EB3A Solar input not working

My new EB3A does not work with Solar input.
It keeps flashing “Input” on the display, but the app says low PV voltage.

The PV voltage open loop is 22V and its a 120W panel in direct sunlight.

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What 120w solar panel are you using? Does it terminate with mc4 connectors? If so, have you taken a multi-meter to the mc4 leads coming from the solar panel? Then if it terminates with a dc7909 barrel plug, have you taken the readings from that point?

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@thomasdkjensen You can try to upgrade the firmware to solve the problem.

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I would also verify that the connector polarity is correct if the panel is other than a Bluetti panel.

Hi all, a small update.

  1. The panel is a Dokio DSP-100 (100W) with MC4 connectors.

  2. I got it to charge today reached 101W. It seems as it has trouble beginning to charge from plug-in. But at a point, it goes from 0 to 22W, and then it works flawless between 1W and 101W.

  3. When going to FW upgrade in the app, it just tells me the current version, and I am not able to update anywhere, so maybe no new version is available? (I don’t recall the numbers now).

How to update the FW? The app just shows me the current version: ARM 2053.07, DSP 2052.04

SN: EB3A2253000226427

@thomasdkjensen I will contact Bluetti Technician to send the firmware to you. You can try to update it in 24hrs to check if the problem can be solved.

@thomasdkjensen Could you please provide me with the current DSP version so they can push the firmware?

Yes, current DSP Version is v2052,7

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@thomasdkjensen Thank you. You can try to upgrade the firmware.

Thanks, now I got the v2052.10.

I will try again in a few days :+1:

I’m glad to help you. Hope your problem can be solved in this way.

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GOOD NEWS: This well-known problem can be solved easily, as I found out.
The MPPT converter has an initialization problem when the current delivery of the solar panel is a bit too low. It tries to initialize again and again, causing this famous flashing of the “INPUT” sign.

What happens at start-up: When the DC7909 jack is plugged in, the converter sees a sufficient voltage (e.g. 14V) to wake up and switch the EB3A display on. After about 1 sec, it starts drawing current from the panel, causing a voltage drop. Under low light conditions, voltage will immediately fall below a critical limit. The MPPT will “give up” now, stopping to draw current. The voltage goes up again, the MPPT will see a good reason to start … same procedure again.

The simple solution: Adding a 2200uF electrolytic capacitor to the solar cable will “harden” the panel voltage for the short moment when the MPPT tries to start. The MPPT will initialize and keep running, even with very low solar input (down to 3W). In my example, I measured ~11V and ~0,3A on the DC7909 input. You need to be aware however that the minimum power consumption of the EB3A is ~4W when on only display is on, while DC and AC outputs are off. You also need to know that input power <10W will be displayed as INPUT 000 while the Bluetti app will show the real value.

Here is the simple adapter cable I created for my panel (which uses an EC3 intermediate connector):


Today I tested and it started up @12W. I think that’s good enough. So for me, the problem is solved.

Interesting solution (with the capacitor)… Does it work even when the capacitor is fully discharged at the time of plugging in the panel? How about leaving the panel plugged in overnight and thus starting at very low voltage at dawn?

This also works when the cap is fully discharged when the panel is plugged in - even if power is below 10W. I do not know yet if the „over night scenario“ is going to work …

The cap will charge very quickly (<1 seconds) when the panel is plugged in before you plug into the EB3A. At 2200uF at 14V, only around 0.2J is stored in the capacitor, so even at 1W power it will charge in 0.2s.

As long as you connect the panel before connecting it into the EB3A, the cap will be charged.

Excellent solution. I’ve also seen this issue with one of my Jackery (E1500 V1), where under certain light condition, the MPPT would try to start over and over again. This may be a fix for that as well.

Fun fact, when input is ~50W from solar and there is a consumption of 42W (Small fridge), the battery is draining slowly. Is this due to the internal inverter not being calculated into the power consumption?

Well after 2 hours of running a small fridge (~40W drain) it shut down with “Overload indicator” active

That’s a bit of a turn down. What to do now?

And now “Overload” again after 1 hour more at 72% battery.

It should be able to handle a small 40liter fridge. I saw a guy online powering a big Samsung fridge with freezer and water cooler.