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dgravlin avatar image
dgravlin asked

DC to DC Isolated Charger 12-30 Shows output voltage but no current flow.

I have a lithium battery, Victrom BMV and Victron Isolated DC to DC charger (12-30) on our truck camper. When the engine is running, the Victron App for the charger shows an input voltage that will trigger the charger to kick on. The output voltage from the charger reads 13.5-14v. I've confirmed these values with the Victron App and a multimeter. But there is no current flowing to the battery (which is not fully charged). The Victron BMV shows no current flowing into the battery, and I've confirmed that with a multimeter. So do I have a faulty DC to DC charger or am I missing something in the set up. The distributor (Dragonfly Energy in Reno) has been no help - they have not been answering their phones or returning voicemail messages. Any help appreciated. img-3057.png

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orion-tr smartorion dc-dc
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5 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Check the wiring between the Orion and your battery. Is there a switch (open) or a fuse (blown)?

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solar-taco avatar image
solar-taco answered ·

I am having the same problem with 12 | 12 - 18.

I have tried everything besides opening it up and taking it apart. The device seems to be broken.

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kevgermany avatar image kevgermany ♦♦ commented ·
You might want to try disconnecting the battery and see what output voltage it gives. Then try a 12V bulb across the output terminals.

If this is successful, please post your charger settings.

Otherwise it's a dealer job.


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604dave avatar image
604dave answered ·

This is not an answer but a continuation of the original poster's issue.

My set up is similar and I am also not seeing the current from the DC converter (Victron Orion 12/12-9) register on the BMV (Victron Smart 712). The answers above didn't answer the main question: should the current from the DC converter register on the BMV reading? It seems to me it should.

My Dealer has been good at getting back to me but his latest answer is simply that the BMC will not register the current, the reason is unclear to me:

"This isn’t a warranty thing. Since this is a DC-DC Converter it will not put any voltage out higher than the 12.x volts that it puts out. It’s meant to be a power supply not a charger. It can work as it will be feeding the batteries 12v when it is operating. You will not see an amperage reading on the BMV or Cerbo.

Yeah it most likely wont show up on the BMV but it will be putting charge into the batteries regardless up to the 12.x volts that it can make. So it will float the battery more than charge. A charger would take the voltage right up to 14v or 15v to get the battery up to a a resting voltage of 13.3v"

I'm posting a video of the set up and my voltage readings. What is not shown is that on the BMV app - I have never seen current register even driving on the highway.

Any help is appreciated, I'm stumped!


IMG_5426.MOV


img-5426.mov (93.4 MiB)
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drparker151 avatar image
drparker151 answered ·

Well you've kind answered your own question, If you turn off the DC-DC power supply how much of a draw from every other DC load is put on the batteries? The DC-DC power supply will be feeding them instead of your batteries being drained. If the batteries are at or above voltage supplied by power supply if cannot take them higher thus no flow across the shunt. You need a DC-DC charger to hit bulk charge voltages.


EDIT to ADD. If you want to measure flow from the DC-DC power supply add another shunt directly to it.

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604dave avatar image 604dave commented ·
Thanks DR for your response.


I can add these observations:

  • no loads on the aux. batteries
  • disconnected solar source
  • aux. batteries at approx. 50% capacity
  • still zero current registered on the BMV
  • engine running at 2500 RPM


In your answer above, shouldn't the DC DC current be registering on the BMV?


Kevin (below) seems to agree with me that since the DC converter is connected to the load side (not battery side) that I should be getting readings on the BMV.

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Kevin Windrem avatar image Kevin Windrem 604dave commented ·
Yes, you should be seeing charging current from the DC-DC

If you have a DC camp-on current meter or can break the connection and insert one in the path and do not see any charging current then something is wrong with the DC-DC charger.

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604dave avatar image 604dave Kevin Windrem commented ·
OK thanks for that confirmation Kevin. I'll try what you've suggested.


Much appreciated!


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Kevin Windrem avatar image Kevin Windrem 604dave commented ·

Measure the voltage at the output terminals and compare that to the voltage reported in VictronConnect. If there is a substantial difference, you may have a loose connection.

Another thing you can try is to disconnect the Orion output and connect a resistor (or incandescent automotive light bulb) across its output. See if it supplies current in this test or if the output voltage drops. A 10 ohm resistor is about 20 watts at 14.4 volts.

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604dave avatar image 604dave Kevin Windrem commented ·
  1. I disconnected the load (and BMV) from the DC converter. With the engine idling the input is about 14.2V and the output is 15V (I adjusted the voltage screw to produce max voltage). So it is boosting the voltage.
  2. When I connect the load again (with BMV in line and engine still idling) the voltage does not show up on the BMV - except for a few odd blips jumping from 12.47V to 12.48V - like a trace of voltage in a very erratic pattern, then disappears again and does not reappear after 5 more minutes idling. (see screenshot)
  3. Current remains zero (see screenshot)
  4. The Victron unit made a high pitch hum for a few seconds - but now I don't hear it.img-5453.jpeg
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Kevin Windrem avatar image Kevin Windrem 604dave commented ·
With the converter output set to 15 volts you may be triggering over voltage protection in your battery's BMS or overloading the DC-DC converter output.

You need to bench test the unit with a light bulb, etc as a load and see what is going on.

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Kevin Windrem avatar image Kevin Windrem 604dave commented ·

Also, you are using a CONVERTER instead of a CHARGER which will result in unpredicted results.

If the output voltage is set high enough to reach absorption voltage, it will not drop to float voltage when the battery is fully charged. This can damage the battery.

If the output voltage is set to float voltage the battery will never be fully charged. This can result in damage to a lead acid battery or result in unbalanced cells for a lithium. Neither of which is good for the battery.

The converter could be entering an overcurrent condition and Victron does not say if this will result in a current limited output or simply a shutdown of the converter.

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Kevin Windrem avatar image
Kevin Windrem answered ·

If you have connected the DC-DC charger output to the battery side of the BMV shunt, the shunt will NOT see the charger's current. ALL connections beside the battery bank should be connected to the Load/System side of the shunt. This includes all charging sources like the DC-DC charger.

You need to do this so the BMV counts the charging current and updates the SOC.

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604dave avatar image 604dave commented ·

Thanks Kevin,


Yes, I do have the DC-DC charger connected on the load side of the system.

So, shouldn't the BMV be registering the DC-DC converter current?

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kevgermany avatar image kevgermany ♦♦ 604dave commented ·
Yes
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cdgatti avatar image cdgatti 604dave commented ·
Did you ever solve?
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