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Delta PRO Firmware Review

Please read the deep dive review article about the DeltaPRO if you haven’t done yet HERE.

Want to know how the Delta PRO performed after more than 6 months of continuous use? Read the detailed article HERE.

Firmware .85 was released on the 14th of May 2022 with the following fixes:

  • Support power station grounding adapter.
  • Fix for the remote control to stay on more than 1 minute when connected via network cable to the DP.

This time the update showed inside the DeltaPRO settings and wasn’t as chaotic as previous one but I had to launch the update twice as the first time it ended abruptly at the 82% mark and the DeltaPRO didn’t feel right so I waited patiently until the update dot showed up again and this time it told me to update from to… I did that and thankfully this time it completed correctly. The whole process took around 23 minutes. I hope Ecoflow continue to polish the update process to a point where you don’t have to babysit and wonder if everything went well.

As with the previous update, thanks to my “DeltaPRO Data Insight” program, I was able to check that once the new firmware is correctly uploaded and flashed, the DeltaPRO resets it’s (estimated) capacity to exactly 3648W.

This time around I can confirm that the DeltaPRO remote control is finally behaving as it should have but with a caveat; The remote will MIRROR exactly the DeltaPRO in everything so if the DeltaPRO LCD is on, the remote LCD is on, if the DeltaPRO LCD is off the remote LCD will turn off. There’s no way to have the DeltaPRO LCD off and keep the remote LCD on (quick press the power button on the DeltaPRO, LCD turns off then go to the remote and press the remote on/off small button; the remote will turn on for a second and then turn off). I was hoping to keep the DeltaPRO LCD off while the remote is always on but… I’ll take what I can get and call it a day.

I don’t have the means to test the other fix mentioned in this update so hopefully someone else will.

Keep an eye here as I continue to update the article with my findings as soon as I’m finished testing as some tests take many hours to complete.

Current testing checklist:

  • The below 40W bug is not fixed; when the input goes below 40W it won’t get reported by the DP even if it is still being used.
  • The MPPT controller still has the same issues as before so nothing has changed.
  • When reaching 100% charge via MPPT, the cell-balance is still out of whack compared to < .74 FW and the constant charge-discharge cycle bug of the MPPT/SOC controllers doesn’t help at all.
  • As with previous version, the DeltaPRO will no longer charge to full capacity. It will loose around 5% of usable capacity and as mentioned above, once it reaches 100% it will enter an endless charge-discharge cycle. With FW < .74 the DeltaPRO would reach 3.684W/52.80V which is it’s full declared capacity. I know that for a fact because when you update the FW, the SOC resets all values and by default it will show 3.648W of total capacity (via my own program that exposes all the internal data of the DP).
  • Another issue I’ve noticed is that when charging from MPPT, if you’re close to 100% full charge, the algorithms don’t reduce the charge rate at all so you will jump instantly from 95% to 99% as now the cutoff voltage is reduced to 52V from 52.80V. The logical thing to do is to reduce the rate of charge as you approximate 100% by lowering it until you reach the “trickle charge”.
  • The DeltaPRO SoC capacity algorithms are still the same bad ones as with .74 and a lot worse than < 74 FW.
  • If you try the trick to make the MPPT controller disengage and stop charging the DeltaPRO once it reaches 100% (to try and stop the constant charge-discharge-charge bug) via app by setting a “charge level” to 95% and once the DeltaPRO is below 100%, change back the “charge level” setting to 100%, the mppt controller will not charge or will take a very long time to engage and start charging again.
  • The MPPT controller has another issue where it will freak out and underperform by as much as 50%; Stable production at around 80V and 600W before freak-out, then all of a sudden the controller will reset and lock itself < 40V with very high Amps, so high that the arrays can’t deliver and watts dip below 300W. Only way to fix this is to disconnect the solar arrays, wait 30 seconds, reconnect and pray that the mppt controller will latch on again with proper values. If not then rinse and repeat until it works…. šŸ™

All in all, the only real fix (of sorts) is the DeltaPRO remote that now stays on as expected.

My biggest grief is with the appalling state of the MPPT controller with it’s multiple bugs and problems… it is BROKEN and SERIOUSLY NEEDS some love from Ecoflow engineers to make it work as intended in a system that is relied upon 24/7.

(I’ve been fighting for the last 15 minutes to make the MPPT controller engage and actually use the power of the sun instead of draining the battery but it won’t budge… extremely frustrating to put it mildly…)

I hope Ecoflow will keep pumping out better firmwares and improve all of the DeltaPRO issues and as always I’ve offered my help countless times.

14/06/2022: DO NOT UPDATE TO .85 and if you have already updated to .85 then DO NOT RUN YOUR DeltaPRO in EPS/UPS/PASSTHROUGH mode or you risk seeing “error 121” and then killing your DeltaPRO. Me?… oh well, like countless others I’m patiently waiting for my replacement DeltaPRO…

17/06/2022: It’s been 8 days since the DeltaPRO blew up and my replacement is STILL in Germany at the shipping company! The EARLIEST I can hope for is next Tuesday so a total of almost TWO WEEKS DOWNTIME!!!!!!!! The shipping company is HELLMANN and it is now the WORST I have dealt with.
Funny thing is that UPS picked up my broken DeltaPRO and in less than 24 hours it is already in Frankfurt/Germany! Why send the broken DeltaPRO with such premium fast shipper and the replacement one with worst/cheapest/slowest shipper ever!?
Have I made a big mistake?! My faith in Ecoflow is in freefall…

19 thoughts on “Delta PRO Firmware Review

  • I udpated my two Delta Pros to “85” firmware yet when I check the version number it still shows 74. ????
    I’ve noted that (UK version) the mains sockets show Live to Neutral 230V as expected. L to Earth should be the same but is 110V and Neutral to Earth is 120V when it should be near zero.


    • Hi George and apologies for the late reply!
      As per my investigations, I’ve discovered that the DeltaPRO has multiple SoC that control different parts/components like the LCD, Inverter, Mppt controller, bms, etc…
      Each of these components can be updated separately or in a bundle. Sometimes the firmware update process has a partial failure where some components are updated to the latest while others are not. It would be nice if the Ecoflow APP would give more detailed info about the firmware update process and be more specific about what components are running what version of the firmware.
      What you see in your DeltaPRO is something I have also suffered in which not all components have the latest version of the firmware so I always tend to check multiple times after the initial update to make sure every single component has the latest firmware.
      TLDR; after the first update, check again to see if the APP offers you again the same update or not. If it does it means some components have updated and some have not so the DeltaPRO still is not 100% updated. Please launch again the update until the app says you’re OK. Failure to do so could lead to some weird issues or subpar performance.
      I have the European version for Spain with 230V/50Hz (so like yours) but I didn’t observe any issues at all (my digital meter/controller/filter/etc would have warned or freaked out). Actually even under heavy load the voltage is super stable and hovers around 228.1V which is tons better than the electric company where it can fluctuate from 208V to 232V…

  • I see today that v89 has been released. No info as to what it does. Perhaps it’s v85 again with a mod to make it work?

    • Thanks for reporting!
      I’ve seen it over at facebook but I will give myself a week before updating just in case as I’m still using V2.x APP.

  • Something that bothers me about these devices is the way the mains output is configured. I don’t know about Spain but in the UK, the Neutral (N) is bonded to Earth (E) at the supplier input to the consumer unit (main house fuse box). That way, the measured votalge between Live (L) and either N or E is 230v.
    When the Delta Pro is in pass through mode, the outputs are the same, L>E 230v, L>N 230v, N>E = minimal ie a volt or two due to losses in the Neutral house wiring.
    HOWEVER: When I’m drawing from the Delta Pro, in generation or EPS modes I find L>N 230v, L>E 110v, N>E 120v and this to me is potentially lethal! The Neutral, in gen or EPS modes ie a grid power failure is 120v ABOVE earth potential. It’s as if Ecoflow use the Earth as 0v and the mains supply of 230v is approximately plus 50% and minus 50% of 230v.
    I see Will Prowse, on his YouTube channel talks about how you must NOT bond the Delta Neutral to Earth. He did so and says he “blew up his Delta Pro”.
    This concerns me immensely as one could believe something is switched off or perhaps a device fuse has blown, say a TV set yet the innards of the device are still at 120v!
    Try yours and see if the EU versions are the same as UK.

    • Interesting… The first thing that comes to mind is “Floating Neutral” (facebook group posts) but I’ll make some time to test and reproduce your detailed steps and see if I get the same result.
      Will reply here with my findings and include in my next article (already passed 132 cycles!).
      Thanks for reporting!

    • Seems there are major issues with the DeltaPRO and FW .85 … multiple blown DPs among them mine… šŸ™

  • Wow! Just tried F/Ware update from 0.3.6 to 0.4.8 – What a NIGHTMARE!

    The update bar goes to about 50% then a button appears, labelled “CONNECT”. I clicked it and the only thing that happened was the Delta Pro vanished from my app.
    90 minutes later and after numerous attempts to reconnect to the unit, I finally tried in the app as “OTHER” instead of Delta Pro and it reappeared.

    Again I tried the update (glutton for punishment) and again the unit simply vanished. I even followed the Ecolflow YouTube b=guide running at 50% speed to ensure I was doing it right but again I simply could not get the unit to appear in the app. I finally tried it as an “OTHER” device and again it reappeared after 3-4 attempts.

    Now, I’m stumped as to where v 0.3.6 or indeed 0.4.8 came from when the last time I checked it was

    Needless to say, I shan’t be trying this update again.

    • Hi George, apologies for the late approval, somehow I didn’t get notified.
      Thanks for reporting such valuable information and sad that you had to go through all this ordeal… This sure erodes customer’s confidence in the product.
      After my DP went belly up while I was away from home (with all the anxiety that this potentially dangerous event entails) I then and there decided to not update anymore until 2122…
      The DP has become a critical component of “lower the utility bill” and for the upcoming “get ready for energy cuts” so I’ve decided to:
      1) Stay put and not do any update except if requested by EF engineers as a beta-test with guaranteed 48h replacement unit (brand new).
      2) Not use AT ALL “EPS/PASSTHROUGH” mode as it is finnicky and (currently) can lead to the DP going up in smoke.
      3) Have all the necessary protections in place coming out of the DP as in some cases I’ve seen a (short in time) voltage bump from 230V to 245V and fortunately I’ve managed to make a video of a similar event.
      I’m in the process of writing all my findings in the article I’m working on which will be the “6 months with the DP”.

  • Correction:

    Now, Iā€™m stumped as to where v 0.3.6 or indeed 0.4.8 came from when the last time I checked it was

    • Yes when I first read about update 0.x.x over FB I thought it was a typo but it was in the screen caps so…. yeah, for now not going to gamble and will stay away as a customer from updating.
      One of my (2) DPs is running original FW and it’s working PERFECT! I have everything runnning, with the app and have the program I’ve written (actually it’s already morphed into something big with webserver and tons of stats and juicy info) I’m super happy… so… don’t touch!
      On a bonus note, even the DP REMOTE works perfectly with FW which leads me to think that the DP was merely a conduit to update the remote and once the remote is updated it will run with ANY DP FW. šŸ˜€

      • Any chance to downgrade to FW ? I’m on BMS doesn’t work properly. I often need to recalibrate to DP manually because of decreased capacity. Thanks.

        • Hi Timo. As far as I know it is not possible to downgrade FW from user’s side :(.
          As for the “recalibration”, I will include a painless simple method of “recalibrating” that can be done in 15 seconds and without having to mistreat your battery pack in my upcoming “6 months” review (that I’m working on as we speak).
          PS: most of the advice that you read over at FB group is …. BS.
          After I publish the new article, I’ll be happy to reply there to all the questions šŸ™‚

        • Don’t request a firmware downgrade. I did this, and not all internal modules will successfully be updated. In my case, the Wifi/Bluetooth/front screen module became corrupted and my unit needed to be replaced. It still operated properly, without any app control so there’s no changing or any settings. (Plus the backlight on the front screen is now permanently off.)

          • Hi Rick!
            Oh WOW!… Really? that’s actually… scary… It would be interesting to do an RCA and know what went wrong with the downgrade. That being said, it is scary to know that if you do a downgrade you’d end up bricking (some components of) your unit… šŸ™
            The least you can expect if for EF engineers (and QA?) to know if there’s some sort of incompatibility in the case of a downgrade so thank you for taking the time to write about your experience and warn others not to go this route, myself included.

  • Seems I’ve now joined the growing band of exploding Delta Pro owners. I have to say, mine was in pass throug (EPS) mode at the time. It’s the second Delta Pro I’ve had explode and I’m really beginning to believe that Ecoflow ought to recall all of these units. I own FIVE Delta Pros both at my home and my partner’s home. I have had them timed to charge when least likely to be used, relying upon a combination of pass through when charging and EPS when not charging but perhaps I’ll do away with the timers and simply manually charge them and NOT use them in pass through mode. Pity because pass through mode is exactly why I bought them especially as my partner’s address often suffers blackouts from a few minutes to several hours.
    That said, Ecoflow staff seem to be keen to help and I’m awaiting a pre paid return label for the most recent banger right now.

    • It sucks to be in this situation especially for the distress and downtime this causes but at least EF own up to it and replace the unit asap once you mention .85 and error 121 so they are well aware of the problem and i’m pretty sure someone there (QA? Engineering?) is having a hard time after so many returns as this is very expensive in terms of money and brand.
      I’m hopeful that it was a big derp with .85 and they managed to fix it or at the least avoid the triggers of the issue and I’ll disclose some other juicy information in the upcoming article…. Let’s just say that at least there’s an upside to error 121… šŸ˜‰
      I would advise to sit tight for a few days and see how things play out now that has just dropped and ppl are updating to it. The release notes are a little bit confusing but the insider info that I have is that they’ve been working around the clock to solve this 121 RMA painful problem so…. hopefully their QA is better this time.

  • Bit of advice…. Perhaps best to NOT switch on the “Lab Features AC Always On” facility as this will lead to the unit automatically switching into pass through mode once AC charging is appled??? What are your views?

    • Well, that “lab feature” is only useful for when on EPS mode and the AC comes back again, to turn inverter in EPS mode as it was before.
      My hopes for this feature when it dropped was for the MPPT side and not EPS. I was hoping that if inverter turned off due to low battery, that it would automatically turn on when there was MPPT input and after a certain percentage (user settable) but it wasn’t so I just turned it off as I didn’t want to juggle with more (possible) bugs and my 121 happened with this setting off.
      I have a feeling that there are multiple issues at play here, the combination of which has proven to be fatal (just like airplane crashes) after .85.
      Now if we analyze the .85 release notes, the “Support power station grounding adapter” immediately jumps out and to me it might explain part of the issue (total speculation from my side!).
      I’ll include further details in the upcoming article.


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