EcoFlow Delta 3 Series: Five New Power Stations Previewed

Introduction

EcoFlow launched the Delta 3 and Delta 3 Plus in 2024, and many users have been waiting for a Delta 3 Max. The Delta 2 Max was one of the best jack-of-all-trades portable power stations on the market, so expectations were high. The wait is now over. EcoFlow has launched not just the Delta 3 Max, but five new power stations in the Delta 3 series: the Delta 3 Classic, the Delta 3 Max, the Delta 3 Max Plus, the Delta 3 Ultra, and the Delta 3 Ultra Plus.

This preview covers all five models, with detailed testing of the flagship Ultra Plus model to find out one important thing: are they any good?

The Delta 3 Lineup at a Glance

All Delta 3 series models use lithium iron phosphate batteries, rated to at least 4,000 cycles to 80% capacity, which translates to more than 10 years of lifespan. The Classic, the smallest model, offers a 1 kWh battery. The Max and Max Plus offer a 2 kWh battery. The Ultra and Ultra Plus offer a 3 kWh battery.

Size and weight vary across the lineup. The Classic is approximately 27 lb and measures 16 x 8 x 11 in. The Max and Max Plus weigh 44 to 48 lb respectively and measure 19 x 10 x 12 in. The Ultra and Ultra Plus weigh 72 to 74 lb respectively and measure about 25 x 3 x 16 in.

The Classic is the only outlier when it comes to the display. It uses the previous generation screen, which is smaller and a little more difficult to read than the other four. The other models feature what could be called a parentheses display, with two curves on each side of the number that light up and animate. The Classic has an old-fashioned circular display. All models show similar information, including input, output, watts, time to charge, discharge, battery percentage with icon, and dozens of other data points covered in each model’s manual.

Inverter and Outlet Configurations

The Classic packs an 1,800 watt pure sine wave inverter with three outlets. The Max and Max Plus both have four 20 amp outlets. The Max has a 2,400 watt inverter, while the Max Plus has a 3,000 watt inverter.

The Plus models have a notable feature: the outlets are split. One AC button lights up two outlets, and another AC button lights up the other two. This allows you to set up output priority within the app, where certain outlets can automatically turn on or off depending on the battery’s state of charge. For example, if you have a refrigerator plugged into one side and an air conditioner plugged into the other, you can set it so that when the battery discharges to 50%, it shuts off the air conditioner to save power while the refrigerator side stays on. This feature is only available on the two Plus models.

The Ultra and Ultra Plus both pack a 3,600 watt inverter through four 20 amp outlets, and both have a TT30R 30 amp RV hookup. The Ultra Plus splits the outlets, with two on AC1 and three on AC2.

Charging Options and Solar Input

The Classic can AC charge at 1,400 watts and solar charge at 500 watts with a single 12 to 60 volt MPPT controller. It takes about 2 and 1/2 hours to charge from AC and about 5 hours from solar.

The Max and Max Plus can both charge at 1,800 watts from AC power in less than 90 minutes. The Max has a single 500 W 12 to 60 volt MPPT controller, while the Max Plus duplicates that for two 500 W MPPT controllers, totaling 1,000 watts. The Max can charge with solar in about 5 hours, while the Max Plus cuts that in half.

The Ultra and Ultra Plus both charge from 1,800 watts AC power in about 2 hours. The Ultra sports a single 800 W 12 to 60 volt MPPT controller, while the Plus version duplicates that for two 800 watt MPPT controllers, totaling 1,600 watts of solar charging. The Ultra can charge via solar in about 5 hours, while the Plus version again cuts that in half.

All Delta 3 models can also charge from 12 or 24 volt vehicle power if you purchase the appropriate cable. Note that the only cable included with any of these power stations is the AC charging cable. No solar cables are provided.

For 12 volt output, the entire Delta 3 lineup offers a regulated 12 volt DC output in the form of a vehicle accessory socket, located on the back. The two Plus models, the Max Plus and Ultra Plus, also offer a 30 amp 12 volt Anderson power pole output for running high amp DC appliances or for wiring into fuse boxes in van or RV builds.

For USB outputs, the Classic offers a 100 watt USB-C, a 30 watt USB-C, and a single 18 watt USB-A quick charge port. The Max has one 100 watt and one pair of 30 watt USB-C ports with a single 18 watt USB-A quick charge port. The Max Plus ups that by offering a 140 watt and a pair of 45 watt USB-C ports with the same single 18 watt USB-A. Both the Ultra and Ultra Plus have a 140 watt USB-C port and a pair of 45 watt USB-C ports with a single 18 watt QC port. None of the series offers bidirectional USB; these are all output only.

Battery Expansion

Only the Max Plus and Ultra Plus offer battery expansion ability through their included external battery ports, which EcoFlow calls the 4 plus 8. The Max Plus can use either the Delta 3 batteries, the Delta Pro 3 battery, or the Delta 2 Max battery for expansion up to 10 kilowatt hours. The Ultra Plus can use the Max Plus extra battery or Delta Pro 3 battery for expansion up to 11 kilowatt hours.

These external battery ports also double as fast charge ports for EcoFlow’s 1,000 watt alternator charger. With future upgrades, you could plug into several different models of batteries as well as their smart home panel system. So, you may decide to choose one of the Plus models if you want battery expansion in the future or possibly plug them into your home.

The entire Delta 3 series comes with a 5-year manufacturer’s warranty.

Flagship Testing: EcoFlow Delta 3 Ultra Plus

The flagship Delta 3 Ultra Plus was put through detailed testing. The AC battery capacity test scored 2,690 watt hours out of 3,072, which is an above average 88%.

For idle consumption, when the DC was left turned on with nothing plugged in, it used only 5% of the battery over 24 hours. That is 154 watt hours or a little over 6 watts of wasted power at DC idle. If you left the DC turned on, it would take about 20 days to kill the battery.

For AC consumption, with the inverter enabled for a full 24 hours, it used 15% of the battery, which is about 460 watt hours wasted or approximately 19 watts of idle consumption for the built-in 3,600 watt inverter. If you left the inverter on at 19 watts of idle consumption, it would totally kill the battery in about 6 and 3/4 days. 19 watts out of a 3,600 watt inverter is pretty good and about average.

When recharging the battery using the solar port back to 100%, it took 574 watt hours at 8 amps to recharge. Since it used 574 to recharge instead of the expected 460, that gives an 80% efficiency for the MPPT controller. That means 20% of the power pumped into the solar is wasted to heat. An 80% efficiency for a solar controller isn’t really that great; 90% or better would be preferred.

The pure sine wave check under load was 118 volt 60 Hz, which is a pass. The inverter capacity test on the 3,600 watt inverter pushed 4,600 watts for just under 5 seconds, which is a pass.

The 5-minute sustain cooling or heat soak test ran the 3,600 watt inverter at its maximum for at least 5 minutes. It worked absolutely fine with nothing out of the ordinary. The only concern was that the fan is pretty loud, measuring 60 dB from a meter away. This is unusual for EcoFlow, as most of their products in recent years have been really quiet.

For appliance tests, a 5,000 BTU air conditioner consuming 300 watts, a 1,800 watt heat gun, and a saw were run simultaneously, hitting 3,000 watts with no problem.

Max rate AC charging has a slider in the app that allows you to configure from 200 to 1,800 watts of charging. At 1,800 watts, it was pulling about 1,740 watts. The fan was spinning but very quiet. If you select optimized charging in the app, that is 500 watts, and quiet charging is 200 watts.

The DC solar input range on the Ultra Plus is 12 to 60 volts at 18 amps, 800 watts, multiplied by two because it has two MPPT controllers on the back. When hooked up to 12 volts, it delivered 225 watts. At 24 volts, it delivered 450 watts. At 48 volts, it delivered 800 watts. At the max of 62 volts before it cut off, it delivered 800 watts again.

For charging fan noise, when charged with AC power on maximum, it registered 42 dB on the sound meter. When run on quiet or solar charging, it didn’t register at all.

For simultaneous charging, it pushed 800 watts of solar in along with 1,800 watts of AC power combined for 2,600 watts, and it may be higher if you plug solar into the second MPPT port.

The UPS test determined whether the inverter can switch from grid to battery fast enough to keep a full PC computer running without locking it up. The computer ran just fine with no problems, and it passed.

For DC output at max rate, the 10 amp car port delivered 10 amps at 11.6 volts. A 1,000 watt inverter plugged into the Anderson output pulled 355 watts for over 6 minutes, which is a pass. The 12 volt output is regulated at 12.9 volts.

For USB output check, it pulled 140 watts and 45 watts simultaneously from the USB ports, which was a pass.

The amplifier interference test determined whether the inverter is clean or dirty, meaning whether it makes pops, clicks, and buzzes out of an amplifier. It was perfectly clean with no problem.

The EMF test was very impressive, with no interference picked up on an AM radio. With Wi-Fi and Bluetooth enabled by default, the power station at idle registered only around four or five. With the inverter on, it didn’t pick up any interference even a couple inches away from the outlets. EcoFlow did a great job of shielding this inverter. If you are worried about EMF interference in the area where you will use this, such as with a pacemaker or ham radio, this shouldn’t cause any interference.

App and Smart Features

EcoFlow offers a Bluetooth and Wi-Fi app that can do just about anything. It is pretty much the best app in the industry. You can do everything from turning things off and on remotely anywhere in the world to setting up UPS mode. The unit can turn off and on at certain times of the day depending on solar priority. It also has the option to turn the ports back on after the battery dies and you apply charging to it. This is a very big feature that EcoFlow was one of the first to implement. If you kill the battery running a refrigerator at 6:00 a.m., the sun comes up at 8:00, starts charging the battery, and at about 10% charge the outlets will turn themselves back on automatically and power your fridge again.

Things to Consider

While the Delta 3 series is strong overall, there are a few questionable design decisions. The Ultra models don’t offer higher voltage solar charging. Getting 1,600 watts out of 60 volts isn’t the easiest thing to do with solar panels. They do give you a decent 18 amp limit to work with on each MPPT controller, but that also means you need to buy and use Y adapters to put panels in parallel instead of series. Anything that is 3 kilowatt hours or larger should offer a minimum 150 volt MPPT for using larger panels in series, because that is what most people with larger power stations are going to do. MPPTs prefer higher voltage, and that would help with the somewhat low 80% efficiency.

The naming convention for these products is confusing at best. You have the Delta Pro 3, a Delta Pro Ultra, and now a Delta 3 Ultra. To top it off, you have Plus models now, which aren’t necessarily larger but just have more features. EcoFlow used to use battery size like Delta 1300 or Delta Max 2000 to distinguish models. That is a lot easier to remember and comprehend than everything just being Deltas, Pros, Max’s, and Ultras. A customer isn’t going to know if a Pro is better than an Ultra or if an Ultra is better than a Max.

Buying Advice

The Delta 3 series offers a clear progression from the compact Classic to the feature-rich Ultra Plus. The Classic is the most budget-friendly option with a 1 kWh battery and an 1,800 watt inverter, making it suitable for basic backup power needs. The Max and Max Plus step up to 2 kWh batteries with larger inverters, and the Plus adds split outlets and battery expansion. The Ultra and Ultra Plus offer the most power with 3 kWh batteries and 3,600 watt inverters, plus the RV hookup and the highest solar input capacity.

If you want a compact unit for essentials like a refrigerator or small appliances, the Classic covers the basics. The Max is a solid middle ground with a 2,400 watt inverter and fast AC charging.

The Max Plus adds the split outlet feature, a 3,000 watt inverter, dual MPPT controllers, and battery expansion up to 10 kilowatt hours. This makes it a strong choice if you want flexibility for future expansion.

The Ultra offers the same 3,600 watt inverter as the Ultra Plus but with a single MPPT controller and no battery expansion. It is a good option if you need high output without the extra features.

The Ultra Plus is the flagship, with dual MPPT controllers, split outlets, battery expansion up to 11 kilowatt hours, and the best overall performance in testing. It passed every test, including the UPS test, amp interference test, and EMF test.

Conclusion

The EcoFlow Delta 3 series delivers a comprehensive lineup of portable power stations with lithium iron phosphate batteries, fast charging, and a 5-year warranty. The Ultra Plus flagship passed every test with flying colors, showing strong inverter performance, clean power output, and low EMF interference. The main drawbacks are the lack of higher voltage solar input on the Ultra models and the confusing naming convention. If you are looking for a portable power station, the Delta 3 series offers a model for nearly every need, from the compact Classic to the powerful Ultra Plus.