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Kevin Windrem avatar image
Kevin Windrem asked

Orion DC-DC Charger remote on plus engine shutdown

Is it possible to use remote on/off control AND engine shutdown logic?

I am using an Orion 18 amp isolated DC-DC charger between my tow vehicle and my travel trailer. I have almost a 2 volt drop in wiring between the TV battery and the Orion. I've done as much as reasonably possible to reduce this voltage drop so it is what it is.

I would like to add a control line from the TV to enable charging of the Orion but would also like to use the engine shutdown logic to control maximum charging current. This is not essential but desirable. I will fall back on remote control only if the two can't be combined. The manual says in order to use remote on/off, engine shutdown control must be disabled.

Anyone know for sure?


dc-dc charger
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kevgermany avatar image
kevgermany answered ·

Do it with the ignition switch. There will be a switched radio feed, piggy back on that.

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Kevin Windrem answered ·

To answer my own question: yes, you can combine remote control with engine shutdown logic. Just tried it and it works perfectly. The remote on/off shuts down the charger completely. When the remote is on, the engine shutdown logic functions as if there was no remote on/off control.

In my application, a switched ignition connection isn't possible as my trailer is connected by the traditional 7-pin connector, and there is too much voltage drop at full load of the Orion to detect that the engine is stopped when the Orion load is light.. I ended up using the running light connection to enable the Orion.

The combination of remote on/off and engine shutdown logic allows the Orion to manage maximum charge current based on its input voltage. It's not perfect because TV loads and engine RPM change the alternator voltage slightly.

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Kevin Windrem avatar image Kevin Windrem commented ·

I ran #8 wire from the battery to the 7-pin in the tow vehicle and #8 from the 7-pin to the DC-DC charger located at the back of the trailer. These wires in my 7-pin connections are #10. You might want to replace the 7-pin receptacle in the tow vehicle or the harness in the trailer if yours are #12 as you reported. In my trailer, the harness is 8' long and accounts for a significant portion of the voltage drop (2 8' #10s @ 20 amps is 0.3 volts, #12 is 0.5 volts). By comparison, the ~45 feet of #8 is another 0.6 volts.

I used frame connections for the negative path except through the 7-pin.

I am using a separate line to turn on the DC-DC charger rather than trying to use engine detection. I use the running light connection from a near by light to turn the inverter on. If you don't drive with lights on as I do, you'll need a separate line from the ingnition switch in the tow vehicle.

I was actually able to use the engine shutdown detection to control charging current should voltage drop below an acceptable level. The voltages I uses were V start: 3.8, V shutdown: 12.5, V cutoff: 10, V restart: 12.5. Yours will probably be different however you can see by the numbers that engine detection alone would not stop the DC-DC converter when the tow vehicle is turned off (about 13 volts after a full charge).

One other way to approach this would be to use a relay to turn off the +12 volt line to the 7-pin when the tow vehicle ignition switch is off. I realize "ignition switch" is more difficult with push-to-start common on newer vehicles but there should still be a signal wire somewhere.

A separate connection from battery to DC-DC converter, and using a separate connector at the back of the tow vehicle is probably best as it takes the load off the 7-pin's +12 and ground connections and provides a low resistance path. You could run #2 wire the entire distance. But still I don't think the engine detection could provide reliable shutdown.

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Bob K avatar image Bob K Kevin Windrem commented ·

I see how your Shutdown Detection Voltage is set to 10v. I think that's exactly what I need to do to force my 2017 Tacoma "high output" alternator to actually output high voltage and current. But of course, I need a way to completely turn off the DC charger so that the DC charger doesn't deplete the truck's starter battery down to 10v when the truck is turned off.

"I am using a separate line to turn on the DC-DC charger rather than trying to use engine detection."

How, precisely, did you wire the Remote On/Off connection to the DC charger? I presume it involves the LH jumper. Did you remove the black jumper wire from the jumper and wire your switched line (from nearby running light) to just the L or just the H terminal on the jumper? The manual is not as clear as I would prefer on how to configure the LH jumper for various uses.

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Bob K avatar image Bob K commented ·

I'd really like to hear the precise connection details you've used because I need to do the same thing with my 2017 Tacoma. The "smart" alternator runs as such low voltage (a known issue with the 3rd Gen Tacoma) that I struggle to get full charge with the DC charger. The best way I've figured to do this is to use the Engine Shutdown Detection function and to set the Engine Shutdown Voltage at about 12.4v. That way, the DC charger load pulls the alternator voltage down and signals the alternator to output more current (about 18 amps). Unfortunately, this also means that the DC charger continues to draw on the starter battery even after I turn off the truck until the truck battery is depleted to below 12.4v (approx 80% SOC) for 1 minute.


What I want to do is set the Engine Shutdown Voltage very low...say, around 11.5v. That way the DC charger puts a full load on the alternator and the ECM tells this goofy "smart" alternator to keep outputting high power. But I want the charging to end immediately as soon as I turn the truck off so that I don't deplete the starter battery to 11.5v.

I've read the instructions several times, but they're poorly written and seem to indicate that the Engine Shutdown Detection function overrides the Remote On/Off switch. What exact Remote On/Off connections did you make to (presumably) the LH jumper connections?

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Kevin Windrem avatar image Kevin Windrem Bob K commented ·

Leave the jumper on the Orion in place and connect the remote on/off to one of the two pins on the connector. This will allow the engine detection as well as the remote on/off logic to function. You need to insure there's a pull-down on the remote on/off line when you want the Orion to shut down. In my case the incandescent running/parking lights in the tow vehicle serve that purpose.

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