EB3A won't start solar charging under 18W / PV low voltage

Hi,
I already have an EB70 an like it very much (except for the missing SOC percentage).

I received an EB3A recently. It’s a european version (230V) and has got the latest firmware, which in Europe is
ARM v2053,07
DSP v2052,04

Short Version: As long as the solar panels deliver less than ca. 18W, it won’t start charging at all. The “Input” sign in the display blinks and the app says “PV low voltage error”.

The EB70 has no problem at all to start charging in this situation.

The open circuit voltage in this case is usually about 22,4 V, so it should be plenty enough.

One the EB3A has started to charge, it will continue to do so even when the power drops to 1W.
If I then unplug the panel and plug it back in, the error appears again and I have to wait till the power exceeds ca. 18W.

Conclusion: My EB3A has no problem to charge via solar, but it has problems to start charging.
My EB70 start charging even when there is only 1W available.

In real life this can mean that on a cloudy day the EB3A does never start to charge but instead uses up about 2% battery per hour and so loses power over the day instead of collecting e.g. 16 watts per hour.

This may seem like am minor problem because <18W is not much, but I guess that most of the small power stations will not be attached to huge solar arrays.
With this error the EB3A can’t just be left alone gathering watt hours…

Is this a known problem with the EB3A an can/will this be fixed in firmware? Or is my unit faulty?

By the way: I have charged and discharged the device twice and once it charges it works fine. AC charging also works fine.

I wish it would charge just as the EB70, then it would be a great litte device with only minor flaws (funny fan noises, noch charge under 10W displayed etc.).

Thanks to Bluetti and the community (hopefully) for answers.

Cheers from Germany,

Harry

1 Like

Hi @Riesling-Harry , sorry for inconvenience caused.
This should input wattage too low and not show up when charging (it is actually charging).
If you confirm that the EB3A does not have any charging input when performing PV charging, you can send a video and contact our support department via sale-eu@bluettipower.com for a more specific solution. Thank you very much for your cooperation

It should charge at 12 volts up to 28 volts. Disconnect the solar panel and Verify what your voltage is with a meter to the solar panel. When on the low end, it can take awhile for the mppt to lock in.

With such a small window, it is a challenge to overpanel, so that you get the voltage needed early in the morning and later in the evening. The victron starts at 5 vdc. A bit easier to match up. But it not portable.

Hi Admin, hi aly,

thanks for answering. As I said, the OC voltage was around 22V, I’ve tried dozens of times with the same result:
The EB3A has a problem to start charging when under ca. 18W, but once i has started, it will continue to charge even when there is only 1W left (or even 0W).

So I think that the hardware is ok, it just needs a firmware update to change the starting behaviour.

I have put a video on youtube to illustrate the problem and the difference to the EB70:

Yours,

Harry

I have the same problem. I get 18.3 volts and still get input flashing. So I measured the current and found out that it must be > 1 amp before it stops flashing.

Hey hey,

that is very useful information because it (hopefully) means that my EB3A is not broken.

1A at about 18-19V working voltage corresponds well with my 18W threshold.

Let’s hope for a firmware update.