Very beginner with all this, so please bear with me.
My main question is this: do the DC-DC converters use a little bit of power to change voltage, even before load is added to the system?
For context:
I recently connected a DC-DC converter (Orion 12/24-20) to my van’s battery. I am using it to boost the voltage from 12V to 30V so I can charge my Eco Flow Delta 2 better. I don’t have a switch installed, so I am just manually connecting the Eco Flow when I turn the vehicle on, and disconnecting it when I turn the vehicle off.
Recently the van has sat overnight at the mechanic for a few nights… and the battery has died. The Eco Flow was not connected, so I am lead to believe that the DC-DC converter itself draws a little bit of power to slowly discharge the car battery over time.
I just did some testing with a multimeter, and when I tested the cable that connects to the Eco Flow, it read 30V. I unplugged the little green connector for the remote on/off, and the voltage slowly dropped down to 12V. I interpret this to mean that the converter is still boosting the voltage, even while the Eco Flow is not connected. So is the converter using a little bit of power to do the conversion? That’s my only guess I can come up with for why the battery would be slowly discharging (the battery wasn’t dying overnight before the converter was installed). Any info would be greatly appreciated.
Standby current is listed in the datasheet/user manual for the device - there are a few versions, so I won’t link the specific one since I don’t know your specific version, but all user manuals and datasheets can be found directly at https://www.victronenergy.com/
Also worth noting that a DC-DC Converter is not a charger, and is not supported for use as one, so aberrant behavior may occur.
I assume “off load current” is the same thing as “standby current” that you mention. So < 30mA is pretty low. So would this be < 30mA per hour? And do you think that by unplugging (or connecting to a switch, like the datasheet suggests) the green connector for the remote on/off, it would stop pulling current?
The off load current (which I also read as standby consumption) can’t discharge a starter battery.
Measure current flow on the input and output of the converter, using a DC clamp meter, to figure out if the starter discharges through that route.
Other option is to use FLIR thermal camera to look at the whole system (while the starter battery has charge)… while energy can kind-of vanish into thin air, it’ll always heat up the location where it turns from electricity into some other form of energy.
Recently the van has sat overnight at the mechanic for a few nights… and the battery has died.
Occams Razor: The most likely reason is an open door keeping the lights on, draining the battery.
I have a similar problem. In a new Escape trailer I installed a LiIon battery and victron MPPT solar setup. When the WFCO factory, with battery auto detect, convertor is charging the battery and then shut down, the DC_DC (12 12-18) Draws about 2 amps. This verified by the Victron shunt and the battery BMS app. Overtime the DC-DC convertor gets warm. The app show the battery in bulk charge even after the breaker is opened for the shore power charger.
If I open the circuit between battery and DC-DC the current drops to the normal parasitic load. When I close that circuit the draw is in mAmps.
All this is on the Escape trailer wiring and with the tow vehicle disconnected.
This is on a 2 month old trailer. Could the DC-DC be defective?
True. 30mA of “off load current” would result in less than 1Ah of battery drain, which is nothing compared to 50Ah or more of 12V car battery.
Some thoughts of mine:
These Orion DC to DC are stated not isolated. So, being step-up converters, most pro they have the boost topology, where galvanically input to output is only a forward diode. So, if in and out are connected, even when not operating, the output voltage is input’s minus diode drop, e.g. for 12.8V battery the output is close to 12V-12.5V. So, even if not producing 18V or 30V (boost), the load might be drawing current from 12V (if connected). And I guess no “low batt disconnect” can protect the battery, if there is current flow through the diode. It has happened to me.
I do not know if this is the case (or an open door, a short etc), neither if Orions share this simple boost design, maybe Victron stuff could enlight us (since I do not own an Orion).
Input and output negatives are linked together and go to both the trailer plug and the chassis. This is ok. A bit of a waste to use an isolated Orion to then connect both negatives together, but works either way.
The input positive comes from the trailer plug, thats also correct.
But what i dont understand is the output positive. Why does that go back to the trailer plug, that voltage has no business going back to the plug.
Where exactly do you measure 2A? On the 8AWG red wire thats leaving the screenshot on the left side? If so, then i guess those 2A are going towards the trailer plug. If the schematic is correct, then they could power the brake lights if the breakaway switch is closed. Apparently theres breakaway switches that come with their own battery, so i guess it could be powering that, and as soon as the power is cut the breakaway system goes into standby?
The 10g wire going back to the 7 pin is for the emergency brake breakaway. The electric brakes need power in the event of breaking away from the tow vehicle. It was a convenient place to tap the positive battery 12v.
Both the victron shunt and the SOK battery app confirm about 2 amp draw. Also, over an hour or so the DC-DC is warm to the touch. I installed a 40 amp breaker between the DC-DC and the battery on the 8ga wire going to the battery. If I pop it open I see the current drop off.
