EEVblog 1499 - EcoFlow Delta Pro 3.6kWh Portable Battery TEARDOWN!

[EEVblog]

Teardown of the EcoFlow Delta Pro 3.6kWh portable/home LiFePO4 battery solar inverter/generator.
Back in the old EEVblog garage!

US: https://us.ecoflow.com/products/delta-pro-portable-power-station
Australia: https://au.ecoflow.com/products/delta-pro-portable-power-station

[Omar Mekkawy]

Hi Dave,
Nice video as usual. I think that you forgot to upload the high resolution photos. Could you please upload them ?

I am trying to make a similar device using recycled laptop BMS:
https://github.com/omarKmekkawy/TIVAC_TM4C123G_SMBUS_BMS_INTERFACING

Thank you

[mairo]

Interesting choice in using XT60 connectors on the mains side. Wonder if they have the proper certifications for such use even on the inside of the unit. I have seen DC specs for it, not AC related?

It will be interesting to see a copy of all compliance tests for this unit -  conducted and radiated for all possible configurations such as AC/DC, DC/DC, AC/AC, relevant USB compliance, although  I am sure some local AU companies have already put it through theirs internal RF chambers to check if OK otherwise would not be for sale locally

A good follow up video would be how you can make a better (electric speck wise) and cheaper system form individual off the shelf components even if the outside look may not be as sleek and portable.

[EEVblog]

Hi Dave,
Nice video as usual. I think that you forgot to upload the high resolution photos. Could you please upload them ?

Done now, on my Flickr account.

[exup]

Ive been digging around Dave's YT channel to see if he has solar batteries installed. I assume you haven't gone down that path yet? Have you discussed reasons why on this blog.

Ive a 10kW system in Sydney but no battery as price versus payback was not worth it, but are we close to tipping point yet.

[EEVblog]

Ive been digging around Dave's YT channel to see if he has solar batteries installed. I assume you haven't gone down that path yet? Have you discussed reasons why on this blog.
Ive a 10kW system in Sydney but no battery as price versus payback was not worth it, but are we close to tipping point yet.

Price vs payback is not worth it for me. We don't have enough excess capacity. I'd do it for the fun and for videos though.
Very complicated arrangement I have, and some upcoming house renovations throw even more up into the air.
https://www.eevblog.com/forum/renewable-energy/solar-upgrade-again/

[Phoenix]

I've done a 10 minute reverse engineering of the inverter board.

[Phoenix]

Another one for the DCDC/MPPT board.

[tszaboo]

Those busbars, that are soldered down on the PCB, marked HS??. Anyone recognizing these, are they off the shelf parts or custom?

[thm_w]

Those busbars, that are soldered down on the PCB, marked HS??. Anyone recognizing these, are they off the shelf parts or custom?

Tons of cheap chinese BMS use these busbars/pads, but its hard to find an actual supplier.
Its not expensive to just get them custom made though, afaik.

https://www.aliexpress.com/item/2251832649836325.html
https://www.eevblog.com/forum/manufacture/searching-for-high-current-smd-bus-bar-component/
https://www.eevblog.com/forum/manufacture/smd-bus-bars/

[tszaboo]

Those busbars, that are soldered down on the PCB, marked HS??. Anyone recognizing these, are they off the shelf parts or custom?

Tons of cheap chinese BMS use these busbars/pads, but its hard to find an actual supplier.
Its not expensive to just get them custom made though, afaik.

https://www.aliexpress.com/item/2251832649836325.html
https://www.eevblog.com/forum/manufacture/searching-for-high-current-smd-bus-bar-component/
https://www.eevblog.com/forum/manufacture/smd-bus-bars/

I've had custom busbars ordered. I also had PCBs redesigned, because the tolerances of these parts were "how you doing". It's a niche part, that I have interest in due to my previous job. The hard part is getting them in tape and reel, so you can just give it to the assembler, and they don't charge you extra for manual steps.
So I spent a bit of time with google-fu, and came up with this:
https://bangteng.en.made-in-china.com/product-group/EqoTKPryYzht/nickel-tab-in-reel-SMD-Nickel-Tab-catalog-1.html
From this company, they seem to be nickel, or nickel plated steel. This would put it at 1/3 to 1/5 the conductivity of a copper busbar. On the other hand it's like 1-2 cent a piece. For a large board, it makes a lot of sense, since the alternative is stepping up the number of layers or the layer thickness, that would probably cost more than buying 50 of these.

[EEVblog]

The EcoFlow AC output just mysteriously switched off when powering my 3 fridges 
And I suspect that the AC output actually briefly hiccups when the AC input comes on and off to charge. Will bring a scope home tomorrow to check.

Anyway, it's giving me the heebie jeebies. Might not go ahead with my transfer switch installation, might wait for the hybrid inverter and fixed battery solution.

[mikeselectricstuff]

The EcoFlow AC output just mysteriously switched off when powering my 3 fridges 
And I suspect that the AC output actually briefly hiccups when the AC input comes on and off to charge. Will bring a scope home tomorrow to check.

Anyway, it's giving me the heebie jeebies. Might not go ahead with my transfer switch installation, might wait for the hybrid inverter and fixed battery solution.

Maybe it can't handle the startup surge, especially if more than one of them decides to start at the same time

[tszaboo]

The EcoFlow AC output just mysteriously switched off when powering my 3 fridges 
And I suspect that the AC output actually briefly hiccups when the AC input comes on and off to charge. Will bring a scope home tomorrow to check.

Anyway, it's giving me the heebie jeebies. Might not go ahead with my transfer switch installation, might wait for the hybrid inverter and fixed battery solution.

Maybe it can't handle the startup surge, especially if more than one of them decides to start at the same time

I had fridges, that gave such a large kick to the network, when it's compressor switched off, that a coffee maker was making popping noises. They can be really really EMC noise sources.
The other issue  I can imagine is with the imaginary currents of the motors.

[thexeno]

Hi,

anyone has info on the batteries? I am working on LFPs, and I saw a Chinese brand with prismatic LFP cells of similar size, actually these ones https://batteryfinds.com/product/eve-90ah-lifepo4-battery-cells/

Would be fun if they use these ones, as I had a few in my lab now for some experiments. And the quality is quite... debatable.

[thm_w]

Hi,

anyone has info on the batteries? I am working on LFPs, and I saw a Chinese brand with prismatic LFP cells of similar size, actually these ones https://batteryfinds.com/product/eve-90ah-lifepo4-battery-cells/

Would be fun if they use these ones, as I had a few in my lab now for some experiments. And the quality is quite... debatable.

You can watch Will Prowse, he seems to review many of these. https://www.youtube.com/c/WillProwse
What quality issues specifically?

[EEVblog]

The EcoFlow AC output just mysteriously switched off when powering my 3 fridges 
And I suspect that the AC output actually briefly hiccups when the AC input comes on and off to charge. Will bring a scope home tomorrow to check.

Anyway, it's giving me the heebie jeebies. Might not go ahead with my transfer switch installation, might wait for the hybrid inverter and fixed battery solution.

Maybe it can't handle the startup surge, especially if more than one of them decides to start at the same time

Yeah, maybe, but it's got 3600W pulse capability. In any case, not reassuring for long term use.

[mikeselectricstuff]

The EcoFlow AC output just mysteriously switched off when powering my 3 fridges 
And I suspect that the AC output actually briefly hiccups when the AC input comes on and off to charge. Will bring a scope home tomorrow to check.

Anyway, it's giving me the heebie jeebies. Might not go ahead with my transfer switch installation, might wait for the hybrid inverter and fixed battery solution.

Maybe it can't handle the startup surge, especially if more than one of them decides to start at the same time

Yeah, maybe, but it's got 3600W pulse capability. In any case, not reassuring for long term use.

Dp they define the pulse characteristic? A compressor starting up against refrigerant back pressure would probably draw power for rather longer than, say, SMPSU inrush

[negative_feedback]

Interesting, no EcoFlow comission link in video description... I like that.

I have some questions:
1) Can someone confirm X-Boost* cheating by using lower voltage
2) Which is better, LFP or NMC in terms of AC Wh capacity?
3) They just released Delta 2 with LFP, what about River 2?

*can be disabled

[EEVblog]

Dp they define the pulse characteristic? A compressor starting up against refrigerant back pressure would probably draw power for rather longer than, say, SMPSU inrush

AFAIK there is no pulse or duration to spec to that.

[thexeno]

What quality issues specifically?

"Air" in their electrolyte. Eloquent is the bubbling sound when rotating the cells. And consequent risk of partially drying out over time.

[electr_peter]

2) Which is better, LFP or NMC in terms of AC Wh capacity?

Currently NMC are cheaper for the same capacity, but difference is not much. I would go with LFP for longer usable life and less potential fire risk.

3) They just released Delta 2 with LFP, what about River 2?

EcoFlow released many new products, they could have plans for smaller models as well. Other manufacturers have LFP variants in smaller size already.

[electr_peter]

I think measurement of the fridge startup power is in order, as it could be much higher than expected. Dave may have equipment to measure inrush current (power analyzer like R&S® HMC8015). IMO problem arises from different interpretation of power (i.e. domestic average power (with massive peak loads from mains) for fridge vs strictly defined portable inverter power output). Mains power is much more forgiving than inverter.

As OP suggested, fridges do not like power interruption and immediate startup. This can be mitigated with some relay delay logic (standard components for electric panel) by setting A) different time delays for all 3 fridges (so that startup load does not overlap) and B) long enough delays to reduce resistance from fridge internals. Losing power for few minutes in fridge is not a problem.
These mitigations could be enough for portable battery solution. If that does not help, soft-start circuit can be added for each fridge. Depends on load characteristics and inverter capabilities.

[Billy Tree]

 EEVblog Just like to clear up a couple things. The AC does not hiccup like that in a healthy unit. Usually such issues on the Facebook Ecoflow Delta user page prove to be user error.
The App has a number of timeout settings, and it is most likely your Delta Pro AC simply timed out. Also when it is plugged into the wall, the DP is passing through the AC input, the AC output simply reflects the AC input, it is not and cannot run off the battery plugged into the wall. This is for two reasons, one is a routing relay is flipped, and the other is the DC to AC inverter board is reversed to become an AC to DC fast charger. This is the secret sauce behind all the Ecoflow product's X-Charge extremely fast charging. It will even charge at 240V AC on the AC input even in the US models, however it will protectively mute the 120V output. Also plugged in the wall it is limited to a 20A AC passthrough, if you demand more it triggers an overcurrent warning. If your fridges sum to more than 20A, this may have been your issue.
The 3600 watts the Delta Pro is rated at are not surge/peak watts, it has 7200 "peak" watts. The 3600 watts are 120V x 30A running watts. And it will multi charge at up to 6500 Watts.
It's a beast. If your 3 fridges are typical theyare a trivial load for the Delta Pro really.
As for someone's certification questioning re: the XT60 DC input, the Delta Pro has UL, CE, FCC, RoHS, TELEC certifications.
HTH.
- Billy

[EEVblog]

EEVblog Just like to clear up a couple things. The AC does not hiccup like that in a healthy unit.

It does, there is even a warning about it in the manual.

[EEVblog]

I just realised that it's possible to overcome the main input switching problem by using a mains powered DC supply into the solar input. I have quite a few PSU's lying around...

[Billy Tree]

EEVblog Just like to clear up a couple things. The AC does not hiccup like that in a healthy unit.

It does, there is even a warning about it in the manual.

Where exactly does it say that in my Delta Pro manual?
I am quite active on the facebook Delta user group and an early adopter of the whole line, with two original Delta 1300's, a Delta Pro, and a new Delta 2.
It is NOT normal for any Ecoflow Delta to "hiccup" when outputting AC power - at all. None of mine do that.
Were you plugged in the wall when you were powering your fridges?
There are limitations on how much current the DP can pass through - but that's a operator issue to observe the device's parameters.
If the AC power was cut and the DP switched from the AC input to battery power, there is a 30ms switchover time. That is also a device parameter. My cable modems, routers and TV's do not even blink when that has happened, certainly my fridges, the portable and my Haier Quad have had no issues.

[EEVblog]

EEVblog Just like to clear up a couple things. The AC does not hiccup like that in a healthy unit.

It does, there is even a warning about it in the manual.

Where exactly does it say that in my Delta Pro manual?

3.10 Emergency Power Supply (EPS)
The product supports EPS. When you connect the grid power to the AC Input Port of the product
through an AC cable, you can power electrical devices through the AC Output Port (AC power will
come from the grid and not the power station in this situation). In case of a sudden blackout, the
product can automatically switch to the battery powered supply mode within 30ms. As a basic UPS
function, this function does not support 0ms switching. Please do not connect the product to any
device that requires 0ms UPS, such as data servers and workstations. Please test and confirm the
compatibility before using the product. We recommend that you only charge one device at a time
and avoid using multiple ones at the same time to avoid overload protection. EcoFlow takes no
responsibilities for any device failures or data losses caused by failures to follow instructions.

[/quote]If the AC power was cut and the DP switched from the AC input to battery power, there is a 30ms switchover time. That is also a device parameter. My cable modems, routers and TV's do not even blink when that has happened, certainly my fridges, the portable and my Haier Quad have had no issues.[/quote]

Yes, it's that 30ms. This is an issue for one or more of my fridges causes, I can physiucally hear the violent compressor restart. I'm not going to do this twice a day every day.

[electr_peter]

Other EcoFlow models also has ~30ms interruption in UPS mode (withing from mains power to inverter). It is mentioned in EcoFlow video EcoFlow Lab: Unveil R600 Smart Inverter [time stamp 06:36]

[Billy Tree]

Other EcoFlow models also has ~30ms interruption in UPS mode (withing from mains power to inverter). It is mentioned in EcoFlow video EcoFlow Lab: Unveil R600 Smart Inverter [time stamp 06:36]

It is disingenuous to characterize Ecoflow's 30ms switchover time between AC pass through mode and running off battery power as "a hiccup in AC power."
They are hardly unique in this - give me a list of other manufacturer's units that do this faster.
And you can avoid the switchover issue entirely, by powering the DP from DC power.
The dual direction inverter - charging board is what made Ecoflow the state of the art in So Gens all the other have been chasing.
That made an hour to 80% possible, previous legacy companies like Goal Zero and Jackery took 10 hours or more to recharge their So Gens.
That reversal and the relay switching takes time - but nevertheless
My Haier quad and my tenant's fridge certainly have never suddenly jumped into a "violent compressor restart" during the 30 ms switch over.
Even running off of Ecoflow's modest 600W output River Max unit, let alone an 1800W output Delta.
Really EEVblog's complaint - and configuration of 3 fridges is fairly unique, what kind are they exactly? Are they industrial/commercial units?
We can look at the specs.

[EEVblog]

Other EcoFlow models also has ~30ms interruption in UPS mode (withing from mains power to inverter). It is mentioned in EcoFlow video EcoFlow Lab: Unveil R600 Smart Inverter [time stamp 06:36]

It is disingenuous to characterize Ecoflow's 30ms switchover time between AC pass through mode and running off battery power as "a hiccup in AC power."

It literally is a hiccup, you can see it on a scope and I showed it in the video. Pointing out an aspect of a product that might cause problem (did so in my case) is not "disingenuous".

My Haier quad and my tenant's fridge certainly have never suddenly jumped into a "violent compressor restart" during the 30 ms switch over.

Good for you. Mine did.

Even running off of Ecoflow's modest 600W output River Max unit, let alone an 1800W output Delta.
Really EEVblog's complaint - and configuration of 3 fridges is fairly unique, what kind are they exactly? Are they industrial/commercial units?
We can look at the specs.

Does it matter? It caused a problem, end of story.
I'll use the DC input as I said.

I don't know why you have such a bee in your bonnet about this?

[Monkeh]

I don't know why you have such a bee in your bonnet about this?

You're daring to criticise his favourite product and he fancies an argument. Perhaps he gets paid to go review these things and feels he needs to defend them too..

[Ed.Kloonk]

I know you don't want to, but having looked at it, how hard would it be to manipulate the oscillator freq?

With old plain-jane inverters, I've wondered the viability of adding a circuit that 'leans' on the oscillator to sync it up with the mains, then switch over on the zero cross. (or 30ms before perhaps?)

Again, not asking can you. Asking could you? (with a modern model like this)

[EEVblog]

I know you don't want to, but having looked at it, how hard would it be to manipulate the oscillator freq?

With old plain-jane inverters, I've wondered the viability of adding a circuit that 'leans' on the oscillator to sync it up with the mains, then switch over on the zero cross. (or 30ms before perhaps?)

Again, not asking can you. Asking could you? (with a modern model like this)

Probably possible, but you totally wouldn't bother. The bigger dead period gap might cause you to come-a-gutsa anyway, so you are better off just getting a proper zero switch time UPS.

[Ed.Kloonk]

I know you don't want to, but having looked at it, how hard would it be to manipulate the oscillator freq?

With old plain-jane inverters, I've wondered the viability of adding a circuit that 'leans' on the oscillator to sync it up with the mains, then switch over on the zero cross. (or 30ms before perhaps?)

Again, not asking can you. Asking could you? (with a modern model like this)

Probably possible, but you totally wouldn't bother. The bigger dead period gap might cause you to come-a-gutsa anyway, so you are better off just getting a proper zero switch time UPS.

I wonder if the two freqs were indeed 180 degrees out of phase and that's why the fridge had a fit. Or a better question might be does the fridge still freak out with a 30ms interruption of steady power? 30ms seems too long anyway. Consumer ups are ~9ms aren't they?

Still be interested to know how the output frequency is derived. A discrete oscillator or from the micro.

The concern I have with the high impedance of the inverter, does one fridge starting muck up the other one running on the same line?

I wanna see some sacrificial fridges in the name of science (prior to entering summer lol).

[mikeselectricstuff]

As a comparison. the Bluetti AC500 switches to inverter in one half-cycle ( 10mS), and back with no obvious glitch at all - it re-syncs to the mains before switching back
https://youtu.be/RuEO17uvI8M?t=1954

[Billy Tree]

My objection is characterizing a specification stated up front as some kind of design flaw.
And your 3 refrigerators is not a typical use case, neither is your issue for any other user on the groups - and there have certainly been complaints.
Are they commercial refrigerators or just typical capacity household units?

[EEVblog]

My objection is characterizing a specification stated up front as some kind of design flaw.

It literally is a design flaw 
Which is why it's mentioned in the manual, so people are aware of the flaw, but I didn't see that before I did the video, which is why titles the video "RTFM Dummy"
You are just being pedantically annoying now.

And your 3 refrigerators is not a typical use case, neither is your issue for any other user on the groups - and there have certainly been complaints.
Are they commercial refrigerators or just typical capacity household units?

Just normal household fridges.
It's not the three fridges that is the issue, it's at least one of them that is disturbed by the brief interruption, but not always, it depends on what cycle it's on I suspect.
I will not discuss this further with you.

[EEVblog]

FYI, someone in the Youtube comments pointed me to fridge brownout protectors.
https://www.amazon.com/Exceline-Voltage-Electronic-Protector-Refrigerators/dp/B07Z5BH691
Silicon chip even did a project:
https://www.altronics.com.au/p/k6049-240v-mains-brownout-protector-kit/
And they don't seem to be a thing in Australia? I can't find one with an Australian plug

They detect the brownout and add a several minute delay for the fridges to lose pressure before connecting the mains.

I'm not aware of a DIN rail mount version though? A simple DIN timer may not dectect the brownout.
EDIT: Found one: https://d347awuzx0kdse.cloudfront.net/nawcontrols/product-download/17udt0.pdf

[electr_peter]

So theory that fridges are very fussy about brown-outs is confirmed. Probably because compressor has to overcome internal pressure "step", otherwise it stalls and loses momentum (and can't start again properly).

DC-DC converters, MCUs, FPGAs also may go crazy during brown-outs (via different mechanism, of course).

I see future video about this topic