Power station Ecoflow Delta 2 Max in the test: 5 year guarantee, robust and quiet

Solar generators with integrated batteries allow self-sufficient power supply away from the power grid. Thanks to the many connection options, including a 230 V socket and a sufficiently high continuous output, the mobile power storage units are ideal not only for camping holidays and leisure activities, but also for trade fairs and emergency power supply. Recharging can be done either via the power supply or with the help of photovoltaic panels. Thanks to the quick charging function, the models in the Delta series are 80 percent charged in less than an hour.

As usual from EcoFlow, the EcoFlow Delta 2 Max arrives to us neatly and securely packed. At first glance it looks like the evolved Delta 2 (test report). In contrast, the dimensions of the Delta 2 Max are 21 x 40 x 28 cm (W/L/H) instead of 50 x 24 x 31 cm and weigh around 23 kg and 12 kg for the Delta 2. Thanks to the handles on both sides the power station becomes maneuverable, but due to its heavy weight it is not suitable for moving long distances. If you want to transport the Delta Max 2 more comfortably, you should buy a hand truck.

The design looks modern and the workmanship is of very high quality. Unlike many other manufacturers, EcoFlow does not use bright and attention-grabbing colors and therefore this mobile socket also fits in at a trade fair stand or in the office, not just on a campsite or festival. Large rubber feet ensure a stable stand. The housing with open ventilation slots is not waterproof. This is the case with all power stations, but we would like at least protective covers for the USB ports and sockets so that no moisture can enter the connections when you place the Delta 2 Max in the grass.

The various inputs and outputs, function keys and status display are spread out on three sides and are not arranged centrally. The status display is located at the top of the front, which includes a total of six USB ports, their power button and an on/off button. In addition to a total of four USB-A ports (2x 12 watts, 2x 18 watts), there are two USB-C ports with up to 100 watts of power delivery. You can also communicate with the power station via WiFi and Bluetooth and use the app to change various settings, turn outputs on and off or monitor performance data.

The power station’s fuses as well as the inputs for the solar panels and power cables are hidden behind a plastic flap in the middle above the four 230 V sockets at the rear. There is also a small slide switch here that can be used to reduce the charging power of the power station. Below the Schuko sockets are a 12 V car connection with 10 A (cigarette lighter) and two 12 V round sockets with a maximum of 3 A. The 12 V consumers have their own illuminated power button and are controlled independently of the USB port. The inputs for optionally available additional batteries are located behind two small flaps on the right side of the housing. With their help, the capacity of the Delta 2 Max can be increased threefold to 6 kWh.

When it comes to power storage, the manufacturer is again using long-lasting LiFePO4 batteries. EcoFlow promises that after 3000 charging cycles, more than 80 percent of the nominal capacity of around 2048 Wh should still be available. If used daily, the power station will last for around 10 years. In addition to the power station, the delivery also includes a 12 V cable, a power cable for charging from a socket and a car charging cable. An adapter cable for MC4 connectors for connecting the solar panel is not included. You don’t need a bulky external power supply here.

Using and controlling the Delta 2 Max is self-explanatory thanks to the clear labelling and intuitive operation. After plugging in the power cable or solar panel or switching on the power station, the status display turns on and shows the values ​​of the input and output power, the current capacity in percentage and the remaining running time calculated with continuous consumption. Which outputs are currently on can also be seen on the display. The display turns off automatically after a few minutes. If you now want to ask about the values, press one of the buttons briefly and the display turns on again. A small LED in the corresponding power button also shows whether the outputs are currently active or not.

First, we fully discharge the Delta 2 Max and perform our first performance test. The connected consumers, whether with direct or alternating current, work properly without any abnormalities due to the pure sine waves.

Charging classic USB gadgets such as cell phones or action cameras works just as smoothly as supplying our power-consuming MacBook Pro with PD up to 100 W via USB-C. Medium-power consumers such as drone chargers, compressor coolers, gaming PCs, medium tools or lamps are not even remotely out of place with the Delta 2 Max. The power station also supplies powerful consumers such as reciprocating saws, electric grass trimmers and electric chainsaws without any problems. Even an 1800-watt kettle works reliably thanks to the energy buffer provided by the so-called X-Boost (up to 3100 watts). We push the Delta 2 Max to its limits with our cross-cut saw with a starting current of just over 3500 watts. So far we have only been able to operate it with the EcoFlow Delta Pro. In the event of an overload, the corresponding outputs of the Delta 2 Max are switched off immediately and reliably.

Now it’s time to charge the empty battery. To do this, we first use the internal power supply. When connected to the socket, the Delta 2 Max immediately picks up speed, but the noise level lags far behind the Delta 2 (test report) or Delta Pro (test report), which are much louder during charging, even with an input power of over 2100 watts. Within just half a meter we measured around 41 to 42 dB even at full power. Other models easily reach 55 dB and more. With a lower charging power (400 watts), the charging time is extended, but the volume is also reduced to around 32 to 35 dB.

But not only the volume, but also the charging performance is impressive. After just under an hour (53 minutes in the test), the Delta 2 Max’s batteries are already 80 percent charged. It takes us about an hour and a half (91 minutes) to reach 100 percent. An excellent value for such a high capacity. Many power stations, even quite weak ones with low capacity, such as the EBL MP500 (test report), require six to eight hours to charge using a power supply.

Charging via photovoltaics also works at up to 1000 watts. Equipped this way, the Delta 2 Max will take a little less than three hours to charge via solar power – provided the weather is good.

During the subsequent long-term tests, we check how much power we can actually get from the Delta 2 Max in practice. How high the conversion losses actually are depends mainly on the connected consumers. The yield in the test was highest when using a powerful consumer with 230 volts. When a fan heater with an output of up to 1800 watts was connected, about 1860 Wh flowed, which corresponds to a yield of about 91 percent in terms of the nominal capacity – an excellent value. When connecting a PC workstation and a few small consumers (80 watts to 120 watts in total), we still get about 1702 Wh, which still corresponds to 84 percent of the nominal capacity. The biggest losses occurred when using a 230 V socket and some weak lamps with a power of less than 30 watts. Only around 1515 Wh flowed here, which corresponds to about 74 percent of the nominal capacity. The Delta 2 Max supplies our workplace with a MacBook Pro, two 24-inch monitors, printer and telephone (around 120 watts to 140 watts) for two consecutive working days and produces around 1720 Wh, which corresponds to a loss of 16 percent. This is in line with the around 85 percent usable capacity quoted by most manufacturers.

If the output power exceeds 100 watts, the internal fans turn on during the test. With lower power, the Delta 2 Max is generally silent. The fans only spin sporadically for short periods of time. Although these noises are audible, they are still noticeably quieter than many other power stations. Even with more than 400 watts of power output, the volume is comparable to that of a classic office PC. At higher power the fans also turn on, but overall the noise level remains tolerable. If you want to sleep in a tent right next to it, you should stay at a power below 100 watts, then the power station is practically silent. Here a connected compressor cooler will usually make quite a loud noise.

Charging and discharging the Delta 2 Max at the same time is possible without any problems. However, the UPS function that is heavily promoted on the Delta 2 is not there here. In tests, the switching time was not enough to keep our gaming PC running.

In the past, we always felt that using an app was unnecessary. Remote status monitoring can be useful, but we don’t really need it. However, we believe it is ideal that you can make many settings on the power station using the app. For example, we disable the status tone and change the automatic switch-off time for the output and display. In addition, you can limit the usable capacity or reduce the charging power. This means that the user can choose between full performance and careful use of the battery.

At the time of testing, the EcoFlow Delta 2 Max was available for 1,760 euros. Now you can carry them around 1500 Euros. Optional batteries cost $3 each 839 euros. The price is high, but justifiable considering the premium features. The Delta 2 was originally offered for just under 1200 Euros, but now costs less than 900 Euros. So it might be worth waiting and hoping for a price drop.

The EcoFlow Delta 2 Max is perfect for those for whom the power and performance of the Delta 2 (test report) is not enough. At 2400 watts, it is slightly weaker than the Delta Pro XL Power Station (test report), but it is also significantly more compact and cheaper.

If you are looking for a compact but powerful power station for use with solar modules or as an emergency power supply, then the EcoFlow Delta 2 Max is better for you. The Delta series is also an excellent choice when it comes to short charging times and long service life. The battery can also be optionally extended and the most important settings can be customized via the app.

The fans can also be heard in this solar generator, but their volume – unlike the sister models – is perfectly suitable for everyday use. Even at full charging power, the Delta 2 Max makes pleasantly little noise. It’s a pity that the exhaust doors are unprotected and therefore potentially sensitive to moisture.