EcoFlow’s DELTA Pro Ultra arrives as two heavy modules, an inverter and a 6,144Wh battery, and getting it running takes about five steps: stack it, cable it, power it on, link the EcoFlow app and set a few energy limits. EcoFlow’s user manual (models EFYJ751-PCS-US and EFYJ751-BP) lays out each step, from locking the battery cable with a flathead screwdriver to choosing a charge limit between 50% and 100%. This guide follows the manual in order and explains which settings matter most for home backup, solar and everyday use.
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I haven’t set up a DELTA Pro Ultra myself. Every step and default below comes from EcoFlow’s DELTA Pro Ultra user manual and its Smart Home Panel 2 owner manual, and I’ve quoted defaults exactly as EcoFlow lists them. You can find the system on EcoFlow’s website. For the full spec rundown, see our EcoFlow DELTA Pro Ultra review.
It is also sold on Amazon: EcoFlow DELTA Pro Ultra (inverter + 6,144Wh battery) on Amazon.
Safety note: Connecting any battery system to your home’s wiring, a transfer switch, a Smart Home Panel 2 or a rooftop solar array is electrician work. EcoFlow’s manual says installation into a home backup system should be done by a licensed electrician. See our electrical safety basics for DIY solar.
What’s in the box
The inverter and battery ship separately. According to EcoFlow, the inverter box includes:
- DELTA Pro Ultra inverter
- Portable stand, four supporting legs, four side-mount casters and four M6x20 screws
- Disassembly and assembly tool (for the high-PV solar connectors)
- Solar to low-PV port charging cable
- AC charging cable (C20)
Each battery box includes the battery and one battery connection cable. EcoFlow notes the inverter must be used with at least one battery.
Key specs to know before you start
| Item | EcoFlow spec |
|---|---|
| Battery | 6,144Wh LFP per battery (102.4V, 60A); 80%+ health after 3,500 cycles |
| Expansion | Up to 5 batteries per inverter; up to 3 inverters and 15 batteries (about 90kWh) with Smart Home Panel 2 |
| AC output | 7,200W pure sine, 120/240V, 60Hz |
| UPS | Online UPS 0ms on designated outlets; backup UPS under 20ms on others |
| High-PV input | 80–450V, 15A max, 4,000W max |
| Low-PV input | 30–150V, 15A max, 1,600W max |
| AC charging input | 100–120V 15A or 200–240V 12.5A |
| Power input/output port | 30A at 120V or 240V (generator, EV charger, Smart Home Panel 2) |
| Noise | Under 30dB in most scenarios |
| Ambient temperature | −4°F to 113°F (battery) |
| Rating | IP54 when not in use |
Step 1: Pick a spot and mount the stack
EcoFlow gives four mounting options:
| Option | Limit (per EcoFlow) | Best for |
|---|---|---|
| Portable stand with casters | Up to 5 batteries; lock caster brakes above 3 | Garage or utility room |
| Two sets stacked | Top set uses legs, not casters; up to 2 batteries per inverter | Saving floor space |
| Shelf, separate locations | Uses a 0.75m battery connection cable | Tight closets |
| Trolley | One inverter and one battery only | Moving between home, RV and job site |
For the portable stand, install the stand first, then the battery, then the inverter on top. Line up the battery ports on the same side and seat each module in its grooves. A few placement rules from the manual are worth following:
- Use a hard, flat surface. EcoFlow warns against dirt, sand or slopes.
- Leave about 5cm (2 inches) between the stack and the wall for heat dissipation, and never block the fans.
- With three or more batteries, lock the casters and fit EcoFlow’s fixing metal tabs to the battery under the inverter.
- Get a second person. EcoFlow says the modules are heavy enough that two people should carry them.
Step 2: Connect and lock the battery cables
Open the protective covers and connect the battery connection cable between the inverter and battery. With multiple batteries, follow the cable sequence in the manual’s diagram. EcoFlow recommends locking each cable with a flathead screwdriver so it can’t be pulled out by accident, and unlocking it before removal.
Step 3: Power on and learn the buttons
Long-press the main power button on the inverter or any battery for one second. Press and hold for two to three seconds to turn it off. A single press turns the screen on or off without shutting down the system. If the unit is off, plugging it into a wall outlet turns it on automatically.
| Button or control | What it does |
|---|---|
| Main power button | 1s to power on; 2–3s to power off; single press for screen |
| AC power button | Turns AC outlets on or off; hold 10s to switch AC output frequency |
| DC power button | Turns the 12V DC outputs on or off |
| AC charging speed switch | Left for peak charging speed; right to return to the default (and let the app control it) |
| PV switch | Enables or disables solar charging |
Which outlet does what
This matters for UPS. EcoFlow labels each AC socket by UPS type:
- Online UPS (0ms): the 120V 20A sockets marked online UPS and the 120V 30A online UPS socket. Use these for computers and network gear that can’t tolerate any gap.
- Backup UPS (under 20ms): the 120V 20A sockets marked backup UPS and the 120V/240V 30A socket. Fine for fridges, lights and most appliances.
Step 4: Connect the EcoFlow app
- Download the EcoFlow app from the App Store or Google Play and create an account.
- The app usually prompts you to add the device. If not, tap “Add” or the plus sign in the top right and select the DELTA Pro Ultra when it appears.
- Connect over Bluetooth first. Then tap the icon next to Bluetooth and enter your Wi-Fi password to switch to IoT mode, so you can control it away from home.
- Optional: insert EcoFlow’s 4G dongle (sold separately) in the 4G port for a cellular connection to EcoFlow’s web portal.
- Rename the unit under General settings; it defaults to its serial number. You can also share control with another person by email.
Step 5: The settings that matter
Timeouts
The app lists four timeouts with these defaults:
| Timeout | Default | Suggested change for home backup |
|---|---|---|
| Unit | 24 hours | Set to never if it sits on standby for outages |
| Screen | 5 minutes | Leave as is |
| AC | 12 hours | Set to never if a fridge or sump pump is plugged in |
| 12V DC | 12 hours | Set to never if you run 12V loads overnight |
The suggestions in the right-hand column are mine, not EcoFlow’s. The idea is simple: a timeout that switches off AC during a quiet stretch could leave a fridge without power.
Charge and discharge levels
Under Energy management, set a charge limit between 50% and 100% and a discharge limit between 0% and 30%. The unit stops at those levels, and an icon shows on the screen. For outage backup, a 100% charge limit gives you all the stored energy. A lower limit only makes sense if you deliberately want headroom, for example to soak up solar during the day, and it means less energy in an outage. EcoFlow notes the battery will automatically charge to 100% for calibration if it hasn’t reached full after a month or 30 cycles, then go back to your limit.
Backup reserve
The backup reserve sets how much energy is held back for outages. EcoFlow’s manual explains that above the reserve, the DELTA Pro Ultra runs on solar and the AC input is disabled; below it, AC charging starts. A higher reserve gives more outage protection. A lower one lets you use more of your solar.
AC charging speed
Under Input settings, you can set the charging speed of both the AC charging input and the power input/output port. EcoFlow notes that for app control of AC charging, the physical AC charging speed switch must be flicked to the right. If you’re charging from a generator, set the speed below what your generator can supply.
Timers
Automation lets you set times for AC charging, AC discharging and DC discharging. A common use is charging from the grid overnight during off-peak hours.
Battery preconditioning
In Battery settings, turn on “battery preconditioning” to let the battery self-heat. EcoFlow’s manual says charging heating kicks in below 32°F, needs at least 250W of charging input, and stops once the battery’s internal temperature passes 50°F. If you keep the system in an unheated garage, leave this on.
Charging options at a glance
| Source | Port | Notes from the manual |
|---|---|---|
| Wall outlet | AC charging input | Keep the AC power button off when charging from a high-voltage outlet |
| Generator | Power input/output port or AC charging input | Generator must be rated higher than the charging power |
| EV charger | Power input/output port via EcoFlow’s EV adapter | Connect the adapter, then turn on the main power |
| Solar, high voltage | High-PV input | 80–450V, 15A max, 4,000W |
| Solar, low voltage | Low-PV input | 30–150V, 15A max, 1,600W |
When both the AC charging input and the power input/output port are connected, the manual says the power input/output port takes priority and AC charging won’t run. For solar, always keep the PV switch off while you connect panels, then switch it on. EcoFlow also notes that rooftop arrays connected to the unit need rapid shutdown under the NEC and should be installed by a qualified electrician.
Worked example (estimate): four 400W panels with a 37V open-circuit voltage wired in series produce about 148V, which fits the low-PV range (30–150V) but leaves almost no margin on a cold morning, when panel voltage rises. Wiring them to the high-PV input (80–450V) is the safer choice. Always check your panels’ cold-weather Voc against the limit.
Adding Smart Home Panel 2
For whole-home backup, EcoFlow’s Smart Home Panel 2 connects up to three DELTA Pro Ultra sets. After your electrician installs it, the SHP2 owner manual says you connect the panel to the DELTA Pro Ultra, lock the cable, power on the unit and short-press the matching AC1, AC2 or AC3 button in the battery connection box. In the app, commissioning asks for your grid voltage and frequency, main breaker size, each circuit’s current, and whether circuits are split-phase. SHP2 then offers self-powered, scheduled and time-of-use operating modes, with a default backup reserve of 50%. Read more in SPAN Panel vs EcoFlow Smart Home Panel 2, transfer switch vs interlock kit and our critical loads panel guide.
Maintenance checklist
EcoFlow recommends checking the following every three months:
- Vents are free of dust and obstructions
- Exterior is clean; wipe with a dry, soft cloth, no chemicals
- No damage, deformation or unusual sound
- All cables are intact and secure
For long storage, EcoFlow says to cycle the battery every three months (discharge to 0%, fully recharge, then discharge to 60%), and notes the warranty won’t cover a battery left uncharged and unused for more than six months.
FAQ
Can I use the DELTA Pro Ultra without Smart Home Panel 2?
Yes. It works as a large standalone power station through its own outlets. SHP2 or a transfer switch is needed to back up home circuits.
How many batteries can one inverter run?
Up to five, for about 30kWh. With three inverters on SHP2, EcoFlow lists up to 15 batteries.
Which outlets give 0ms switchover?
The sockets EcoFlow labels “Online UPS”: the online-UPS 120V 20A sockets and the 120V 30A socket. The manual’s port diagram shows which is which.
Why won’t my DELTA Pro Ultra charge from the wall?
Check whether the power input/output port is also connected, since it takes priority. Also check your charge limit and backup reserve settings in the app.
Does it need to be grounded?
EcoFlow says that when it’s connected to solar and placed inside a building, it should be grounded using the ground screw. Consult an electrician for local code.
How do I reset the Bluetooth connection?
With the unit turned off, press and hold the main power button. EcoFlow’s manual lists both 5 and 10 seconds in different sections, so hold it for the full 10 seconds.
Bottom line
Setting up a DELTA Pro Ultra is mostly about doing things in order: mount the stack on a flat surface, lock the cables, link the app over Bluetooth and Wi-Fi, then set timeouts, charge limits and the backup reserve to match how you’ll use it. Leave home wiring and rooftop solar to an electrician. If you’re weighing a generator alongside it, our guide to pairing a home backup battery with a generator covers the options.