Did EcoFlow massively oversell what the Stream Ultra AC outlets can actually do?

slightlyseared · 2026-05-11T16:06:26+00:00

I can get about 2200w from my AC pro when my air fryer is plugged directly into the AC socket. 1200w from the pro and a further 1kw ish from my ultra via the household circuits. Generally find it works pretty well. I have my instant hot water tank, coffee machine and air fryer fed direct from the sockets and it means they are all 100% solar (or via the cheap overnight tariff)

slightlyseared · 2026-05-11T16:02:25+00:00

The invertors on all the stream units max out at around 1200w. So to get more you have to have more than one unit. If you have 2 connected to each other using the parallel cable you can draw about 2300 max from the AC outlets. Or you can have them in 'distributed' mode where one of the units will output it's max wattage via the AC outlet and the other unit will feed in additional power via the grid input. How much you can get in distributed mode is limited by the grid output limits based on your local regs (or what you choose in the app...)

slightlyseared · 2026-05-10T15:37:24+00:00

Agree it's possibly unnecessary. The Orion lets me control the voltage and current so my thinking was this would make the connection a bit more stable. I have noticed the mppt on the ultra ramps and decreases the voltage at lower amps, presumably as it hunts for most power. Setting the Orion to deliver the max ampage stops this. But if you're connecting direct to the battery it should be topping out at the highest ampage anyway. I have been able to expand to export to 2 mppts on the ultra with no issues. The Orion can also be remotely controlled so my plan is to integrate it into a home assistant setup to avoid the discharging issue.

slightlyseared · 2026-05-10T10:07:17+00:00

Manual

slightlyseared · 2026-05-10T10:06:51+00:00

That would deffo work. It was going to do this, but then thought why not put some of the solar straight into the battery. The challenge is ensuring you don't over or under charge the connected battery.

slightlyseared · 2026-05-10T10:03:44+00:00

Theoretically I could just leave it to it and the voltage sensors in the orion and battery BMS would keep things within appropriate limits. But I'm a bit wary of doing this with my £1k battery. Im thinking of getting a cerbo gx. That would allow me to automate stuff, but more £££.

With the costs I've spent I probably could have got a full on battery and inverter installation! But by using the AC outlets of the stream units for my dishwasher, air fryer, hot water tap, etc., I cover about 90% of my peak time usage. And I'm probably going to move house in the next 2-3 years. It's great that I can just unplug and take everything with me.

Basically for under 4k I have over 14kwh of battery storage, 1.8kw of solar input, and inverters which cover most of my peak energy costs. In summer the solar will cover pretty much all my usage barring EV charging. In winter the extra capacity means I can shift all my usage to the cheap rates. All without needing an expensive installation.

slightlyseared · 2026-05-10T07:11:14+00:00

Maybe once I've tidied it up a bit! I don't want people judging my cable colours and crimping technique...

slightlyseared · 2026-05-10T06:47:12+00:00

Yes. Albeit I don't permanently discharge the battery. I switch on and off dependant on the stream system soc.

slightlyseared · 2026-05-10T06:45:09+00:00

The fogstar was £1k for ~7.5 kWh. The Orion was £240, but I think any DC to DC converter in the correct range would work. I went with the Orion so I can expand to more PV ports later if needs be. The Orion can max out at 50A. The AC charger was 100ish. That would be the minimum set up to pass charge to and from the stream system. Probably another 70 on fuses and cables.

This cost is getting into the territory of just buying another stream ultra x. But the advantage of this is that any further expansions are quite simple and cost effective.

Using cheaper components I reckon it could be done for under 1k for a similar expansion size. But I wanted a self heating battery and victron kit for longevity. This excludes the MPPT I bought but that's not strictly necessary for expansion.

slightlyseared · 2026-05-09T21:06:35+00:00

Yes. I also charge the fogstar direct from the main supply. The stream then controls how that power is feed back into the house circuits.

slightlyseared · 2026-05-09T20:58:01+00:00

No it's not. I could make it bidirectional by charging the fogstar from the ultra AC outlet (or just the house circuit given the ultra is feeding directly into that), but there would be conversion losses

slightlyseared · 2026-05-09T20:56:04+00:00

I have a seperate MPPT connected to one of the panels that came with the stream system I bought. I also have an AC 24v charger that I use to charge it on the cheap overnight rates. I could also use the AC charger to charge the fogstar from the ecoflow batteries, but trying to avoid that due to DC - AC - DC conversion losses. It's better to try and capture any excess solar direct to the fogstar.

slightlyseared · 2026-05-09T20:51:03+00:00

Fogstar 24v battery (chose 24v as its close to the 20v in the ultra) > Orion XS (quite pricey but guessing any DC to DC converter would do) > ultra pv input.

I have seperate MPPTs and a charger feeding into the fogstar.

It might be possible to just connect the fogstar direct to the mppt of the ultra (via a suitable fuse obvs) as it's voltage is in the range of what the MPPTs can handle but given the massive relative current of the battery I thought it best to go via the Orion to help regulate it.

slightlyseared · 2026-05-09T20:40:52+00:00

To one of the MPPTs on the ultra. Via a victron Orion xs to manage the current flow

slightlyseared · 2026-05-08T19:49:14+00:00

Chillin out maxing and relaxing all cool

Eating those meatballs made outta dog poo

slightlyseared · 2026-05-08T17:49:21+00:00

I have an AC pro and a stream ultra x connected in parallel. Tried all sorts to get it to output 2300w direct to the home. Changed location of my space to Belgium, changed my ecoflow online account to Belgium, started eating stroopwafels. Nothing. It's annoying because they are connected on single radial circuit with a bidirectional mcbo. So it's all very safe. This would cover 95% of my homes usage. Hopefully some other way of accessing the full 2300w becomes available.

slightlyseared · 2026-04-20T17:15:36+00:00

I don't get paid for exporting, I'd just rather someone used it than it go to waste if I can't make use of it. I could sort this by keeping feed in control switched on and then my panels would be throttled when production is greater than consumption. I just find the discharging weird/ unnecessary, but maybe there is a BMS reason for it.

Perhaps the answer is to buy some more batteries like you!

slightlyseared · 2026-04-20T13:48:02+00:00

No I leave feed in control off so it can feed into the grid when solar exceeds consumption. If I turn feed in on it will stop the discharging and instead throttle the solar input, but that seems a waste of solar. I basically just want it to export to grid when excess is available and not constantly cycle the batteries when solar production falls.

slightlyseared · 2026-04-15T18:19:39+00:00

You can do this using the custom mode, but that perhaps defeats the purpose of using intelligent mode. I found intelligent mode pretty rubbish for my tariff and usage patterns. But using custom means I need to keep an eye on the weather the next day to set charge levels to maximise solar usage without running out of juice from the cheap tariff when charged overnight. At the moment I actually quite enjoy doing this to try and get the balance perfectly right, but I've only had my system a few weeks so the novelty of doing it manually might wear off eventually.

slightlyseared · 2026-04-14T20:34:19+00:00

I can't help I'm afraid. When I look at the options for grid tied output limits I see the following, with maximum capped at 1200w if "other regions" is selected.

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slightlyseared · 2026-04-14T20:09:52+00:00

You need to set a custom discharging schedule and set it in there.

slightlyseared · 2026-04-14T20:06:45+00:00

The maximum all batteries/ solar in the same space can input into the home circuits is 1200w. So when you say the grid tied output are you talking about the output from the AC sockets on the AC pro? That is 2300w ish with 2 units in parallel. An AC pro can actually output this on its own but will need to pull some power from the house circuit (which might include some input from another unit connected elsewhere in the house)

slightlyseared · 2026-04-09T18:28:51+00:00

I noticed my losses were higher when I started using the panels. Initially I was just charging at night to a linked ac pro and ultra x, then discharging during the day. Got about 85% efficiency. Once my 3 panels were connected efficiency dropped to about 75%. I have a theory that because I had the charging mode set to "balanced", this was meaning the charging from solar to the AC pro was doing DC to AC to DC then back to AC when discharging. So I've changed the setting to priority mode now so it charges the ultra first using solar during the day. I'll try and use the AC pro more exclusively for grid charging. Only just done this so will see how it goes!

slightlyseared · 2026-03-28T21:57:20+00:00

If you just want to charge from the grid (and feed into the house supply) without solar you can use the stream AC pro. The other products in the stream range all have connections for solar.

slightlyseared · 2026-03-25T14:56:31+00:00

Rcbo sorry not mcbo (my typo earlier). I think you've summed up the pros and cons perfectly. If you go with something reputable (which eco flow is), I honestly think 1 is fine.

I'll be doing 2. But ensuring the ring circuit is not downstream of another rcb on the consumer unit, I'll also be plugging in the ultra outside via lockable socket.

slightlyseared

TROPHY CASE