! This is certainly true for the B+ cable. For the B- cable, I merely ran a 2 ft length from the Anderson coupler grounded to the rear frame. I believe an 8” section of steel frame will produce less electrical resistance than 4 AWG copper and testing showed this to be either true or “good enough!” I ran another short 4 AWG ground wire from the B- battery terminal to the front of the same frame member.

Last step was to connect the B+ charger cable and reconnect the battery terminals. I used another 60A MRBF for the main run (pic5). I also ran short cable from the B+ terminal to the alternator (for redundancy, this connects the charger B+ to both the alternator and batteries with new 4 AWG copper). I’ve never seen anybody take these extra steps, but I believe it will provide better charging performance. You’re running 4 AWG everywhere else, but OEM cables from battery to alternator are usually only 6 or 8 AWG and solid grounds are often an automotive issue. BTW, OTT only installs one 6 AWG ground wire for everything running on DC! I added a second 6 AWG ground cable from the negative bus in line to the batteries in a previous upgrade.

This should work great, I really liked how it turned out. I measured carefully and purchased only 65 ft of black 4 AWG wire (not bad for wiring an extended cab long bed pickup truck tow vehicle)! I used all of it, and every run has slack on both ends and the trailer side connector is 6” longer than the standard hitch coupler cable.

I ran thorough testing today and I'm getting 40A charging output with the Cummins diesel running at idle! Yes, engine running at idle. I captured pictures of all the Victron Connect screens showing Orion and Smart Shunt data. I'm getting rather tired tonight, so to do this reporting justice I'll get all my data together and add another post tomorrow. As I opened my thread above, "this charger setup is awesome!"  

[Ronbrink]

Excellent write-ups on your DC-DC install! Looks like you have it dialed in for peak efficiency, waiting to learn more on its awesomeness! I too ‘home shop’ for spare parts and materials to complete any given project, definitely saves time and money. When I did the alternator upgrade on my former TV (Mechman 320 Amp High Output Alternator) I installed the Big 3 wire upgrade, which substantially improves grounding at the alternator, engine and frame using 1/0 cables. However, I have since stripped said alternator and cables from the Silverado 1500 for future install on the Savana 2500, which has a 150 Amp stock alternator that will suffice for now. I’ve already done the same with the formerly installed DC-DC cables on the Silverado and the Savana is now readied with the rear bumper Anderson SB120 connector and Source Side Environmental Boot/Cover. 

Edited March 22 by Ronbrink

[jd1923]

At start of the performance test, the 600AH Epoch Essentials LiFePO4 batteries were at 100%, rooftop solar sitting in the midday Arizona sun. So, I started the A/C on inverter. It was a mild day low 60s. I set the thermostat down to 55F, opened the windows so no cold air would collect inside and just 34 minutes later SOC was down to 86%, with the old compressor of the noisy Dometic PII running continuously.

I also warmed up the tow vehicle and after 25 minutes idling the gauges looked like this (pic1). Engine Coolant Temp (ECT) was up to 160F (190F is fully warmed up). The idle engine speed at 800 RPM and battery voltage held steady at 14.1V. I did not take a second picture but when the truck was connected to the DC-DC charger, voltage read 13.8V on this gauge.

At first I had configured MAX charge to 30A and took a reading and quickly reconfigured it to the default 50A max charge. Below are the two screenprints, shown left to right (pic2). Set at 30A MAX, 30A was received and 30A also in output. Set at 50A max, the charger output was 40A. This must be due to the 800 RPM idle speed. At highway speeds, the Cummins is generally about +/- 1900 RPM so the HD alternator should produce both higher voltage and amperage.

Again, voltage measured at the truck was 13.8V and when the charger was set for a 30A it read incoming voltage at 13.6V, a -0.2V voltage drop. When producing 40A, the Orion read 13.2V, a -0.6V drop. Is this voltage drop along the wiring?

And I do not understand the lower voltages produced on the output side, as I would think the Orion charger would output higher voltage in the range of 13.6V to 14.2V to the batteries. Maybe Geoff @Snackchaser knows, how does this makes sense? The 30A charge looks fully efficient. Set at 50A I got 40A idling at 800 RPM. The final test, I will run start of your next trip, will be to test the 50A charge setting at highway speeds. All this was done sitting at idle in my driveway. More to come…

[jd1923]

I needed to verify numbers showing for the Orion Charger are relative to what the Victron Smart Shunt was reading at the batteries. The screenprints (Orion vs. Shunt) were as follows (pic1). Why does the Smart Shunt showing 10A more? Because the Blue Sky solar (pic2) was adding +12A and the remainder -2.3A is used for inverter standby overhead, exterior Courtesy Lights (always on) and some parasitic. These numbers add up nicely!

[jd1923]

Last test for now...

What if when boondocking, far from hook-ups and other campers, you're needing A/C on a HOT afternoon, and your batteries getting low? You could start and connect the tow vehicle to the DC-DC charger. Diesels can idle forever using little fuel.

The truck alternator via the Orion charger could supplement inverted power to the A/C for some period of time. The approx. +40A noted before at idle should offset the AH used by the A/C system. These readings (pic1) show this to be true, +39A were being supplemented by the charger at this point in time - nice!

Also notice, the Time Remaining stat increased from 2 1/2 hours to 4 hours given the lower AH usage. I will eventually install an A/C that uses much less power than the Dometic PII. That's all folks.

Edited March 22 by jd1923

[johnwen]

thumbs up!

[John Dorrer]

JD, This is way overy head. I'm actually having a good chuckle

 I want to see all of this when we see each other next. 😊👏👏

[jd1923]

2 hours ago, John Dorrer said:

I want to see all of this when we see each other next. 😊👏👏

Yes John, you and Susan, and your wonderful, infamous Jolli Olli, please come see us on your 2025 western trip!

We have power and water hook-ups for those who are off-grid challenged 🤣, and a dump station just down the steet!

It would make our day, no, it would make my year to see Y’all in Prescott Arizona! God bless

Edited March 23 by jd1923