Ok I read the manual for your Orion and drew a basic diagram from your descriptions.
Your total DCDC input cable length is 40’ or 12.2m (there and back). With 6 AWG, volt drop shouldn’t exceed 0.5V at 30A (excluding connections, breakers and fuses) . You are seeing much more than this at only 1A to 2A current where volt drop should be around 20 to 30 mV. Cable length is not the root cause of the issues, quality of connections could be. The photo shows visible corrosion at the battery terminal.
For now, I dont like the 40A breaker on the charging cable at your start battery. Manual says 80A fuse recommended. If no volt drop across it when the system is running then leave it for now. Please don’t bypass it, even temporarily, as you then have no protection from a short and associated fire risk.
Input side earth cable from Orion to start battery : connection at common point on chassis for start battery earth is OK. Direct to battery negative = better. Direct to a clean dry truck chassis earth near the Orion = best. Check the earth point for corrosion under the bolt or lugs.
Please confirm earth cabling on both input and output side of the Orion conforms to Diagram 2 of the manual. The negative lead from starter/chassis must go into the negative terminal on input side of the Orion and not to the camper battery. The negative lead from camper battery must go to negative output terminal on the Orion. You can also earth the camper battery negative to the truck chassis if you want but since your Orion is the isolated version it is not necessary.
When you re-assemble everything and test run it, please use your multimeter to check actual voltages at the input and output terminals on the Orion and check if they agree with the voltages reported on your Smart Connect app. If there is still a problem this check will tell us if the issue is in the input cable, output cable or the Orion itself.
Hi James. I use an Orion XS which is similar in operation.
I have two solar charge systems. One keeps the House battery topped up and the other keeps the Chassis battery topped up.
The Orion passes surplus solar going to the Chassis battery over to the House battery and also operates whilst the engine is running.
I have my engine detection settings much lower because I wanted to avoid wasting solar in low sun conditions.
Most importantly the settings seem to work fine and are much lower than factory defaults.
In very simplistic terms.
If the start voltage is present, the DC - DC will start immediately as it determines the engine is running.
If delayed start voltage is present for the specified time and does not drop below it, it determines that the chassis battery must be charged and the alternator is available but not required to charge.
If the shut down voltage is reached it determines that the Chassis battery is being drained.
The worst that will happen is you will have difficulty starting your motor thus if have the ability to charge from shore without fear of being stranded you can tinker without fear.
I wouldn’t go any lower than 12.6v as that is the standing voltage for my chassis battery.
I have a hunch the Orion charger is bad, but here are all of the readings I took today with the truck running:
14.41V at starter battery
14.38V on both sides of 40A fuse at starter battery
14.37V at Anderson connector
14.37V at Cables (unplugged) that would go into input side of Orion charger.
12-12.8V (The readings fluctuate all over the place) at the input terminals of the Orion Charger. I have a feeling something is not well inside that charger.
Thanks for the diagram and the volt drop readings. The diagram shows a logical layout. Part of me wants to add a dedicated ground wire from the camper chassis to the vehicle chassis.
The volt drop readings upstream of the Andersen plug are all normal but it appears they were measured with no load/current.
When the camper is plugged in the Orion powers up and starts charging the house battery. Voltage at Orion input terminals fluctuates from 12 to12.8V.
The fluctuating readings at the Orion input make me think something is going in the cabling upstream but we are also seeing the Orion continuing to charge when it should have powered down and it reports charge states like “absorption” when it should be either “off” or “bulk”.
So I see two possibilities :
A cable issue between the Andersen plug at input to the camper and the Orion : Andersen plugs can develop issues over time. They rely on flat springs under the terminals to create a positive force that pushes the opposing terminals together when plugged in. Dirt, mechanical wear of the terminal faces, corrosion in the springs and cracks in the plastic casings can all weaken this joint. Give the Andersen plugs a careful inspection and also check the firmness of the crimp onto the cables. If this all checks out OK then ;
Orion has a fault
If you have a spare DCDC charger or can borrow one, try swapping them over. This will confirm one way or the other.
I want to make sure you saw I took a voltage reading at the wires immediately before the input side of the Orion. I agree there is no load, but just double-checking. I mention that only because it is after the Anderson connector (which I did inspect and recently re-crimp with a proper hydraulic crimper)
In my last several tests the Orion has been doing “some” things correctly. When I turn off the truck, it does report that the engine is off and stops sending power to the battery. However, I think we agree there is a problem that the unit continues to power the battery even when input voltage drops below the “Shutdown Voltage” when the truck is running. I also agree the unit shouldn’t be in Absorption charge at 68% SOC.
Would it make sense for me to unplug the lithium/house battery from the DC to DC charger and try again? Would that minimize the load? I also have a clamp meter that can checks amps, so I can take that reading along the whole path as well, but I’m not sure that would help.
Input voltage quite high due to cold alternator. It drops to around 13.9V after the engine warms up.
The XS is in “absorption” mode. This is due to the output voltage 14.2V being the absorption voltage setting. Since the current is below the absorption tail current threshold it will change to “storage” mode at 13.5V after a minute or two.
Your Orion TR Smart 12/12/30 has a slightly different settings menu. I’m not sure if has a “storage” mode. Probably “float” at similar voltage.
@JamesV I spent all day yesterday trying many different permutations, one of which was moving all of the camper components to the front of the vehicle and using new shorter wire to cable the starter to the orion. When voltage remained steady at 13.1V, I knew to carefully inspect the full cable run. You were right. Found it. Thanks you to @JamesV and for everyone else that stuck with me on this one. I REALLY appreciate the guidance and learned a lot about how this used (new to me) setup works.
