EF EcoFlow Delta Pro 3 bundle $3,599 (was $6,298) at Amazon

If you’ve been eyeing an upgrade to your home backup or off-the-grid setup, the EF EcoFlow Delta Pro 3 is enjoying a rare 43% discount at Amazon. The package is reduced to $3,599 from the standard price of $6,298 and includes the Delta Pro 3 itself and an additional 4kWh expansion battery so that you can feast on a total of 8kWh extended out of the box. EcoFlow is also including a bonus portable solar panel on eligible purchases over $2,000, for the ultimate value on first-time solar charging.

Why this rare 43% discount on Delta Pro 3 matters now

High-capacity, whole-home capable battery systems like this one just don’t fall to these depths very often. The headline number — 43% off — is a $2,699 savings on an apparatus meant to keep essential circuits powered through extended outages, cover high-wattage tools at a job site or run an RV without the fumes of a gasoline generator. And with energy resilience fast becoming a household priority, the timing is noteworthy.

According to the U.S. Energy Information Administration, which includes major events in its accounting, the typical American had suffered through about five hours of power interruptions in 2022 — a bit lower than a spike the year before, but still far above pre-2010 norms. Longer, weather-related outages are precisely where 8kWh in the tank goes a long way, especially when it means running refrigeration, communications, medical devices and select HVAC systems.

What you get with the Delta Pro 3 bundle and extras

The pack mates the Delta Pro 3’s 4kWh base module with an identical capacity battery, offering you 8kWh of storage from day one and scalable up to a whopping 48kWh through additional modules. The inverter’s continuous output of up to 4,000W has enough power to run several home essentials simultaneously and is capable of starting many high-draw appliances. The system is 120V and can also support 240V split-phase loads via an EcoFlow accessory or home panel.

EcoFlow leans into practicality in its design: lithium iron phosphate (LFP) cells for long cycle life and thermal stability, and an integrated display and app control, plus a fast 10ms uninterruptible power supply switchover to keep your computer or networking gear operating when the grid goes dark. The company’s X-Quiet technology is designed for nearly inaudible operation — the unit can purr along at about 30 dB on lighter loads, a level that is library-quiet.

Real-world power scenarios for an 8kWh battery system

But to put 8kWh in perspective for daily use: A modern, efficient refrigerator might use between 1 and 2kWh per day; a cable modem/router combo at about 0.1–0.2 kWh; and you add another maybe 0.3–0.5 kWh if your CPAP machine’s active for most of the night. That leaves overhead for lighting, phone and laptop charging, and intermittent loads such as a sump pump or microwave. It can handle more demanding tasks thanks to the 4,000W of inverter power, and if you use the right accessories, it will even run certain 240V circuits like a smaller heat pump or dryer or water heater.

That 4kW is sufficient for the majority of travel-trailer and fifth-wheel installations, powering air conditioners, induction cooking, and electronics with judicious load management that RV owners will appreciate. 4,000W at 240V is about 16.7 amps; 120 volts brings you close to twice that figure, roughly 33 amps. That’s enough muscle for “whole-home lite” coverage with a transfer switch or smart panel that doesn’t provide power to every circuit in the house.

Charging options, UPS capability, and being solar-ready

The Delta Pro 3 is designed for rapid recharging using wall power, vehicle charging and solar. The bonus portable panel on eligible purchases means the power simply is not contained until you plug into a wall — perfect as a backup during outages, or as an off-grid solution. The 10ms UPS mode is kind of impressive; enterprise UPS systems will usually target something in the range of 10 to 20ms to avoid having their sensitive electronics all reboot like a teenager’s computer, so seeing that on a consumer-level backup is pretty nifty.

LFP chemistry is another differentiator. Cycle counts vary by manufacturer and operating conditions, but LFP cells are renowned for thousands of charge cycles before they reach 80% capacity, so a system like this can withstand years of occasional outages or daily stints off the grid with predictable performance.

Quiet, fume-free backup compared with gas generators

Noise and emissions are the areas that battery systems outperform. Most gas generators hum along in the 65 to 75 dB range at standard distances — conversation-drowningly loud. EcoFlow’s relatively low noise profile makes it more appropriate for use inside — or at night — and there is no danger of carbon monoxide poisoning when the power station sits inside while the solar panel stays outside. Even the Consumer Product Safety Commission has repeatedly cautioned about CO incidents related to generators, a risk that battery systems completely mitigate.

Before you check out: essential buying and setup tips

Make sure that the discount and free panel promotion is still available before adding them to your cart; you should be notified of both in your checkout basket. Marketplace pricing can fluctuate based on supply and demand. If you are going to be powering home circuits, have a transfer switch or smart home panel installed by a qualified electrician in order to comply with electrical code and ensure the safety of utility workers. For 240V loads, ensure you have the right EcoFlow accessories and know your amperage limits.

Also consider your energy profile. If you’re riding through long outages as a rule and you want passable off-grid autonomy without the home charging, plan to spend pocket change on some extra batteries down the road. If your needs are less demanding — perhaps you just want to keep a fridge cold, your devices online and a couple of lights on — well, the 8kWh model sits at the ideal size for capacity, portability, and now, pricing.

Bottom line: The EF EcoFlow Delta Pro 3 package gives you some serious backup power, with modern conveniences and the ability to expand its capacity via solar panels; at nearly half off it’s an appealing alternative, in tandem with a gas generator, for homes, RVs and small businesses.