EcoFlow Delta 3 Max Solar Input (100W Solar Panel Test)

How much of a difference can a single 100-watt solar panel make on the EcoFlow DELTA 3 Max? Can it keep up with the electricity you’re using, or will the battery still drain? I ran that test with a STAR Cleanedge 100W panel while powering tool battery chargers, lights, and a space heater — and filmed the whole run.

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Testing note: Every watt figure below is from my own readings on this 100W run. I’m planning follow-up videos with a 200W panel and a two-220W panel setup; those numbers are not in this post yet.

Products in This Test

👉 EcoFlow DELTA 3 Max — 2,048Wh LFP battery, 2,400W inverter, up to 500W solar input

👉 STAR Cleanedge 100W solar panel — frameless Cleanedge design, 100W, high-efficiency cells

The Setup: STAR 100W Panel + Delta 3 Max

The Delta 3 Max is a 2,048Wh LiFePO4 power station with a 2,400W inverter. For this video I wanted a technical look at solar offset — how much of a live load a small panel can cancel out — not just how long the station takes to recharge with the panel alone.

I connected the STAR Cleanedge 100W panel to the Delta 3 Max’s solar input and watched the input watts on the station while I plugged loads in one after another. Earlier in the day the panel was putting out about 70–80W. As the sun started going down, that settled around 48–54W. For the load math in this post I used a steady 50W of solar — a fair late-afternoon number from this exact run.

The STAR Cleanedge panel uses a frameless design meant to shed dust and water, with high-efficiency cells. It’s a simple one-panel setup: aim it at the sun, plug into the XT60i port with an MC4-to-XT60i cable, and read the input on the display or in the EcoFlow app.

Test 1: Tool Battery Chargers — Breaking Even

First I plugged in a few cordless-tool battery chargers. Together they drew about 49W. With the panel producing about 50W, the station was pretty much breaking even — solar covered the chargers, and the battery wasn’t really gaining or losing much.

That’s the sweet spot for a small panel: when your load sits near what the panel is making, you can keep charging tools without dipping into the pack. Earlier at 70–80W, that same ~49W charger load would have left a little leftover solar going into the battery.

Test 2: Add Lights — Solar Still Covers Most

Next I plugged in some lights. Total consumption rose to about 63W. With ~50W coming from the panel, solar still covered most of that draw. The battery only had to supply the difference — roughly 13W.

At that level you’re barely touching the 2,048Wh pack. Over an hour you’d pull only about 13Wh from the battery while the panel did the rest. For lights, chargers, routers, and other small devices, a 100W panel on the Delta 3 Max can offset a meaningful share of the electricity you’re using.

Test 3: Space Heater — When 100W Can’t Keep Up

Then I plugged in a space heater with the chargers and lights still connected. On the heater’s lower setting, total consumption jumped to around 1,000W. On high, it reached about 1,500W for all four devices together.

With only ~50W coming from the solar panel, the battery had to supply the rest — about 950W on low and about 1,450W on high. That’s the clear limit of a 100W panel: it helps small loads a lot, but a heater (or any high-draw appliance) still drains the pack hard.

At ~1,450W of net battery drain, a full 2,048Wh Delta 3 Max lasts about 1 hour 25 minutes:

2,048Wh ÷ 1,450W ≈ 1.41 hours (about 1 hour 25 minutes).

That runtime assumes you start from a full charge and hold that load. Real runtime can land a bit lower once you factor in inverter losses and the last stretch of the battery curve, but the 1h25m figure matches the power readings from this test.

100W Offset Summary

Load	Total watts	Solar input	Battery net
Tool battery chargers	~49W	~50W	~0W (break-even)
Chargers + lights	~63W	~50W	~13W from battery
+ space heater (low)	~1,000W	~50W	~950W from battery
+ space heater (high)	~1,500W	~50W	~1,450W from battery

The pattern is simple. Around 50W of solar, tool chargers break even. Lights still leave most of the work to the panel. A space heater flips the math: the panel becomes a small credit against a large battery draw.

Recharging the Delta 3 Max With Only This 100W Panel

What if I disconnected every load and used this single 100W panel just to recharge the EcoFlow? Here in Southern California, a 100W panel can produce roughly 300–500Wh on a good sunny day, depending on season, tilt, and how often you re-aim it.

Filling the full 2,048Wh battery from empty would take about 5–7 good sunny days (2,048 ÷ 500 ≈ 4.1 days on the high end of production; 2,048 ÷ 300 ≈ 6.8 days on the low end). That’s a slow top-up if you rely on one small panel alone — useful for maintenance charging or offsetting light loads, not for a same-day full refill.

Room to Grow: Up to 500W of Solar

The Delta 3 Max accepts up to 500W of solar through one XT60i port, with an 11–60V operating range (keep total panel Voc at or below 60V). So instead of this one 100W panel, you can connect more capacity when you need faster charging.

Two 220W panels, for example, can put out enough on a good sunny day to recharge most of the battery in one day — a big step up from the 5–7 day pace of a single 100W panel. I’m planning follow-up tests with a 200W panel and a two-220W panel setup so we can put measured full-day numbers next to this 100W run.

That flexibility is what I like about the Delta 3 Max for solar. Start with a small panel for light offset, then expand toward the 500W input when you want home-backup top-ups, RV use, or off-grid days with heavier loads.

What This 100W Test Means for Real Use

• Small loads: tool chargers, LED lights, phones, laptops, and similar gear can be largely or fully offset by a 100W panel when the sun is decent.
• Medium loads: a few dozen watts above the panel’s output still only nibble at the battery; solar does most of the work.
• High loads: heaters, high-power cooking, and other 1,000W+ devices will drain the pack quickly; treat the 100W panel as a small assist, not a match for the load.
• Recharge-only days: expect hundreds of watt-hours per sunny day from one 100W panel — helpful, but plan on multiple sunny days for a full refill.

If your goal is camping with a fridge and lights, a 100W panel can stretch the Delta 3 Max further than solar-free use. If your goal is running a heater through an evening outage, you’ll want more panel capacity — and the station’s 500W solar ceiling gives you room to add it.

Watch the Full Test

The full walkthrough is in the video at the top: EcoFlow DELTA 3 Max Solar Input (Testing a 100W Star Solar Panel) (3:03).

Grab the DELTA 3 Max on Amazon and the STAR Cleanedge 100W on Amazon if you want the same setup. I’ll update this series when the 200W and two-220W tests are filmed.

FAQ: Delta 3 Max With a 100W Solar Panel

How much solar did the 100W panel actually produce in this test?

About 70–80W earlier in the day, then about 48–54W as the sun went down. I used 50W as the steady number for the load math.

Can a 100W panel keep the Delta 3 Max from draining?

Yes for small loads near that output. My tool chargers at ~49W were basically break-even at ~50W of solar. Lights at ~63W still left solar covering most of the draw. A space heater at ~1,000–1,500W drains the battery quickly even with the panel connected.

How long would the battery last with the heater on high?

At about 1,450W of net battery use, a full 2,048Wh pack lasts about 1 hour 25 minutes (2,048 ÷ 1,450 ≈ 1.41 hours).

How long to recharge the Delta 3 Max with only a 100W panel?

In Southern California, plan on roughly 300–500Wh per good sunny day, or about 5–7 sunny days to refill 2,048Wh from empty.

What is the Delta 3 Max max solar input?

500W through one XT60i port, with an 11–60V operating range. Two 220W panels can recharge most of the battery in a good sunny day — and I’ll cover measured results in upcoming videos.

Related: EcoFlow Delta 3 Max review · Delta 3 Max charging time · Delta 3 Max space heater test