EcoFlow RIVER 2 and DELTA 2 Not Charging: Fix 0W Input

The EcoFlow RIVER 2 and DELTA 2 are built to be plug-and-play — connect a cable, watch the input watts climb, and the unit charges. When you plug in and the input stays at 0W, the screen stays dim, and nothing happens, it is a jarring moment. The instinct is to assume a hardware fault. In most cases it is not. As powerstationlab.com documented in their 2026 troubleshooting guide: “Because EcoFlow units (like the RIVER 2 and DELTA 2) are highly computerized, they have aggressive safety mechanisms. If the system detects heat, a surge, or a software glitch, it locks the charging port to prevent a fire.” (powerstationlab.com) The diagnostic sequence below covers every cause of a 0W reading in order of likelihood, so you can resolve the problem in minutes rather than hours.

This guide is written specifically for RIVER 2, RIVER 2 Pro, RIVER 2 Max, DELTA 2, and DELTA 2 Max owners. The DELTA 3 has a different solar input circuit and its own zero-watt troubleshooting steps, covered in our DELTA 3 solar input guide. The DELTA Pro solar input spec differs from both; the steps here apply where noted but the DELTA Pro section of the EcoFlow app has additional input settings not present on the DELTA 2.

Check 1: The AC charging speed slider in the app

Before assuming anything is broken, open the EcoFlow app and navigate to your device’s Settings. Look for AC Charging Speed or AC Input Power — the label varies slightly between app versions. You will see a slider that sets the maximum watts the unit draws from the wall. On the RIVER 2 this ranges from 200W to 900W. On the RIVER 2 Pro it goes up to 1440W. On the DELTA 2 the range is 200W–1800W. If the slider is sitting at its minimum position — 200W on most models, or occasionally 0W on some firmware versions — the unit will draw so little current that the dashboard displays 0W even though it is technically connected and charging at a near-invisible rate.

This slider position is the single most frequently overlooked cause of a 0W AC reading, and it explains why the problem appears suddenly after a firmware update (the update resets the slider to minimum as part of its settings wipe, which we cover in our firmware settings reset guide) or after a friend or family member adjusted the unit’s settings. Drag the slider to a sensible charging level — 600W is a good quiet-charge setting on the DELTA 2, full 1440W gets you the RIVER 2 Pro’s rated 80-minute charge time — wait five seconds for the app to send the change, and watch the input reading on the dashboard. If the watts jump to the expected level, you are done.

Check 2: Solar cable polarity and voltage limits

If the 0W reading appears when charging from solar panels rather than AC, the first thing to verify is the XT60 cable polarity. The RIVER 2 and DELTA 2 both use an XT60 solar input connector. Third-party MC4-to-XT60 adapter cables, especially lower-cost imports, are sometimes wired with the positive and negative conductors swapped relative to the EcoFlow XT60 socket. With reversed polarity, the MPPT controller sees a negative voltage on the positive terminal, outputs 0W, and does not throw a visible error code. To check polarity, look at the XT60 socket on the unit — the positive terminal is marked with a + sign or is the slightly wider blade on some connectors. Trace your cable back to the MC4 connectors and verify the positive wire (typically marked with a ridge or a + in the sheathing) connects to the positive terminal. If they are swapped, the cable is faulty and needs to be replaced.

Once polarity is confirmed, check the open-circuit voltage (Voc) of your panel array against the unit’s input limits. The RIVER 2 accepts solar input from 11V to 30V Voc — a relatively low ceiling that rules out most series-wired panel combinations. Two 24V panels in series produce 48V Voc, which the RIVER 2 will reject entirely. The RIVER 2 Pro and RIVER 2 Max share this 30V ceiling. The DELTA 2 is more permissive at 11–60V Voc, but two standard 12V panels in series producing a 44V Voc are within range. Use a multimeter on your MC4 connectors in full sun (before connecting to the unit) to confirm the open-circuit voltage is within the spec. For a detailed calculation of charge time given your panel wattage and the DELTA 2’s 1024Wh capacity, see our solar charge time calculation guide.

Check 3: Hard power-cycle to clear a BMS lock

If AC charging shows 0W and the app slider is set correctly, the BMS has likely engaged a protective lock. This happens more frequently than most owners expect. Common triggers include: a voltage spike from a generator that the unit was connected to during startup, a charging session in ambient temperatures above 40°C that caused the BMS to detect thermal stress, or a software state that was not cleared after the last shutdown. The BMS lock is not a permanent state — it clears on a full power-cycle — but simply turning the unit off and on with the power button is not enough to clear it because that is a soft shutdown that does not fully reset the BMS state machine.

The correct BMS reset procedure: disconnect every cable from the unit — AC input, solar input, AC output loads, DC output loads, USB cables. Everything off. Press and hold the main power button for 10 seconds. On most RIVER 2 and DELTA 2 units, the display will flash briefly and then shut off. If the display does not respond, hold for 15 seconds. Once dark, wait 30 seconds without touching anything. Then press the power button once to restart normally. When the unit boots, reconnect the AC cable. In the large majority of cases where a BMS lock was the cause, the input watts will appear immediately on the dashboard. If you were seeing 0W from solar but AC works correctly after this reset, the BMS lock was triggered by a solar-input anomaly — check the panel voltage and current before reconnecting.

Check 4: BMS recalibration if power-cycle does not fix it

If the power-cycle clears the 0W reading but the unit charges slowly, stops before your set charge limit, or the state-of-charge percentage seems inaccurate after charging, the BMS may need recalibration. This is a separate issue from the BMS lock — it is drift in the BMS’s estimation of the battery’s true capacity rather than a protective lockout. BMS drift is most common on units that have been frequently used in partial charge cycles (charged from 40% to 80% repeatedly without ever fully cycling) or on units that have not had their firmware updated in more than six months. The recalibration procedure is covered in depth in our BMS recalibration guide, but the short version is: discharge the unit to 0% under normal load, allow it to shut off naturally, then charge from 0% to 100% in a single session without interruption. One full cycle like this resets the BMS’s capacity baseline.

The signs that distinguish a BMS lock (sudden 0W, nothing was wrong before) from BMS drift (gradual accuracy loss, unit still charges but percentage readings are off): a BMS lock typically appears without warning after an event (surge, heat, software glitch) and is resolved by the power-cycle described above. BMS drift develops gradually over weeks or months and is characterised by the unit reaching “100%” earlier than expected, the estimated runtime being significantly lower than usual, or the unit shutting off at 5% when it still has meaningful charge remaining. If you are seeing the gradual pattern, skip to the recalibration guide. If the 0W problem appeared suddenly, the power-cycle is almost always the right first step.

Check 5: Firmware update as a last resort before support

A smaller number of 0W charging failures on the DELTA 2 and RIVER 2 are caused by firmware bugs — specifically, bugs in older firmware that cause the BMS to misread the charger connection state after the unit has been in standby for an extended period. EcoFlow has released patches for these bugs in subsequent firmware versions. If you have completed the AC slider check, polarity verification, and BMS power-cycle without success, checking for a firmware update is a reasonable next step. Open the EcoFlow app, navigate to your device’s Settings, and tap About or Firmware Update. If a newer version is available, apply it — the update takes 5–10 minutes and the unit will reboot automatically when complete.

After the firmware update, recheck the AC charging speed slider (it will have reset to default as described in the firmware settings reset guide) and attempt charging again. If the 0W reading persists after a firmware update and a subsequent power-cycle, the fault is most likely hardware — either the AC input circuitry or the charge port. Contact EcoFlow support with the serial number visible on the bottom of the unit and a description of the steps you have already taken; this will skip the standard troubleshooting script and get you to a replacement or repair evaluation faster. For RIVER 2 units within two years of purchase, EcoFlow’s standard warranty covers charging port failures that are not the result of physical damage.