Victron DC-DC Battery Charger

DenisP

I just finished installing a Victron Orion 12-12 30A Battery Charger in my 2018 Tab 400 with factory solar.  After our last camping trip which was three nights of dry camping at a state park with a partially shaded site and had a couple overcast or rainy days which the rooftop solar panels nor the 100 watt solar panel brought the State of Charge up to 80%.  I had reviewed several DC-DC chargers but decided on the Victron as I have a Victron solar controller and battery monitor and use Victron Connect to monitor my charging status.  The 30 A charger has bluetooth interface into Victron Connect for monitoring/setup and has auto-detection of vehicle running which will shut off charger and isolate current draw from the tow vehicle.  The installation was pretty straight forward complicated by the battery placement in the 400, probably much simpler in a 320.  Looking forward to a fully charged battery between sites while traveling and being able to top off the batteries using the truck at the campsite.

JeffroNC

@DenisP
This makes a lot of sense. How did you run the cables from the plug to the controller? Can you share a materials list?

DenisP

@JeffroNC In the bottom of the closet there is an access hole for a ground wire which was large enough to snake two 6 gauge wires.  I opened the belly pan from just behind the wheel to the tongue on the driver's side and then followed the path of the 7 pin wire to the front of the trailer.  The wiring is listed in the parts list which is 6 gauge welding wire which has a tough insulation.  Once I was sure I had enough length to easily reach the anderson connector on my truck's bumper, I ran the other end into the "Alde compartment" through an access hole for Pex tubing from the closet floor.  I left enough slack to be able to work on wiring the battery charger from in front of the bed (extra 18").  I snaked two wires into the center under bed compartment and under my inverter to reach the battery terminals.  I connected to the negative pole on the BMV 712 shunt and the positive battery pole on the outside of the battery box.  The positive lead was first attached to a 60A fuse using a fuse holder.
Parts List (with some links)

• Victron Energy Orion-Tr Smart 12/12-30A Isolated DC-DC Charger with built-in Bluetooth (ORION-TR SMART 12/12-30A)
• Victron Energy Fuse holder for MEGA-fuse
• Victron Energy MEGA-fuse 60A/32V
• #6 wire x 3/8" stud ring connector terminal, non-insulated
• https://www.amazon.com/dp/B07V6V7XZC/ref=cm_sw_em_r_mt_dp_3lRMFbSKYK2WH?_encoding=UTF8&psc=1
• https://www.amazon.com/dp/B00LIB8C32/ref=cm_sw_em_r_mt_dp_ElRMFbY2QFWE4?_encoding=UTF8&psc=1
• https://www.amazon.com/dp/B07CSKB9C3/ref=cm_sw_em_r_mt_dp_HkRMFbNQMEQ2X?_encoding=UTF8&psc=1

A helpful youtube overview of the Battery Charger and The Datasheet with wiring diagram.

• https://www.youtube.com/watch?v=vBL9vueSv6s&t=498s
• https://www.victronenergy.com/upload/documents/Datasheet-Orion-Tr-Smart-DC-DC-chargers-isolated-250-400W-EN.pdf

I also wired my truck with the same 60 amp fuse and holder with the 6 gauge wire terminating with an Anderson connector on the bumper near the 7 pin trailer connector.
Hope this helps,
Denis

rhyno

@DenisP - Nice setup and thank you for the guidance. I'm trying to figure out how to make this into kind of a multi-tap solution. How difficult would it be to add an additional wiring harness feeding into the Orion-Tr charger in order to charge directly off of a generator, bypassing the direct tap running from your truck? Would it be best to just add a distribution block before the charger to accommodate the additional wires?

Tabnero

explain to me why you wanted to do this dc to dc charger? what are you gaining over 7 pin wire harness to tab that charges the battery going down the road?

4ncar

Tabnero said:

explain to me why you wanted to do this dc to dc charger? what are you gaining over 7 pin wire harness to tab that charges the battery going down the road?

The tow vehicle is not producing enough voltage/amperage to recharge or fully charge his trailer batteries while in motion.

Tabnero

ok

DenisP

@rhyno I did run a new 6 gauge wire from my TV battery which connects to the Tab 6gauge wire to the battery charger. For two reasons, one while there is a gain from the 7 pin connector- the wire is a smaller wire which promotes a power loss and two the battery charger will provide three stage charging to fully charge my batteries. 

I am not a fan of generators and if I can quietly top off my batteries when needed without a generator and auxiliary gas cans I am happy. My main goal is to arrive with topped off batteries when traveling. 

JeffroNC

@DenisP Thanks for the details. I can see my generator becoming a thing of the past.

Tabnero

I just dont have this issue with Battle Born Lithium and 160 Watt zamp solar panel

CrabTab

Nice screenshots and pics @DenisP. Thanks.

m_lewis

@Tabnero, I can't speak for @DenisP, but I can relate couple of good reasons to add this device. 
1. The wires in the 7-pin are at best 10ga, leading to significant voltage drop over the distance from the TV to the 400's batteries. His TV may or may not have an AGM battery, but even if it does, and his alternator keeps it perfectly charged, by the time the current gets down those skinny wires it is not going to be at a high enough voltage to promptly and full charge the camper's batteries. Plus, this device is capable of stepping up the voltage from the TV to the perfect voltage for the camper.
2. It is a 3-stage charger, capable of being configured precisely to effect maximum battery life with the shortest charge cycles, thus higher efficiency. 

Even using shore power or a generator, the WFCO convertor is a poor choice for properly charging AGM batteries, as its voltages are set too low. The solar option allows full charge parameters to be configured in the Victron MPPT device, but he was in a shady spot, so solar did not help much.

I am glad you do not see the need with your Battle Born and external solar setup, but there tends to come a time when the sun doesn't shine and the need for fossil fuel becomes powerful. I think this will soon be another mod to our camper, before we take off on a long trip.

4ncar

I thought I was going to need to do this mod or something similar, but it seems my truck is one of the few that has an alternator/ecu that can keep up with the battery draw on my 32s with the 3way fridge running. I was worried, but confirmed all time  well one I installed the bmv and could monitor real with the Bluetooth app. 

DenisP

@4ncar the infrequent issue I was addressing with the charger, is if the Tab’s batteries State of Charge (SOC) drops while camping and the solar gain from the 200w roof and the 100W Renogy suitcase do not fully replenish the SOC.  My truck has no problem maintaining whatever SOC the Tab with 2 way fridge is at when departing but it will not gain if the SOC is depleted.  I have been researching this mod for a while and the benefits for my camping needs outweigh the cost.  This certainly may not be for everyone.
Benefits:
3 stage charging with voltage and amperage based on the batteries charging needs to fully charge the AGM batteries
Larger wiring to batteries/charger are an improvement over the voltage/amperage loss with smaller wire through 7 pin connector
The ability to (quietly) charge the camper if needed during poor solar gain and to fully charge the batteries while under tow to make up for lower SOC.

4ncar

@DenisP: I am not discounting your reasoning, just pointing out that I had considered similar(and May still do so) for a condition that many experience. I may find, as you have that the dc-dc charger is a necessity for the type of camping I intend to do, but so far not as yet.

Tabnero

the alternator on my Colorado puts out a 14.7 at times. so even if the battery is only moderately charged while going down the road, there has not been a time I could not top off with direct to battery clips from solar panel. If I start to have a problem, the solution here will be investigated. Many thanks

Denny16

I also got some inadvertent boondocking in, when PG&E shut off the power during a recent Red Flag Fire Alert whilst on ourbrecent camping trip at a Lake side resort.  The TaB solar panel was partially in shade morning through  mid day, and less so in late afternoon, and the solar kept up with the two way fridge, and the battery went from 85% after powering the trailer all night, using the Alde in gas mode, fridge running and lights used, and recharged to around 96-97% during the day.  The battery returned to 100% charge during the trip home with a sunny day.
cheers 

Ron

DenisP,  I did the exact same thing on my 2018 Jeep Wrangler and 320 with two 6 volt golf cart batteries.  I arrive in the afternoon with a charged battery.  I used the Redarc 12v-12v charger.  I do wonder what might be happening when the trailer battery is at 14+ volts and the Jeep is going uphill and the alternator drops to 13 volts.  Is there a possibility of the trailer back feeding the jeep battery?  If so, would it even matter?  I believe that sway control ect, is turned on in the tow package by the draw on the hot 12 volt line to the trailer that is meant to charge the breakaway battery.  If you don't get a 1.2v delta the current won't flow anyway.  Just not sure about all the integrated electronics in newer vehicles.  The larger wires used to feed the 12v charger have lower resistance that the small 7 pin connector wire, so I don't think that the charger set to 25 amps will overload the small original wire.  I have considered disconnecting the 7 pin 12v wire, but if it ain't broke don't fix it.  Electrical engineers feel free to chime in.

CharlieRN

Ron said:

DenisP,  I did the exact same thing on my 2018 Jeep Wrangler and 320 with two 6 volt golf cart batteries.  I arrive in the afternoon with a charged battery.  I used the Redarc 12v-12v charger.  I do wonder what might be happening when the trailer battery is at 14+ volts and the Jeep is going uphill and the alternator drops to 13 volts.  Is there a possibility of the trailer back feeding the jeep battery?  If so, would it even matter?  I believe that sway control ect, is turned on in the tow package by the draw on the hot 12 volt line to the trailer that is meant to charge the breakaway battery.  If you don't get a 1.2v delta the current won't flow anyway.  Just not sure about all the integrated electronics in newer vehicles.  The larger wires used to feed the 12v charger have lower resistance that the small 7 pin connector wire, so I don't think that the charger set to 25 amps will overload the small original wire.  I have considered disconnecting the 7 pin 12v wire, but if it ain't broke don't fix it.  Electrical engineers feel free to chime in.

I just ran across this thread and have the same question about the utility of the live 12v connection in the 7 pole connector @Ron. Perhaps my bump will get the attention of the more electrically savvy who will set us straight.

TomCanada

The trailer battery can charge at >14V, but once it's being used as the source, you're rarely going to see anything over 13V.  Likely closer to 12.7V when fully charged.  Charge your battery fully, attach a load, and measure the voltage and you can confirm this..

CharlieRN

TomCanada said:

The trailer battery can charge at >14V, but once it's being used as the source, you're rarely going to see anything over 13V.  Likely closer to 12.7V when fully charged.  Charge your battery fully, attach a load, and measure the voltage and you can confirm this..

I'm new to this but my understanding is that the DC-DC charger moderates the voltage to the trailer battery at all times, keeping the charge levels as close to optimum as possible.

So for example, it increases the voltage to the optimum absorption level for the trailer batery(ies) then reduces it to the appropriate float level. From what I've read, there are significant differences in the absorption and float levels between the starter and trailer batteries, and by optimizing the feed to the trailer battery, the device ensures proper initial and maintenance voltages, and so increases both performance and life.

Is this really the case? If so, it would seem that the DC-DC charger would be beneficial in virtually all situations, regardless of battery type.

DenisP

@CharlieRN That is my understanding and in my short experience (one round trip to Sugarcreek and back to Mass 1300 miles) reflected your summary. I am very pleased with its’ performance and the ability to monitor output/charging stage via Victron connect is a real plus. The setup works great with the AGMs in my 400 and I would expect no different with Lithium or flooded acid as the charge profile is customizable based on battery needs. 

CharlieRN

@DenisP - thanks. There are some aspects of connecting a charger that are still murky to me however.

Regarding the connection from the TV alternator to the charger, this looks like it is  direct via the appropriate gauge (8 or even 6 awg) wire. So you connect directly from the starter battery (via breaker) to the charger and then to the trailer battery. This would seem to render the 12v feed between the starter and trailer batteries via the 7-pole harness redundant or maybe even harmful.

I think this is the question that you asked (& that I quoted above) but did not seem to see answered in the thread.

DenisP

@CharlieRN My connection is a 6 ga from the TV battery with a 60a fuse to an Anderson connector at the rear bumper. At the Tab, 6 ga wire runs from the Anderson connector along the frame and under the Coloplast bottom to an access point in the closet (where a ground wire goes through the floor) and back to the dc/dc charger which I mounted near the solar controller in the Alde compartment. From the dc/dc charger,I ran 6ga wire to another 60 amp fuse at the battery.
this does represent a redundant 12v lead from the TV counting the 7 pin but I don’t believe it is an issue. 

MarkAl

This may have been mentioned above but this will also if using a higher voltage battery (Lithium) in the trailer decouple the car's lead-acid lower voltage system from the trailer so potentially the trailer won't power the car's electrical system. Also potentially the solar chargers won't attempt to overcharge the car's battery while connected.

WY320Camper

Great thread here that I'm interested in doing for my set up. I have a 2013 Ram 2500 Tradesman truck with a 180Amp alternator with my 2020 T@B Boondock Edge with factory solar.
 
Purpose is to travel and keep electrical power to heaters keeping tanks/valves/lines from freezing, then once camped in below freezing temps run propane for Alde and other systems. So here is my plan:
1. Will be doing the TABZ mod for heating and enclosing tanks/dump valves.
2. Will be adding low amp draw electrical heaters for when towing. ETrailer has         several sizes for tanks/valves/lines. 
3. Upgrading battery to 2 6v batteries in a insulated battery compartment mod.
4. Add extra solar panel(s) which will be mobile to boost daily recharge.
5. Run generator as needed. Hopefully not much if at all.
 
Any advice on doing the electrical will be helpful.