Theoretically speaking, you can connect as many DELTAs in serial (but not in parallel) as you want. However, the efficiency of the machines will be seriously compromised (The energy consumption of the inverters grows with the number of the connected machines). As a result, we do not recommend to connect more than 3 DELTAs in serial, and it is necessary to fully charge every DELTA before you connect them together. Moreover, connecting DELTA in serial will not increase the rated output, but will expand the capacity.

DELTA can be recharged through your car port and power your devices simultaneously.

When DELTA is charged through the AC and DC port at the same time, it will prioritize taking in power through the AC port. After you plucked out the AC cable, DELTA will start taking in electricity through the DC port.

DELTA can be recharged to 0%~80% in 1 hour, and be fully recharged in 1 hour 40 minutes.

DELTA can be fully charged through a 13.6V car port in 10-12 hours.

At perfect sunlight:
a. 1x 110W solar panel: 14-28 hrs
b. 2x 110W solar panel (in series): 7-14 hrs
c. 3x 110W solar panel (in series): 5-10 hrs
d. 4x 110W solar panel: 4-8 hrs
DELTA supports solar input ranges from 10V to 65V with a maximum allowed current of 10A and maximum input of 400W. 

In the Noise Test Chamber
Test condition:
1. Noise Tester: TES-1357
2. Ambient noise: 33.8dB
3. Test outcome: the average outcome from the front, back, right, and left
Test results:
Condition 1: AC outlet: <500W; the fan: 10% full speed, <40DB, 2-meter distance; Condition 2: AC outlet: 500W-1200W; the fan: 30% full speed, <45DB, 2-meter distance;
Condition 3: AC outlet: >1200W; the fan: 100% full speed, <50DB, 2-meter distance 

Discharge Temperature Range: -4-113°F (-20-45°C)
Recharge Temperature Range: 32-113°F (0-45°C)
When the ambient temperature is above 113F or below -4F, the high temperature or low temperature warning icon on DELTA's screen will light up and flash correspondingly. At the same time the battery management system (BMS) will regulate the input and output of power to protect DELTA.
If you want to charge your DELTA in low
temperature environment (between -20°C – 0°C) please use your DELTA to power an electronic with a voltage over 500W for over 10 minutes to warm up DELTA before charging it.  

After 800 Cycles of use, DELTA's capacity will drop to 80%. However, the lifespan of a battery depending on how it is used, maintained, etc.

Please use and store the device according to the following environment temperatures:
Normal use and storage: -4 to 113°F (-20 to 45°C)
Optimal use and storage: -4 to 77°F (20 to 25°C)

Cold weather use
Cold temperatures (below freezing) can affect the unit's battery capacity due to chemical characteristics of the battery. Keep the power station within the environment temperature range, -4 to 113°F (20 to 45°C) to prolong battery life.

Discharge EF DELTA to 30%, then charge to 85% every 3 month. This can help prolong the battery life and ensure your EF DELTA is ready to recharge the gears at all times. Without any external sources for power supply during storage, EF DELTA has a shelf life of over a year. 

DELTA can be charged by Ecoflow solar panels when the open-circuit voltage is between 10V and 65V. You can connect up to 3 EcoFlow solar panels in series. You can also connect 2 sets of 3 solar panels connected in series in parallel (up to 6 panels). The parallel connection cable is an optional accessory that needs to be purchased separately.

You cannot use DELTA to jumpstart your car, because the current needed for jumpstarting a car is higher than 20An (DELTA's car port can only allow a maximum current of 8An).
DELTA can charge the lead batteries of your car through the car charge cable included in your DELTA parcel.

You can use MC4-XT60 cable to recharge your DELTA. This type of cable come with the box.

DELTA can charge Tesla around 40 minutes. After charging by DELTA you can drive your Tesla for 3-5miles. However, the mileage that can be lasted after one charge by DELTA varies, it is depends on the types of EVs you are driving and the ambient temperatures.

DELTA 1000 and DELTA 1300 are equipped with the same number of battery cells, but battery cells of different energy densities are used.

DELTA's AC ports support pure sine wave. As a result, when you plug your electronics in DELTA, they are well-protected with less generated electrical noise and longer-lasting motors.

DELTA supports an entry-level UPS function. But please perform multiple tests to confirm compatibility before connecting such devices as data servers and workstations with DELTA. EcoFlow will not be responsible for any loss of data or equipment damage caused by customers’ failure in following the instructions.

The solar panels are IP67 rated so they can still function in the rain but the performances of the panels depend on how much sunlight is available. You can rest the solar panels on the car roof, the boat roof and the roof of your house for efficient and convenient solar power (You can purchase EcoFlow's suction cups separately to help attach the panels to flat surfaces).

DELTA is equipped with the EcoFlow patented fast-tracking MPPT controller, which is supported by EcoFlow's unique tracking algorithm. This algorithm helps maximize the solar input under any weather condition. DELTA supports any solar input ranges from 10V to 65V with a maximum allowed current of 10A and a maximum input of 400W. You can chain your solar panels in series or in parallel to maximize the solar input.

Here we listed some similarities and differences between the RIVER Pro and the R600 Pro:
RIVER Pro and R600 Pro have a similar capacity: RIVER Pro: 720Wh vs R600 Pro: 768Wh. Both can be recharged via AC wall outlet, 12V car charge and solar panels and has 10 available outlet options, including 3 x AC output, 2 x USB-A, 1 x USB-A fast charge, 1 x USB-C, 1 x Car cigarette output, 2 x DC5521. Both can be recharged from 0% to 80% in 1 hour and fully recharged 1.6 hours.

RIVER Pro has the advantages in wider discharge temperature range and lighter weight. R600 Pro has the advantages in longer lifecycle and capability to connect an additional unit in parallel via X-link.

RIVER Pro and R600 Pro have their own accessories options. For instance, the RIVER Pro and the R600 Pro do not share the same Extra Battery option: The RIVER Pro can connect to a RIVER Pro Extra Battery but the RIVER Pro Extra Battery does not work with the R600 Pro. Meanwhile the R600 Pro can connect to an EF1500 but the EF1500 does not work with the RIVER Pro.

The RIVER Pro is now selling at EcoFlow Official website, Amazon.com and other authorized EcoFlow dealers. Although the R600 Pro is not selling anymore, we will continue to provide customer support and warranty service for the product.

Detailed Comparison: