EcoFlow’s DELTA 3 Plus and Smart Extra Battery: Product line impermanence curiosity

Denser batteries translate into notably smaller form factors, at least in some cases. The post EcoFlow’s DELTA 3 Plus and Smart Extra Battery: Product line impermanence curiosity appeared first on EDN.

Electronics Nov 11, 2025 0 3 Add to Reading List

EcoFlow’s DELTA 3 Plus and Smart Extra Battery: Product line impermanence curiosity

Earlier this summer, I detailed my travails struggling with (and ultimately recovering from) buggy firmware updates I’d been “pushed” on my combo of EcoFlow’s DELTA 2 portable power station and its Smart Extra Battery supplemental capacity companion:

Toward the end of that earlier writeup, I mentioned that I’d subsequently been offered a further firmware update, which (for, I think, understandable reasons) I was going to hold off on tackling for a while, until I saw whether other, braver souls had encountered issues of their own with it:

DELTA 2 firmware update success(es)

In late August, I eventually decided to take the upgrade plunge, after enduring the latest in an occasional but enduring series of connectivity glitches. Although I could still communicate with the device “stack” via Bluetooth, its Wi-Fi connection had dropped and needed to be reinstated within the app. The firmware update’s documentation indicated it’d deal with this issue:

The upgrade attempt was thankfully successful this time, although candidly, I can’t say that the Wi-Fi connectivity is noticeably more robust now than it had been previously:

I was then immediately offered another firmware upgrade, which I’d heard on Facebook’s “EcoFlow Official Club“ group had just been released. Tempting fate, I plunged ahead again:

Thankfully, this one completed uneventfully as well:

As did another offered to me in early September (gotta love that descriptive “Fixes some known issues” phrasing, eh? I’m being sarcastic, if it wasn’t already obvious…):

There have been no more firmware upgrades in the subsequent ~1.5 months. More generally, since the DELTA 2 line is mature and EcoFlow has moved on to the DELTA 3 series, I’m hopeful for ongoing software stability (accompanied by no more functional misbehavior) at this point.

Initial impressions of DELTA 3 devices

Speaking of which, what about the DELTA 3 Plus and its accompanying Smart Extra Battery, mentioned at the end of my earlier write-up, which EcoFlow support had sent as replacements for the DELTA 2-generation predecessors prior to my successful resurrection of them?

Here again is what the new DELTA 3 stack (left) looks like next to its DELTA 2 precursors (right):

The stored-charge capacity of the DELTA 2 is 1024Wh, which matches that of the DELTA 3 Plus. I’d mentioned in my earlier DELTA 2 coverage that the DELTA 3 Plus was based on newer, denser (but still LiFePO₄ aka LFP) 40135 batteries. Why then do the two portable power stations have nearly the same sizes? The answer, of course, is that there’s more than just batteries inside ‘em:

The (presumed) varying battery generation-induced size differential is much more evident with the two generations of Smart Extra Batteries…which are (essentially) just batteries.

Despite their 1,024-Wh capacity commonality, the DELTA 3 version (again on top of the stack at left in the earlier photo) has dimensions of 15.7 x 8 x 7.8 in (398 x 200 x 198 mm) and weighs 21.1 lbs. (9.6 kg).

Its DELTA 2-generation predecessor at top right weighs essentially the same (21 lbs./9.5 kg), and it’s nearly 50% taller (15.7 × 8.3 × 11.1 in./40 × 21.1 × 28.1 cm).

By the way, back when I was fearing that the base DELTA 2 unit was “toast” but hoping that its Smart Extra Battery might still be saved, I confirmed EcoFlow’s claim that the DELTA 3 Plus worked not only with multiple capacity variants of the DELTA 3-generation Smart Extra Battery, for capacity expansion up to 5 KWh, but also with my prior-generation storage capacity expansion solution:

Charging (and other) enhancements

Aside from the height-therefore-volume differential, the most visually obvious other difference between the two portable power stations is the relocation of AC power outlets to the front panel in the DELTA 3 Plus case. Other generational improvements include:

Faster sub-10-ms switchover from wall outlet-sourced to inverter-generated AC for more robust (albeit not comprehensive…no integrated surge protection support, for example) UPS functional emulation
Improved airflow, leading to claimed 30-dB noise levels in normal operation
A newer-generation battery-induced boosted recharge cycle count to 4,000
Inverter-generated AC output power up to 3600 W (X-Boost surge)
Higher power, albeit fewer, USB-A ports (two, each 36 W, compared to two 12 W and two 18 W)
Higher power USB-C ports (two, each 140 W, versus two 100 W)
And faster charging (sub-1-hour to 100%), enabled by factors such as:
- AC input power up to 1500 W
- Solar input power up to 1000 W (two 500-W-max XT60i connectors) with maximum power point tracking (MPPT) support
- And simultaneous multi-charging capabilities from solar and AC when both are available, prioritizing the former to save money.

Speaking of solar, I haven’t forgotten about the two 220W panels:

And a more recently acquired 400W one:

For which I’m admittedly belated in translating testing aspiration into reality. The issue at the moment isn’t snow on the deck, although that’ll be back soon enough. It’s high winds:

That said, my procrastination has had at least one upside: a larger number of interesting options (and combinations) to evaluate than before. Now, I can tether either the two parallel-connected 220-W panels or the single 400-W one to the DELTA 2’s single XT60i input.

And for the DELTA 3 Plus, thanks to the aforementioned dual XT60i inputs and 1000-W peak input support, I can hook up all three panels simultaneously, although doing so will likely take up a notable chunk of my deck real estate in the process. Please remain on standby for observations and results to come!

More on charging and firmware upgrading

Two other comments to note, in closing:

Speaking of the XT60i input, how do I charge the DELTA 3 Plus (or the DELTA 2, for that matter) in-vehicle using EcoFlow’s 800W Alternator Charger (which, yes, I already realize that I’m also overdue in installing and then testing!):

Specifically, when the portable power station is simultaneously connected to its Smart Extended Battery companion? Ordinarily, the Alternator Charger would tether to the portable power station over the XT150 connector-equipped cable that comes bundled with the former:

But, in this particular case, the portable power station’s XT150 interface is already in use (and for that matter, isn’t even an available option for lower-end devices such as my RIVER 2):

The trick is to instead use one of the two orange-color XT60i connectors also shown at the bottom left of the DELTA 3 stack setup photo.

EcoFlow alternatively bundles an XT60 connector-equipped cable with the 500-W version of the Alternator Charger, intended for use with smaller vehicles and/or more modest portable power stations, but that same cable is also available for standalone purchase:

It’ll be lower power (therefore slower) than the XT150 alternative, but it’s better than nothing! And it’ll recharge both the portable power station and (via the separate XT150-to-XT150 cable) the tethered Smart Extended Battery. Just be sure to secure the stack so it doesn’t tip over!

Also, regarding firmware upgrades, I’d been pleasantly surprised to not receive any DELTA 3 Plus update notifications since late April when it and its Smart Extra Battery companion had come into my possession. Software stability nirvana ended, in late August, alas, and since the update documentation specifically mentioned a “Better experience when using the device with an extra battery,” I decided to proceed. Unfortunately, my first several subsequent upgrade attempts terminated prematurely, at random percentage-complete points, after slower-than-usual progress, and with worrying failure status messages:

Eventually, I crossed my fingers and followed the guidance to restart the device, a process which, I eventually realized after several frustrating, unsuccessful initial attempts, can only be accomplished with the portable power station disconnected from AC. The device was stuck in a partially updated state post-reboot, albeit thankfully still accessible over Bluetooth:

And doubly thankfully, this time the upgrade completed successfully to both the DELTA 3 Plus:

And its tethered Smart Extra Battery:

Phew! As before with the DELTA 2, I think I’ll delay my next update (which hasn’t been offered yet) until I wait an appropriate amount of time and then check in with the user community first for feedback on their experiences. And with that, I await your thoughts in the comments!

—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.