Victron DC DC charger?

[John in Michigan]

Any experience or opinions re the Victron Energy Orion-Tr Smart DC-DC Charger (Isolated)?

Background:

I recently incorporated a Lion Energy 100 amp hour LIFEPO4 battery and a Propex HS2800 propane furnace into the Boler 1700. These items together with the propane fridge (no electricity required) are used for dry camping.

Already had GOOD experience with that battery AND furnace while dry camping in October 2020 in Michigan for four nights. We experienced sub freezing temperatures each night and daytime highs around 45F. We were field testing TWO items for the first time: the LIFEPO4 battery together with the Propex furnace. We had also set up a 100 watt solar panel with a Victron MPPT solar charge controller, however due to short daylight hours, cloud cover and dense tree cover there was VERY LITTLE solar power generated. At the end, we found that the fully charged battery was STILL able to power everything four days and four nights, with 40% battery remaining!

Question:

Would a Victron DC DC charger powered from the tow vehicle help us camp longer with those dry camping/low solar days? I am planning do this by moving the 23 pound battery from the trailer to the tow vehicle, and then charge it during our daily sightseeing, then move the battery back to the trailer. Might also purchase a second LIFEPO4 battery. Again these batteries are 23 pounds each.

[Jon Vermilye]

I use a Victron 9 amp DC to DC controller between the tow vehicle & the trailer equipped with two Battleborn batteries. Since I have 480 watts of solar, I didn't need a larger controller. I added it to increase the tow vehicle voltage to 14.4V for the lithium batteries, and a secondary reason - to prevent the lithium batteries from discharging into the tow vehicle battery. The DC to DC controller also can prevent overdrawing current from your alternator; sometimes a problem with motorhomes & truck campers, but, with the long wire runs for trailer, rarely a problem for them.

One consideration. The DC to DC controller is a one way device. If you put it in the trailer on the battery side of the breakaway switch connection, you will no longer have a connection if the trailer separates from the tow vehicle. In my case I added a separate wire from the batteries to the breakaway switch (and power tongue jack).

[John in Michigan]

"One consideration. The DC to DC controller is a one way device. If you put it in the trailer on the battery side of the breakaway switch connection, you will no longer have a connection if the trailer separates from the tow vehicle. In my case I added a separate wire from the batteries to the breakaway switch (and power tongue jack)."

Jon, I am planning to install the DC DC charger in the tow vehicle. Then IF we are camping in a low sunlight situation such as what happened in October, I will charge the 23 pound Lion Energy battery by moving it from the trailer to the tow vehicle, and then charge it during our daily sightseeing, then move the battery back to the trailer. I can also if necessary charge the battery in the tow vehicle while travelling between camping destinations. We are not full timers, and don't use our trailer for months at a time, so I don't leave the battery in the trailer for extended periods. Does this make sense to you?

[John in Michigan]

Jon, I also agree with your point that an advantage with the DC DC charger is that it provides the constant 14.4 volt charging level. This is especially important since newer tow vehicles like mine incorporate smart alternators with wide voltage fluctuations. The Victron DC DC Charger apparently addresses this voltage fluctuation by sensing alternator voltage changes and automatically starts charging when the alternator voltage rises above a preset threshold, and then stops charging when the alternator voltage drops below the threshold. The specifics of how this works are found in this Victron document:

https://www.victronenergy.com/upload...Charger-EN.pdf

[John in Michigan]

At our 4 day/4 night dry camping trip in Michigan in October 2020, the solar opportunities were so poor that with our 100 watt solar panel coupled with a Victron MPPT solar charge controller and moving the panel to follow the sun, we only got about 2 amp hours of power over four days! I was able to view the cumulative charging info on my Victron bluetooth phone app.

Friends that were with us on that trip were also solar charging with at least 300 watts of solar panels that they were moving to follow the sun. They had similar bad luck.

[Marv]

Jon,
How do you prevent overcharging on a long drive? As I understand it that model is not smart, just puts out its steady rated current continuously.

[John in Michigan]

The Victron Energy Orion-Tr Smart DC-DC Charger (Isolated) line of chargers are smart chargers. I am considering the 12/12-18 model. Here is an overview from the Victron website:

Adaptive 3-stage charge algorithm: bulk – absorption – float
• For lead acid batteries it is important that during shallow discharges the absorption time is kept short in order to prevent overcharging of the battery. After a deep discharge the absorption time is automatically increased to make sure that the battery is completely recharged.
• For lithium batteries absorption time is fixed, default 2 hours.
• Alternatively, a fixed output voltage can be chosen.

You either use the default charging algorithms or customize as you see fit. Much more information is provided here:

https://www.victronenergy.com/dc-dc-...orion-tr-smart

[Jon Vermilye]

Originally Posted by Marv

Jon,
How do you prevent overcharging on a long drive? As I understand it that model is not smart, just puts out its steady rated current continuously.

I have a switch in the trailer that I use to disconnect it. I only use it if the batteries are down & I'm driving. While ZI don't depend on it, it appears that the BMS in the batteries will limit charging current when the batteries are full.

[sokhapkin]

Victron devices are good, but are extremely overpriced. Take a look at Renogy DC to DC chargers, they are much more affordable.

[John in Michigan]

Originally Posted by Jon Vermilye

I have a switch in the trailer that I use to disconnect it. I only use it if the batteries are down & I'm driving. While ZI don't depend on it, it appears that the BMS in the batteries will limit charging current when the batteries are full.

Jon,

- Yes the LIFEPO4 battery BMS will protect the battery, so overcharging is not a problem for LIFEPO4 batteries.
- The Victron product line that I am looking at, the Victron Energy Orion-Tr Smart DC-DC Charger Isolated has default smart charging profiles for wet lead acid, sealed lead acid (gel and AGM) and LIFEPO4 batteries. Also these products provide the ability to adjust the default profiles and add custom profiles.
- This product line will automatically sense that the tow vehicle engine is ON and start charging, and OFF and will stop charging.
- I couldn't think of anything the product line couldn't do.

Also, keep in mind that Victron has related product lines, past and present, including the DC DC Converters. I have not investigated the capabilities of these other product lines.

John in Michigan

[John in Michigan]

Originally Posted by sokhapkin

Victron devices are good, but are extremely overpriced. Take a look at Renogy DC to DC chargers, they are much more affordable.

Sergey, I found:

- Renogy 20A DC to DC Battery Charger for $108.47 on Amazon
- Victron Energy Orion-Tr Smart 12/12-Volt 18 amp DC-DC Charger, Isolated (Bluetooth) for $175.18 on Amazon

So yes the somewhat comparable Renogy device that I am also investigating is less expensive. I am trying to determine their various capabilities and what I really want. The Victron device appears to have far more features than the Renogy device.

[bigangelman]

For these issues I check out Will Prowse YouTube videos. Or his Diyourself solar forums.

[Dismantle]

Wondering how I wire the trailer with a 7 pin? I don't want to cut the lights and other 7 pin features. Just want to add the orion dc to dc

[CarlD]

Originally Posted by Dismantle

Wondering how I wire the trailer with a 7 pin? I don't want to cut the lights and other 7 pin features. Just want to add the orion dc to dc

I toasted one of the terminals on my dc to dc converter. It lasted for around 30k miles. I would sometimes draw 14 amps from the truck due to voltage drop. I believe it was because of poor connections at the 7 pin connector. I have since run a dedicated 10 wire AWG and connector from the truck to the converter. The current is now about 11 amps. If you are interested, I posted an analysis in this thread:
https://www.fiberglassrv.com/forums/...all-94581.html

[ThomasC]

Originally Posted by sokhapkin

Victron devices are good, but are extremely overpriced. Take a look at Renogy DC to DC chargers, they are much more affordable.

Renogy has a 50 amp and a 30 amp battery to battery in combination with it being an MPPT solar charger all in one unit. One nice thing that it does it will trickle charge your TV battery from solar if your house batteries are fully charged.

[John in Michigan]

Originally Posted by bigangelman

For these issues I check out Will Prowse YouTube videos. Or his Diyourself solar forums.

I check with Will Prowse as well regarding solar and batteries, etc. I found a DC to DC Charger thread on his DIY solar forum here:

https://diysolarforum.com/threads/dc...cussion.17211/

[John in Michigan]

DC to DC chargers can draw a LOT of amps. Even the Renogy 20 amp and the Victron 18 amp DC DC chargers could draw up to 30 amps from the tow vehicle. Even that is really beyond the capacity of the 7 pin connector 12 volt aux power/charging wire.

[sokhapkin]

Originally Posted by ThomasC

Renogy has a 50 amp and a 30 amp battery to battery in combination with it being an MPPT solar charger all in one unit. One nice thing that it does it will trickle charge your TV battery from solar if your house batteries are fully charged.

Wow, I did not see this in the Renogy manual... Trickle charging TV battery feature is nice!