I’m stumped, can anyone help me solve this seemingly simple Victron DC to DC issue?

[imbuere]

This is what I would think would be a simple setup, but I can’t get it to work for some reason. Using these two components:

Battery: https://battlebornbatteries.com/product/12v-lifepo4-deep-cycle-battery/
DC to DC charger: https://www.amazon.com/Victron-Energy-Orion-Tr-110-Watt-Converter/dp/B07L6H8VKL

The victron output is connected to the battery with ~1 foot 12awg wires with properly sized and crimped connectors. Positive output to battery positive, negative output to battery negative. Victron is manually adjusted to be putting out 14.6v, confirmed with two different meters (And confirmed calibrated).

Ive tried hooking the Victron input to 3 different sources: 1) through a car cig lighter (1 ft ~16 awg wire, not ideal, I know) 2) a decent bench top power supply (1ft, 6awg) and 3) a different bench top power supply.

Using both bench top power supplies and the car cig lighter, I could never get the Victron to pull any more than 14.6 v, 0.07 amps (yes, seven hundredths). This 0.07 amp number was consistent between the output for both power supplies and confirmed with a clamp meter.

At first, I figured the Victron was a defective unit… but it’s replacement is exhibiting the exact same behavior.

other notes: I tried all recommended configs of the Victron switch, no change. If I hook the power supplies directly to the battery, I get the full 10amp draw (confirmed with clamp meter).

What the heck am I missing here??

 

[John Frum]

What is the voltage at the battery terminals without the charger attached?
What is the voltage at the battery terminals with the charger attached?

I wonder if your battery bms has disconnected.

 

[imbuere]

11.78 with the power supply attached and 11.78 with the power supply not attached. I think this is the same thing you're asking, but I didn’t detach the Victron (shouldn’t make a difference if it’s not powered, right)?

I don’t think it’s the battery because if I hook up the bench power supply directly to it, the battery pulls all 10 amps.

Unless…. The Victron is causing the Battery to disconnect (and the 0.07 amp draw is the Victron itself) and then it resets when I try the bench. Let me confirm (again) the Victron voltage output…

 

[John Frum]

11.78 with the power supply attached and 11.78 with the power supply not attached. I think this is the same thing you're asking, but I didn’t detach the Victron (shouldn’t make a difference if it’s not powered, right)?

Please disconnect the victron from the battery.

I don’t think it’s the battery because if I hook up the bench power supply directly to it, the battery pulls all 10 amps.

Sounds reasonable.

Unless…. The Victron is causing the Battery to disconnect (and the 0.07 amp draw is the Victron itself) and then it resets when I try the bench. Let me confirm (again) the Victron voltage output…

You could try putting a load across the victron output.
See if it will supply current to the load.

 

[imbuere]

Ok, an update: while fiddling around (disconnecting the Victron output to measure its v output) and then reconnecting, it suddenly is working.

GREAT, now I turn the power off and back on to test and we’re all of a sudden not working again.

3 observations:
1. with everything disconnected, the battery shows 12v (up from 11.78 as I left it charging a bit). At no point in the process does the battery not give me 12v… so I don’t think I have a battery disconnect issue. I also measures max voltage during the whole of one of these cycles and it never went near the battery bums disconnect voltage.
2. when everything is connected, but it’s not pulling or sending anything above 0.07 a, if I disconnect the Victron output and reconnect I can pull 8 amps. This is reliable until the power is cut and I have to dis and reconnect the Victron output again.
3. I connected the Victron output straight to my 12v fridge. With no battery in the picture, I don’t have to disconnect the Victron output each time the power cycles. At no point when the power supply is on is the fridge not on, even after multiple power cycles.

To me, #3 screams battery disconnect… but if it’s disconnected, then why am I reading 12v at the Battery with the power supply turned off? Unless there’s a separate charge and discharge cutoff.. but I wouldnt think that’s possible.

I’ve now gone from wondering what the heck I’m missing to what I don’t understand at all!

 

[chrisski]

9 amps is a lot to push through a cig lighter. Might need to direct connect to a battery.

11.78 or 12 volts seems quite low for a battle born battery .

 

[John Frum]

Single Port BMS MOSFETs Explained

Single Port BMS MOSFETs Explained

diysolarforum.com

 

[imbuere]

9 amps is a lot to push through a cig lighter. Might need to direct connect to a battery.

11.78 or 12 volts seems quite low for a battle born battery .

It’s a temporary solution, but I don’t disagree. It’s fused at 20a. This problem is repeatable with or without the cig lighter.

 

[imbuere]

Single Port BMS MOSFETs Explained

Single Port BMS MOSFETs Explained

diysolarforum.com

Ah, so if I’m reading this correctly, it is possible to have separate charge and discharge disconnects in the battery, right?

 

[John Frum]

Ah, so if I’m reading this correctly, it is possible to have separate charge and discharge disconnects in the battery, right?

Yes.

 

[mikefitz]

The battery BMS will have the ability to cut off either the charge or discharged path or both. Note even with the charge path disabled by the BMS you will still be able to measure a voltage . The voltage of around 12 volts suggests an almost discharged battery.

If you able to adjust the Orion output voltage, and it seems you can, try a load like a car bulb.

General points with the Orion. The link between the remote pins must be in circuit. The terminal clamp action needs care to ensure a correct termination.

What may be happening. The unit you have is a dc to dc converter, not a charger.
The dc to dc converter is protected against over current.
When connected to the lithium battery, due to the low input resistance, there is an high current flow, if this exceeds 32 amps or 12 amps for more than 10 seconds, the Orion will shut down.
Try turning the Orion volts down to just over battery volts and see what happens.

Mike

 

[imbuere]

The battery BMS will have the ability to cut off either the charge or discharged path or both. Note even with the charge path disabled by the BMS you will still be able to measure a voltage . The voltage of around 12 volts suggests an almost discharged battery.

If you able to adjust the Orion output voltage, and it seems you can, try a load like a car bulb.

General points with the Orion. The link between the remote pins must be in circuit. The terminal clamp action needs care to ensure a correct termination.

What may be happening. The unit you have is a dc to dc converter, not a charger.
The dc to dc converter is protected against over current.
When connected to the lithium battery, due to the low input resistance, there is an high current flow, if this exceeds 32 amps or 12 amps for more than 10 seconds, the Orion will shut down.
Try turning the Orion volts down to just over battery volts and see what happens.

Mike

I adjusted the Orion to just 0.02v above the battery. Same results. I also tried various (above and below battery/Orion’s setting) power supply voltages, same result.

If the battery is asking for too much current, wouldn’t I be getting the same results when it’s power cycled and when the output is reconnected? I would guess so.

if this dc to dc charger isn’t what I nee, is there any other economical way to solve this problem?

 

[Solar101]

Have you found a solution to your problem?
I am running into exactly the same problem with a Victron12V-12V 9 Amp DC-DC Converter. It will not charge the LiFePO4 battery in my RV when I started my van (connected to the battery through a 7-pin connector). I have to disconnect the battery, started my van, then it will work. But this is such a pain and not what I expected. Any ideas or suggestions?

 

[Tomthumb62]

started my van, then it will work.

That’s probably your answer.

If your starter battery is lead acid and aging, it may not have high enough voltage to provide to the DC-DC converter for a lithium battery. But when the van starts, now the alternator is providing 14.x volts or so.

Also your specific device a converter not a charger. I’m not entirely sure of the difference, but clearly they wouldn’t design and make a charger if the converter version did the same thing.