Constant Current Power Supplies Not Charging EcoFlow Delta

[CntrlAltDel]

Hi there,

I'm trying to charge my EcoFlow Delta with my EcoFlow River. I achieve this using a AC-DC PSU with an XT60i-F connector with the middle pin shorted to neutral. This should in theory place the EcoFlow Delta within solar charging spec to be able to do 12v+ and 8a+ charges.
Issue I'm having is that I've tried multiple ways of "clamping" the current from the DC PSU. If the current is not clamped then the EcoFlow Delta will try to pull more current than what the PSU can handle and cause the PSU to shutdown and charging to stop to avoid damage.

1. I've gotten a DC-DC Step Down Converter with current clamp (this works but obviously these things dont last very long operating at constant 250w load).
2. I've gotten a Mean Well XFG-200-24-A LED DC constant power PSU. This should have the above functionality to clamp down on current built it but still it seems it charges and then immediately stops which anecdotally I believe to be that the EcoFlow Delta is asking for more amperage than what can be delivered i.e 13a+ this shouldn't be a problem for a constant power PSU that clamps current but it is in my case.
3. I've gotten a Victron 24v 5a Blue Charger that has a power supply mode that also clamps current to either 2a or 5a. Both of those settings does the exact same thing as the mean well, it starts solar charging and then stops.

Does anyone know what could be the issue here?

 

[Vigo]

I guess my first question is, if all you need is 12v and 13+ amps, why not buy a <$30 power supply that far exceeds that? You can get a 20-30amp 12v power supply for $20 or so on Amazon.

 

[CntrlAltDel]

I guess my first question is, if all you need is 12v and 13+ amps, why not buy a <$30 power supply that far exceeds that? You can get a 20-30amp 12v power supply for $20 or so on Amazon.

I considered this option already but working with unknown variables here. I know for certain the voltage and amperage must be "clamped" or constant if I were to get a DC power supply with a clamped amperage of let's saying 30a I'm not sure if that would damaged the EcoFlow, my understanding up until now is that even if the DC power supply could deliver 100a and the maximum a device could consume was 10a, it should not pull more than 10a but I don't know if this behaviour would be consistent with a constant current power supply like the one I already mentioned.

I guess the question then is, if I were to for example get a DC PSU with constant current like the one above but for example it was above the amperage spec of the EcoFlow Delta Max i.e 20a where the max is 13a, would constant current overload and destroy the EcoFlow or would it behave just like any other DC electronic device only taking what it can support at maximum amperage?

 

[Vigo]

So 'constant current' itself may be misleading or misunderstood here. Most cheap power supplies like I was mentioning may have a current LIMIT (usually the cheapest ones do not and only have an adjustable voltage limit, not current). The actual amount of current that flows is determined by the voltage and resistance of the circuit. The power supply controls the voltage but not the resistance. The power supply will not 'chase' a certain desired amp setting by varying its own voltage, it will simply put an upper limit on voltage and then whatever current results from that is what you get.

So, just because you have a power supply capable of 50 or 100 amps or whatever, does not mean it will 'force' 100 amps through whatever you hook it to. It will simply provide a max voltage of whatever you set it to, and then whatever the resistance of the circuit you hook to it is, determines how many amps will flow. IF it has an adjustable current limit, it will vary its voltage DOWN to keep current under that limit, but it won't vary its voltage UP endlessly to try and guarantee you hit that current, it will just stop at whatever voltage limit you set it to.

So as long as the voltage you are hooking to the Ecoflow is acceptable for it, the Ecoflow itself is what will limit the current to a safe level.

 

[CntrlAltDel]

So 'constant current' itself may be misleading or misunderstood here. Most cheap power supplies like I was mentioning may have a current LIMIT (usually the cheapest ones do not and only have an adjustable voltage limit, not current). The actual amount of current that flows is determined by the voltage and resistance of the circuit. The power supply controls the voltage but not the resistance. The power supply will not 'chase' a certain desired amp setting by varying its own voltage, it will simply put an upper limit on voltage and then whatever current results from that is what you get.

So, just because you have a power supply capable of 50 or 100 amps or whatever, does not mean it will 'force' 100 amps through whatever you hook it to. It will simply provide a max voltage of whatever you set it to, and then whatever the resistance of the circuit you hook to it is, determines how many amps will flow. IF it has an adjustable current limit, it will vary its voltage DOWN to keep current under that limit, but it won't vary its voltage UP endlessly to try and guarantee you hit that current, it will just stop at whatever voltage limit you set it to.

So as long as the voltage you are hooking to the Ecoflow is acceptable for it, the Ecoflow itself is what will limit the current to a safe level.

Brilliant, that explanation clears up a misconception I had about how these constant current PSUs behave. One of the two I have is the:
Mean Well XFG-200-24-A
It has current control on it, the logic of buying this one was with the thought that it would not allow the EcoFlow to overdraw and cause the charge process to stop. The EcoFlow's solar charge specs are 11-100V DC up to 13A ( 800W max ).
I picked up a 1200w buck booster that has the same featureset that I guess would allow me to test what you are saying, I should receive it tomorrow.

 

[CntrlAltDel]

@Vigo I picked up a 12v 29a DC PSU. Seems now the behaviour is completely different. Seems now DC charging is now intermittent. I can confirm it's pulling about 15.45a @ 12.05v which is in spec for 'solar' charging. And the DC PSU itself, unlike the other 3 doesn't show overdraw warning light. I hear the *click* sound on the Delta Max when switching to solar charging mode then immediately after another *click* sound where the charging stops. That then repeats indefinitely.

 

[Vigo]

Are you watching the voltage while this cutting out is occurring? Based solely on what you've said and that video, I suspect you're dropping below a minimum voltage that the Delta Max will accept. Once the circuit 'opens' or releases, the voltage rises back above the threshold and charging begins once again. According to the Ecoflow website the Delta Max needs 11+ v on its input. Can you verify that voltage is not dropping into the 11s once the circuit loads up? Depending on where you are able to check that, you may have to consider that if the power supply itself is dropping into the 11s AND the wiring between the PSU and Delta Max is also dropping some voltage, it may be crossing into the 10.Xs inside the Delta Max.

Even if it doesn't, i would still try cranking up the voltage on the power supply a bit and see if it addresses the symptom. On the cheap PSUs ive bought from Amazon, the 12v 30a models could be cranked up close to 16-17v, while the 12v 50a models could not be cranked much beyond 12.00. Hopefully yours will allow you to adjust higher.

 

[CntrlAltDel]

Are you watching the voltage while this cutting out is occurring? Based solely on what you've said and that video, I suspect you're dropping below a minimum voltage that the Delta Max will accept. Once the circuit 'opens' or releases, the voltage rises back above the threshold and charging begins once again. According to the Ecoflow website the Delta Max needs 11+ v on its input. Can you verify that voltage is not dropping into the 11s once the circuit loads up? Depending on where you are able to check that, you may have to consider that if the power supply itself is dropping into the 11s AND the wiring between the PSU and Delta Max is also dropping some voltage, it may be crossing into the 10.Xs inside the Delta Max.

Even if it doesn't, i would still try cranking up the voltage on the power supply a bit and see if it addresses the symptom. On the cheap PSUs ive bought from Amazon, the 12v 30a models could be cranked up close to 16-17v, while the 12v 50a models could not be cranked much beyond 12.00. Hopefully yours will allow you to adjust higher.

I can confirm the output voltage is not dropping below 15.04v. I've added a DC-DC Step-up booster to keep the voltage at 15v from 14v (PSU max). It still behaves intermittently with no error code from the PSU.

I've just ordered an ammeter that's able to measure within 0-100v and 0-100a so I can adjust the current limiter on the step up booster. Just trying to explore all avenues.

 

[CntrlAltDel]

@Vigo I cannot believe it! So I just randomly had the thought that I should try to push the XT60i connector halfway into the port on the EcoFlow Delta. AND IT WORKS!
I immediately disconnected the 12v 29a DC PSU and tried the Mean Well XFG-200-24-A with the same premise AND IT WORKED!. This makes absolutely no sense.
Nonetheless thanks for all of your help.

 

[Brucey]

What do you mean half way? It's sitting half in the mppt port? How many amps is the Delta pulling?

Those ports are sometimes known to "fall in" to the unit.

 

[CntrlAltDel]

What do you mean half way? It's sitting half in the mppt port? How many amps is the Delta pulling?

Those ports are sometimes known to "fall in" to the unit.

Instead of pushing the XT60i 100% of the way into the port on the EcoFlow, I pushed it about 50% of the way in. Currently it's pulling 24v @ 8.3a.

 

[Brucey]

Ok so what's prob happened is the sense pin that will cause the Delta to think it's connected to solar isn't seating so then it defaults to its 8A car charging limit. I'd suggest using a normal xt60 connector cable in that case so you aren't risking an arc between the not fully plugged in connector.

 

[Vigo]

^ That's a good observation.

So is it correct that the only setup that charges correctly so far is the 24v psu? If the 24v works and none of the 12v solutions do it could be something to do with voltage inside the Delta dropping below 11.0 causing it to disconnect and then restart.

If it now works with the 12v 29a PSU and the 24v 8a PSU but not the Victron 24v 5a psu, it may be something like excessive ac ripple on the circuit causing it to freak out. I imagine that generally the closer you push an SMPS to its current limit, the greater the ripple on the output. But a possible ripple issue still feels like 'wild speculation' to me..

So far the only thing that makes sense is the observation about the sense pin. Either something is wrong with how that sense pin is wired on your charge cord, or it is kicking in some additional 'conditions' for the input power that aren't monitored when its plugged into a 'regular' xt60.

 

[CntrlAltDel]

^ That's a good observation.

So is it correct that the only setup that charges correctly so far is the 24v psu? If the 24v works and none of the 12v solutions do it could be something to do with voltage inside the Delta dropping below 11.0 causing it to disconnect and then restart.

If it now works with the 12v 29a PSU and the 24v 8a PSU but not the Victron 24v 5a psu, it may be something like excessive ac ripple on the circuit causing it to freak out. I imagine that generally the closer you push an SMPS to its current limit, the greater the ripple on the output. But a possible ripple issue still feels like 'wild speculation' to me..

So far the only thing that makes sense is the observation about the sense pin. Either something is wrong with how that sense pin is wired on your charge cord, or it is kicking in some additional 'conditions' for the input power that aren't monitored when its plugged into a 'regular' xt60.

All of the PSUs are working. I've made about 10 different XT60i cables with their own connectors. I just kept throwing them away thinking they were problematic. I tested @Brucey's theory also by putting a normal XT60 connector on the PSU and testing. It definitely limits the current as if the sense pin is not wired to the negative pole so this means that even with the XT60i connector half way in the sense pin is still working as intended. I think the conclusion here is the simplest one which is that the port on Delta is most likely imperfect I just wish it didn't have to cost me $350 of buying different equipment to figure that one out

@Brucey It definitely is not defaulting to car lighter power limits even in the video you can see a 200w input which is about double the limit of the car lighter limits.

 

[Vigo]

I think the conclusion here is the simplest one which is that the port on Delta is most likely imperfect I just wish it didn't have to cost me $350 of buying different equipment to figure that one out

Ugh! Well it's good that it's figured out but it sucks that it's sort of the most irritating possibility which is 'something that requires you to open up and repair the Delta' since it seems like the problem is in its actual xt60 port. Nice job figuring it out tho!