More DC to DC charger installation tidbits

[Snackchaser]

I just completed installation of a Victron Smart Orion 30 amp isolated DC to DC charger after reading all the great information provided in this forum by MAX Burner, and others.  I really appreciated all their groundwork and details, so I wanted to share some of my experiences in the hope that others will find it useful.

I used #4 AWG wire for ease of installation and for better termination options.  BatteryCablesUSA recommended their “Jumper Cable” wire and it was the best deal I found at $197 for 55’ x 2.  It consists of a black and red cable joined together like zip cord, and it’s flexible enough to lay flat under it’s own weight.  Their lugs and heat shrink were also reasonably priced.  I sheathed the full length of the cable with 3/4” braided cable sheath for extra protection and good looks (Amazon Keko 100’ roll for $21.)  I seized the ends with Amazon XFasten fabric Wire Harness Tape (5 rolls for $14.)

BatteryCablesUSA also recommended Anderson SB50 connectors, instead of the larger #4 AWG rated SB120 connectors that I originally planned.  They said that #4 AWG wire would fit in the SB50 #6 AWG contact pins, which it did.

I used Trailer Vision covers for the Anderson SB50 connectors.  A TV-201426-50 surface mount receptacle with hinged cover plate was installed under the truck bumper.  It has a red LED power indicator that I discourage from connecting because it’s on all the time and annoyingly bright.   They also offer a flush panel style mounting.

The sheathed cord on the trailer side got the Trailer Vision TV-328993-50 plug cover.  It has a protrusion that catches on the mating receptacle’s hinged cover to stop it from pulling out.  It’s similar to how the 7-pin connector ports hold the plug in.  It also has a LED power indicator that’s more useful because it’s only on when connected.  It uses a compression gland for the cable that I filled with black RTV.

Powerwerx company sells Trailer Vision parts, Anderson connectors, and other accessories for reasonable prices.  Get at least 4 extra #6 Anderson pins for connecting to the Victron compression terminals as explained later.  Powerwerx also sells the “PanelpodSB,” which is a surface panel mount Anderson SB50 housing for $11.99.  I mounted one on the Oliver’s cargo box for “parking” the Anderson connector when it’s not plugged into the truck.  It keeps with my existing theme of parking places for the 7-pin cable and RAM rear view camera cable.  They also sell a tethered cap to keep it clean when traveling.

The engine compartment wiring was straight forward.  I connected the cable’s red wire to a 60 amp terminal post fuse on the battery positive.  The black wire terminated to the battery negative.

The trailer half of the sheathed cable went through a penetration behind the LP tanks.  A hole was drilled through the trailer wall next to the existing penetrations with a 1-1/8” step bit.  The sheathed cable passed though an Amazon PA66 1” nylon cable gland ($7.99 for two.)   I used a short piece of heat shrink over the sheathing where it passed through the gland and filled the gaps with black RTV.  The shelf under the bathroom sink has to be removed for access to the inside cable penetrations.  From there the cable can be simply pushed under the floor to the rear dinette seat where the Victron was mounted.

The Victron has some great safety features that will automatically reduce, or shutdown, the output if it gets too hot or the input voltage drops too low.  It’s important to take this into consideration because it would likely happen while driving, and you wouldn’t know it without constant monitoring.

Voltage drop especially comes into play with the new smart alternators that lower voltage output to save energy.  The Victron’s default voltage settings account for this.  However, due to the longer run of cable needed with travel trailer installations, the cable resistance can cause enough voltage drop where it can go below the default settings and cause the Victron to derate it’s output.

I calculated the voltage drop for different wire gauges at 35 amps (nominal input current) and a cable distance of 53’ x 2.  The results don’t include the connector and termination losses:

1.46 volt drop for #6 AWG

0.92 volt drop for #4 AWG

0.58 volt drop for #2 AWG

Per Victron’s instructions, a 0.6 voltage drop can cause a “Voltage Lockout” with the default settings.  There are many factors that can affect this, and fortunately the Victron defaults can be adjusted.  To account for my voltage drop, I decreased the “Start Voltage” from 14 to 13 volts, and the “Shutdown Voltage” from 13.1 to 12.8 volts. These setting were recommended by “Offgrid Power Solutions,” on a You Tube video called “Victron Orion-Tr Smart DC-DC Charger settings.”

Cooling is also an important consideration for the Victron because they create a lot of heat, and they derate charging current 3% for every degree above 104⁰ F.  That’s almost 50% performance loss at only 120⁰.  Maximum operating temperature is 131⁰, where I believe it shuts down completely.   This is why I installed cooling fans (but also for the fun of it.)

Amazon’s ”Sound Original” low profile blower fans (two for $9.99) were the right size, they had bearings, brushless motors, and a good mounting configuration for this application.  The Victron was mounted on 1/4” standoffs to keep its cooling fins off the mounting surface, and it also helps the fans to distribute air more evenly.  I used a Normally Open, 104⁰, 5 amp, thermostat switch to control the fans (Amazon Uxcell KSD9700 (2 for $5.49).  The fans get power from the input terminals on the Victron so they can only come on if the truck is connected, and the temperature is over 104⁰.  The thermostat switch resets at 86⁰.

The Victron was mounted on a painted plywood board that was attached to the forward battery compartment wall.  It’s an easy to reach, out of the way location.  I used 4 rubber well nuts that stay in place by themselves, but regular nuts and bolts could be used.

The sheathed #4 cable was terminated to the Victron’s input compression terminals, with the fans power leads.  I struggled at first with the Victron’s compression terminations, the wire wouldn’t fit, and I couldn’t find #4 square ferrels.  So I was pretty pleased to discover that Anderson pins can be filed down to fit perfectly.  Just be sure to cover the exposed barrels with heat shrink.

The negative output of the Victron went to the main chassis ground post under the rear dinette seat where there is a 2/0 cable going directly to the battery negative.   The positive output was connected to the line side of a Blue Seas 60 amp fuse block, from there it went to the line side of the existing inverter’s DC circuit breaker, which is jumpered to the battery positive with a 2/0 cable.

With the TV at idle and the lithium batteries around 60%, the Victron output was 35.8 amps as measured by a clamp-on amp meter.  The TV input was 42.5 amps.  This calculated to 84% efficiency, which is close to Victron’s 87% claim, which I assume is under perfect conditions.

I really liked the looks of the sheathed cable and Trailer Vision plug and receptacle,.  The hinged receptacle cover will keep the dirt out when not towing.  The plug and receptacle are locked together more securely with the Trailer Vision covers, otherwise the Anderson connectors can be fairly easily pulled apart and they might not stay together on a bumpy road.

Cheers, Geoff

[mossemi]

@Snackchaser WOW!  Great write up and execution.  Thank you!

Mossey

 

[topgun2]

5 hours ago, mossemi said:

WOW!  Great write up and execution.  Thank you!

I'll second THAT promotion!

Bill

[Carl Hansen]

This was great!  This is just what I was looking for.  Can you expand a bit on how you routed the cables back to the batteries?  Did you use a fish cable or were you able to just "push" them through.  This is a much better solution to running them outside underneath the chassis.

Thanks!

[jd1923]

12 minutes ago, Carl Hansen said:

Can you expand a bit on how you routed the cables back to the batteries?

Make sure you purchase the Orion XS 50A charger that was not yet on the market when Geoff worked his install. I detailed my installation and charging performance. We love it, no more SOC% worries. Watch video to see why to spend on the 50A model and check out other installations. See mine below and there are at least 4 on this forum (search for Orion or DC-DC).

[Coddiwomple]

Hey Carl, you can come over to see how I did mine in our Elite 1 if you like.  I don't know if you remember me and Martha but you showed your Elite 1 to us on 9-3-22 when we were considering an Oliver.  We are in North Plains. 

[routlaw]

Interesting write-up and execution, well done.

However I am stumped as to why you or anyone would go to so much trouble and expense to charge your RV batteries from the tow vehicle? Not meant to be derogatory just don't understand why. From videos I have seen from Will Prowse he is thumbs down for using your tow vehicle to charge RV batteries. Now that I have installed LiFE-PO batteries I was considering removing my relay switch and fuse that controls battery charging from the tow vehicle actually. 

What am I missing? Thanks

[Carl Hansen]

57 minutes ago, Coddiwomple said:

Hey Carl, you can come over to see how I did mine in our Elite 1 if you like.  I don't know if you remember me and Martha but you showed your Elite 1 to us on 9-3-22 when we were considering an Oliver.  We are in North Plains. 

That would be amazing.  I will send you a message.

[Carl Hansen]

17 hours ago, jd1923 said:

Make sure you purchase the Orion XS 50A charger that was not yet on the market when Geoff worked his install.

Thanks for the links!  When I first began my research, I thought the 30A Orion would be the solution.  Since then, with all the videos that I have watched, and what the lithium batteries are capable, it became clear that the 50A Orion was a much better solution.  That is what is on my shopping list along with 4 gauge wire, etc.  Your suggestion is yet another confirmation that the 50A is the right solution.  Now if I can get past the worry of pulling all these wires properly and getting through the hull, I will pull the trigger on my shopping list.  I can always find something to worry about!

Carl

[jd1923]

10 minutes ago, Carl Hansen said:

Now if I can get past the worry of pulling all these wires properly and getting through the hull…

Glad for you that David @Coddiwomple reached out. I could not answer for an EI.

Also check into the amperage capability of the alternator on your Jeep. Some of us have had to upgrade that to guarantee available amps.

[Carl Hansen]

48 minutes ago, routlaw said:

Interesting write-up and execution, well done.

However I am stumped as to why you or anyone would go to so much trouble and expense to charge your RV batteries from the tow vehicle? Not meant to be derogatory just don't understand why. From videos I have seen from Will Prowse he is thumbs down for using your tow vehicle to charge RV batteries. Now that I have installed LiFE-PO batteries I was considering removing my relay switch and fuse that controls battery charging from the tow vehicle actually. 

What am I missing? Thanks

I have consider DC2DC charging for the last 4 years.  I wanted to consider how we use the trailer before installing the DC2DC charging.  We do longer trips and often stay at Harvest Host along the way.  It's nice to pull into a dry camping spot with a full charge on the batteries.  The solar does a pretty good job but not during the night and decreases effectiveness in bad weather.  

The following reasons made me decide to pursue DC2DC charging:

1. You got a guaranteed output of up to 700 watts, rain, night, it doesn't matter

2. Additional panels on the Elite 1 is not an option.  DC to DC is like adding additional solar panels to the rig.

3. How about portable panels? Portable panels are heavy and do not store well.

4. Portable panels only work during the daytime.  We are on the road most days.

5. Portable panels won't run the air conditioner. I do carry a portable generator with us which can run the air conditioner if necessary.

6. DC2DC is guaranteed output.  It is going to work all the time. (Maybe a duplicate of #1 but I think it is worth mentioning again.)

I think it depends on how you use your rig.  If you always stay at places with shore power, maybe the DC2DC charging doesn't make sense.  I believe the decision to install DC charging depends on your use model.  It may not make sense for everyone.

Carl

[Carl Hansen]

12 minutes ago, jd1923 said:

check into the amperage capability of the alternator on your Jeep. Some of us have had to upgrade that to guarantee available amps.

The 2020 Jeep Gladiator Rubecon has a 220 amp 'smart' alternator.  From what I understand, that should be sufficient for DC charging.  That is an important consideration.

[topgun2]

Carl - 

I assume that you have viewed THIS thread that has several relevant post to what you are doing/thinking.

Specifically - the KYD install of a DC to DC system on their rig.

Bill

[Carl Hansen]

I did and found some great tips in that video. They make a case for DC2DC charging as well. That video helped my wife better understand the value as well. 
 

Thanks!

[jd1923]

4 hours ago, Carl Hansen said:

The 2020 Jeep Gladiator Rubecon has a 220 amp 'smart' alternator.  From what I understand, that should be sufficient for DC charging.  That is an important consideration.

You are golden! My old Ram had 130A OEM, I replaced with a HO 180A and I’ve gotten as high as 48A outputted from our Orion XS 50A charger.

[MAX Burner]

On 5/14/2025 at 10:49 AM, Carl Hansen said:

I think it depends on how you use your rig.  If you always stay at places with shore power, maybe the DC2DC charging doesn't make sense.  I believe the decision to install DC charging depends on your use model.  It may not make sense for everyone.

Carl, IMO, you're spot-on, brother!  Modifications, upgrades, and otherwise enhancements outlined in various levels of detail in this forum are for information purposes and general "better" understanding of what the OTT can do during our collective travels.  That said, our "collective travels" are widely different across the spectrum of owners.  Everyone has their own "style" of camping with their Ollie - some fancy established RV parks with full connections for the majority of their travels, others prefer full-on off-grid boondocking for most of their trips.  The rest of the owners likely fall in between these extremes. 

So, depending on what "style" of camping you prefer, would dictate which mods suit your purpose of camping.  But that's what's so phenomenal about this forum, there's such a wide spectrum of experience and expertise here, one can choose the mods fitting their camping style the best.  

The discussion about DC2DC chargers are such an example.  It's not a "one size fits all" issue, if you catch my drift....

[Carl Hansen]

Well, I pulled the trigger today and ordered all my DC charging parts.  They will be coming in over the next week or so.  I would like to extend a big thanks to all the members of this forum, who over the years, have helped me with many questions and concerns  I would like to give a special thanks to Coddiwomple (David) who graciously invited me over to his shop to show me how he installed his DC charging in his LE1.  It was extremely helpful to see first hand.  He went beyond the mark by opening up his TV and trailer (including every access panel) and allowed me to photograph and video his trailer. He even went so far to give me copies of all his documentation and notes.  It's people like David and many others that make this community such a great place to communicate and share.

Thanks to everyone!

Carl

BTW... I just got notified by Highway Trailers in Salem that Oliver is sending them the Truma water heater parts replacement for the recall.  There is hope!

[Ronbrink]

On 5/14/2025 at 10:41 AM, routlaw said:

Interesting write-up and execution, well done.

However I am stumped as to why you or anyone would go to so much trouble and expense to charge your RV batteries from the tow vehicle? Not meant to be derogatory just don't understand why. From videos I have seen from Will Prowse he is thumbs down for using your tow vehicle to charge RV batteries. Now that I have installed LiFE-PO batteries I was considering removing my relay switch and fuse that controls battery charging from the tow vehicle actually. 

What am I missing? Thanks

 As expressed by others, it’s really a matter if choice. Since I don’t have solar, the DC-DC allows for charging while underway. Since upgrading to LFPs and the ability to run the air conditioner on the battery bank, it was important to me to be able to maintain adequate SOC following travel breaks during meals, rests and such while drawing down the batteries for this added comfort. Granted, sitting idle just to charge a battery bank is not practical, and disconnecting the TVs charging wire in the seven pin connector is best since the alternator’s charging profile is not suitable for lithiums.

Edited May 17 by Ronbrink

[jd1923]

7 hours ago, Ronbrink said:

Granted, sitting idle just to charge a battery bank is not practical…

But could be in a pinch. I get 40A when idling, and with a diesel you can idle long, as long as you’d stand hearing the engine. Under idle, we can run A/C at 60% consumption, and if I had the wonderful Atmos unit Ron has it would be closer to 40%!

[Jason Foster]

19 minutes ago, jd1923 said:

But could be in a pinch. I get 40A when idling, and with a diesel you can idle long, as long as you’d stand hearing the engine. Under idle, we can run A/C at 60% consumption, and if I had the wonderful Atmos unit Ron has it would be closer to 40%!

Don’t forget, the new diesels, if not deleted, will delete themselves if you idle too long. My 6.7 is deleted and will idle for extended periods of time without harm but the new ones will clog up all the EPA garbage. 

[jd1923]

13 minutes ago, Jason Foster said:

Don’t forget, the new diesels, if not deleted, will delete themselves if you idle too long. My 6.7 is deleted and will idle for extended periods of time without harm but the new ones will clog up all the EPA garbage. 

Yes for sure. Our 2001 first twin valve Cummins, no DEF, no BS, can idle all winter!

[Jason Foster]

3 minutes ago, jd1923 said:

Yes for sure. Our 2001 first twin valve Cummins, no DEF, no BS, can idle all winter!

The way trucks are meant to be. 

[Ronbrink]

9 hours ago, jd1923 said:

But could be in a pinch. I get 40A when idling, and with a diesel you can idle long, as long as you’d stand hearing the engine. Under idle, we can run A/C at 60% consumption, and if I had the wonderful Atmos unit Ron has it would be closer to 40%!

Thanks for the reminder that diesels rock when it comes to idle abilities! However, not practical from this gasser’s standpoint, at least when sitting idle for extended periods just to fully charge and no other purpose. Good point on a/c consumption being offset by power input from a DC-DC, idling or underway! I oftentimes let my COW cool down before a scheduled stop, especially when traveling in extreme heat conditions. Before LFPs my original Renogy 20A charger did justice to the four 6V Trojans, but I had to break out the generator for added comfort during stops. I quickly learned once the switch was made to lithiums and changes to run the a/c on batts that a larger charger was needed and thus, a 40A was installed. And yes, upgrading to the Atmos made things even more better!