Victron Orion DC-DC charger not charging at full output?

[Dzl]

Which calculator or what math are you using to derive those values?
The calculator I am looking at is showing roughly half the Vdrop % you are showing (based on your numbers (I think) 13.4V, 20A, 25ft round trip)

 

[sduser]

I am using this one from calculator.net

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

Results match this one from wirebarn.com

Wire Size Calculator

Results are close but not exact to the one you are using, but you need to put in the total round trip distance (50')

 

[Dzl]

I am using this one from calculator.net

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

Results match this one from wirebarn.com

Wire Size Calculator

Results are close but not exact to the one you are using, but you need to put in the total round trip distance (50')

Ahh i see, I assumed 25ft was the round trip distance. Makes sense now.

 

[orangeminnie]

The 10.8V was from the battery sag condition drawing 18A with the engine not running. After the charger was shut off the battery immediately recovered to 12.5V. With the engine running I am at 13.4A at the engine battery and 12.8 at the charger input while pulling 18A.

Not sure that 0.2V (1.5%) is practical. Is that what the Victron wants? With a 13.4V source, 20A and 25 foot run, voltage calculator shows 12.8V with 8ga wire (5%), 13V with 6ga wire (3%) and 13.15V with 4ga wire (2%).

The "industry standard" is usually quoted as being <3% voltage drop. We like to design for <2% drop. It really does appear that you were popping in and out of low voltage disconnect, right? With less voltage drop in the wiring, that would be easier to manage. The input current is closer to 25A, with 18A output. I suggest using an on/off switch at the dash, to the Orion remote connector. It looks like you're operating OK now, so great!

 

[sduser]

The "industry standard" is usually quoted as being <3% voltage drop. We like to design for <2% drop. It really does appear that you were popping in and out of low voltage disconnect, right? With less voltage drop in the wiring, that would be easier to manage. The input current is closer to 25A, with 18A output. I suggest using an on/off switch at the dash, to the Orion remote connector. It looks like you're operating OK now, so great!

<2% is going to be tough, probably not going to happen. I may change to 6ga to get closer to 3% though.

I don't think it was going in and out of low voltage disconnect. I started the truck and watched the charge current on shunt for a while. It started up around 18A (250W) for a few minutes, then worked it's way down to 16.5V (220W) and stayed there for several more minutes. Then it started to drop again and was down to about 12A (160W) when I shut it off. The charger was slightly warm to the touch, but by no means hot. It was only running for 20 minutes or so.


I re-read the manual and noticed specific setup instructions. I'm not sure if I ever followed those instructions to the letter. I will do that and see if it makes a difference.

 

[orangeminnie]

Well now I think it's just overheating and folding back. Is the Orion in a tight area? It needs to breathe. As an experiment, put a temporary fast fan blowing on it. I have permanently mounted a 4" computer fan just above mine. It still will fold back on hot days, but never fails to work. My guess is that the lower the input voltage, the hotter it will run - another reason perhaps to have less voltage drop.

 

[mikefitz]

You don't indicate the state of charge of the battery. With a 13.7 volt charge setting and a battery in a high state of charge it won't accept full current and the current will gradually fall. This seemed to be what you are seeing.

Provided you set the voltages for input conditions you have, I suggest everything is working correctly. With a higher input voltage the conversion process is more efficient with less heat generated. There should not be a problem with the 18A unit but the 30A unit is a slight fail from Victron. It runs too hot and, as said, needs a fan to maintain full output.
The indicated voltage difference between the smart shunt and the charger may be due to a poor connection. Victron have had some problems with the inline fuse in the shunt sence wire, replace with a new 1 amp fuse.
I can't see from the pictures where this is connected, usually direct the on the battery positive. ( and the red cable on the negative confused me).

Mike

 

[sduser]

Well now I think it's just overheating and folding back. Is the Orion in a tight area? It needs to breathe. As an experiment, put a temporary fast fan blowing on it. I have permanently mounted a 4" computer fan just above mine. It still will fold back on hot days, but never fails to work. My guess is that the lower the input voltage, the hotter it will run - another reason perhaps to have less voltage drop.

Could be but it was only slightly warm when I was watching the output drop last night. I do have a small computer fan ready to install if needed. The charger is installed on a cargo drawer behind the seats. With the seat up it can get tight but it's not enclosed and does have airflow (see picture in first post).

 

[sduser]

You don't indicate the state of charge of the battery. With a 13.7 volt charge setting and a battery in a high state of charge it won't accept full current and the current will gradually fall. This seemed to be what you are seeing.

Provided you set the voltages for input conditions you have, I suggest everything is working correctly. With a higher input voltage the conversion process is more efficient with less heat generated. There should not be a problem with the 18A unit but the 30A unit is a slight fail from Victron. It runs too hot and, as said, needs a fan to maintain full output.
The indicated voltage difference between the smart shunt and the charger may be due to a poor connection. Victron have had some problems with the inline fuse in the shunt sence wire, replace with a new 1 amp fuse.
I can't see from the pictures where this is connected, usually direct the on the battery positive. ( and the red cable on the negative confused me).

Mike

In my initial post the battery was about 90%, but the charger was still in bulk phase so I would expect full current. Shortly after I discharged down to about 50% to see if that made a difference. Same issue.

So nothing special about the shunt + wire? In that case I will make a shorter one. The wire is all bundled up and not ideal. The shunt red wire is connected to the battery side of the class T fuse.

Sorry about using the red wire for negative. It's all I had at the time. Bad form I know. If I ever break down the battery I will replace with a black wire.

 

[GSXR1000]

The alternator should be outputting 13.5v to 14.4v i would trouble shoot that

 

[mikefitz]

nothing special about the shunt + wire? In that case I will make a shorter one.

No nothing special, the Victron problem was a volt drop across the inline fuse and holder, the fuse was creating a volt drop.

Mike

 

[LanduytG]

Get rid of the 8ga and go to 4ga. Also are you sure the battery is down enough to want more than 18 amps?

Greg

 

[sduser]

Get rid of the 8ga and go to 4ga. Also are you sure the battery is down enough to want more than 18 amps?

Greg

I am coming to that conclusion as well. At least 6ga, possibly 4ga. Just not sure yet how I am going to run it through the vehicle (full size SUV, not a RV).

I am assuming the battery would easily take the full 18A if available. It's only half full. Do you think the battery is limiting?

 

[mikefitz]

The Orion, to some extent, does not care what the input voltage is, provided it is above the cut in and drop out voltages. On tests I have run the Orion with a 12.0 volt input and a 14 volt set output. Providing it does not get too hot, the output current stays at the rated value into a test load. I don't think volt drops in the cable are your issue.
My previous comments suggested the battery is not accepting full current due to the low set charge voltage and the battery state of charge. To prove the point add some load to the battery whilst charging and test.

Mike

 

[Dzl]

<2% is going to be tough, probably not going to happen. I may change to 6ga to get closer to 3% though.

It may be cheaper, and marginally better to go with 2 x 8AWG if possible (2.3% vs 3%)
Or bite the bullet and go 4AWG

Just not sure yet how I am going to run it through the vehicle (full size SUV, not a RV).

I assumed (based on your 50ft round trip distance) this system was in like a Class A RV or 5th wheel or something. How did you manage a 50ft wire run in an SUV? Optimizing the wire run could help and be a lot cheaper than replacing the wire, if it is possible.

 

[sduser]

The alternator should be outputting 13.5v to 14.4v i would trouble shoot that

I tested this today. The alternator is a "temperature compensating" type. Initially voltage was 13.9V and dropped to 13.4V once the engine was nice and warm. I'll have to check the spec but I think that is normal.

 

[sduser]

The Orion, to some extent, does not care what the input voltage is, provided it is above the cut in and drop out voltages. On tests I have run the Orion with a 12.0 volt input and a 14 volt set output. Providing it does not get too hot, the output current stays at the rated value into a test load. I don't think volt drops in the cable are your issue.
My previous comments suggested the battery is not accepting full current due to the low set charge voltage and the battery state of charge. To prove the point add some load to the battery whilst charging and test.

Mike

I tested this today. I ran 6ga wire from the charger directly to the battery (fuse/shunt more specifically) and kept the 8ga wire from the battery to the fuse block / busbar. I put a current meter on the connection from the charger to the battery. When I turned on a 5A load, the current meter jumped by a couple amps for a couple seconds, then settled back down to what it was before. The shunt reading lowered by 5A.

So unless I am reading this wrong this does not seem to be the issue.

 

[sduser]

It may be cheaper, and marginally better to go with 2 x 8AWG if possible (2.3% vs 3%)
Or bite the bullet and go 4AWG

I assumed (based on your 50ft round trip distance) this system was in like a Class A RV or 5th wheel or something. How did you manage a 50ft wire run in an SUV? Optimizing the wire run could help and be a lot cheaper than replacing the wire, if it is possible.

Actual distance is about 18'-20' one way. I used 25' to be more conservative. If I were to take the most direct path, ignoring routing challenges, it would still be 16' or so.

 

[sduser]

I was going to temporarily connect larger wire and run a test to see if the output increased. But this guy did it for me

 

[PajSolar]

I was going to temporarily connect larger wire and run a test to see if the output increased. But this guy did it for me

well that was helpfull, i had similar issue but with a 30 amp charger which aparently pull 45 amps.....