This futuristic portable battery kept my home running during an outage, with plenty of power to spare

ZDNET’s key takeaways

• The EcoFlow Delta Pro 3 battery generator is available now for $3,199.
• The Delta Pro 3 provides 4 kW of power output with a 4 kWh capacity and can be used with other units for up to 12 kW output. It also has wheels for easy transport — an important feature for heavy portable batteries.
• The DP3 is very heavy, a factor buyers should consider if they plan to load it in and out of vehicles. 

My home experiences many power outages. Luckily, I’m somewhat used to them since I grew up in a developing country where power loss was a near-daily occurrence. But I’ve already had three or four outages in the first half of 2024, each caused by extreme weather, falling trees, or substation maintenance issues.

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These power issues have made me rely on a good backup system like the Delta Pro Ultra and Smart Home Panel 2. Even controlling every individual circuit and using the bare minimum, a single Delta Pro Ultra can only go so far. With careful management, it’s lasted between 24 and 36 hours in our almost 3,000-square-foot home.

While this isn’t bad, running out to find somewhere to charge the DPU is a hassle. Last time, we opted for an EV charger at a library. The Delta Pro 3 has excelled in this area in our home.

While the DP3 is an entire backup battery capable of keeping a refrigerator running for up to three days, I had a chance to actually test it in a real-world power outage to work as a backup to our backup. 

What happened to knock out the power? A nearby tree fell on some powerlines earlier this month, causing outages in our area, so my husband and I went into full-on crisis mode. While the EcoFlow Delta Pro Ultra knows when severe weather is coming and fully charges itself beforehand, this tree gave into gravity a day after a storm, so the DPU battery was at 82% when the power went out.

Given that our home appears to consume power by simply existing, I began shutting down low-priority circuits on the Smart Home Panel 2 using the EcoFlow app. Thanks to our recent switch to Google Fiber, we kept the ONT and router running so we could keep our internet access on and not miss out on work. 

I also kept our fridge, air conditioner, three ceiling fans, and the microwave running. Of course, I was like a dad stereotype shutting down circuits as soon as someone left the room, but it’s worth keeping the lights on during an outage, especially as you don’t know when the power will return.

By the 12-hour mark into the power outage, our single DPU had depleted to 12%, so it was time to pull out the Delta Pro 3 to get us to the finish line. 

Because I was testing the Delta Pro 3 with a separate test flight app before launch, so I couldn’t efficiently test how it worked with the Smart Home Panel 2 and Delta Pro Ultra during an outage, as the latter are controlled in the generally available EcoFlow app. I decided to test it as a portable battery inside our home instead of alongside the DPU in the garage.

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The Delta Pro 3 is whisper-quiet when running. It’s quieter than a desktop computer’s hum, making it an easy addition to our home. Because it’s a portable battery and not a gas generator, you can bring it inside occupied areas without worrying about toxic fumes like carbon monoxide. 

This battery generator can power high-demand appliances, with both 120V/240V and 4000W options. It features fast charging support and can be used on its own, or in conjunction with solar panels or the EcoFlow Smart Home Panel 2. Of course you can also just use an inlet box or transfer switch. 

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When the DPU battery ran out, we connected the Delta Pro 3 to our optical network terminal (ONT) and router to stay connected to the internet and continue working from home uninterrupted. We also used it to charge our devices, including our laptops, with an extension cord running up to the second floor. 

How did it fare? The power returned about three hours later, and the Delta Pro 3 still had over 50% left in the bank. Not bad at all.

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Aside from this power outage, we’ve tested the Delta Pro 3 as a standalone battery to power a home office setup, keeping consumption between 50W and 120W. The DP3 powered an LCD monitor, a Dell XPS laptop, a phone charger, and a USB-C tablet charger for four days. 

ZDNET’s buying advice

The EcoFlow Delta Pro 3 is an excellent option for anyone looking for a higher-capacity portable battery for camping or as an emergency home backup, as long as you’re willing to pay the price, literally. It’s not a cheap option among portable batteries, priced at $3199, which is about $400 less than the price of a Delta Pro and Dual fuel inverter generator bundle.

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Though priced high, the Delta Pro 3 seamlessly integrates into an EcoFlow home backup system and can expand its capacity to up to 48kWh, with three units and up to two extra batteries each. It also pairs well with the dual-fuel EcoFlow Smart Generator 4000 to maximize oil-to-electric energy efficiency.