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

Product Discussion BLUETTI EB Series
1

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

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2

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

3

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.

4

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

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5

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.

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6

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.

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7

Just FYI, I have the “blinking input” 0w solar input, also. When it begins reaching 50 watts, it starts charging, properly via solar.

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8

Same issue here when I was using an extension cable for the solar

9

Bluetti tech specs for the EB3A says 12 to 28 volts. I tested that spec with my variable power supply. 12 volts works fine, it does not have to be 18+ volts. The problem is not the voltage, it is the current. If the current is less than 1 amp, the EB3A will not accept the voltage. It must be > 1amp. It is a bad design of a MPPT controller. Today with cloudy skies and 100 watt solar panel, I got 18.3 volts and .67 amps = 12.26 watts but my EB3A said 000 and the input was flashing.
Bluetti needs to fix this design problem !!!

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10

As gathering solar energy is the main purpose for my power stations, I sent back the EB3A and bought an EB55 as a second device. This behaves exactly like the EB70. I would really like to know if nobody at Bluetti tested the EB3A under various conditions.
I don’t think many EB3As will be connected to a huge solar array that always delivers lots of power.

Really a pity, because otherwise the EB3A would have been exactly what I wanted.

11

I just picked up a UK model EB3A and love it… well I did until I purchased a 100W solar panel expecting to use it in Scotland. My aim was to keep this topped up off grid and power a low wattage heater occasionally.

Sadly I’ve also found out the hard way that the Bluetti MPPT will happily just discharge your entire pack rather than charging, pretty poor design.

This has to be fixed with a simple firmware update surely? C’Mon Bluetti lets see some positive progress on this. There is literally hundreds of posts over various sites and now more increasing disgruntled youtube videos highlighting this pretty major flaw of the EB3A Charge controller.

12

Same behavior here - „low“ input voltage/current discharges the Unit. I‘m Form Germany and we are still stuck with firmware v2053.07 (ARM) and v2052.07 (DSP). I‘ve heared there is an update available, but only for US units…?

13

Same again here, had the EB3A for a while but jusr got a 130W panel thinking I could make the most of having a solar power station.

PV Low Voltage alarm.

Hopefully Bluetti can sort with FW, for now I’ll get an DC8 Y cable and kickstart the charge with a 12V PSU

14

Same thing here:

15

Just for your information: The underlying problem can be solved by a simple external capacitor in the solar cable - instead of waiting for new FW versions :slight_smile:
The details are described at the end of this thread:
EB3A Solar input not working

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16

Same problem here. I’ve been posting this problem all every YouTube channel that does reviews on the Bluetti EB3a. I will continue to do so until this problem is fixed.

17

October 2023, the EB3A PH version (220V) still has the same problem. After backreading, I realize that the EB3A is severely and permanently crippled this way. You must babysit the PV charging, plug the PV cable only when there is enough sun > 18 watts, and unplug it before it drops < 18 watts, or otherwise suffer slow drain. As part of a solar setup, it’s a dealbreaker. If you just need a fancy solar powerbank you can fastcharge when empty, use whenever, then it’s great. I am not expecting Bluetti will acknowledge or fix this problem. If I had known this limitation before, I would still have purchased the EB3A for its other qualities (turbo charging, PD, UPS). It’s just another thing I have to deal with, together with making sure the AC and DC outputs are switched off when there’s no load, which similarly drains battery. But I would have liked to have been informed of this limitation beforehand and avoided all this. Any future purchase of this brand will just need to be done with a lot more thought and research than what I put into this purchase of the EB3A.

1 Like
18

Same issue. I have my EB3A by my bed, when I wake up in morning I just plug in the connector to solar panels and at night I unplug. Not my fave thing, but not terrible either.

My charging starts between 7:30-8am.
I wish there were either a fix, or some kind of adaptor with a timer I could put between it.

19

Bluetti EB3A
ARM: v2053.07
DSP: v2052.09

I just test my new EB3A with a 30W Modul under bad light conditions the last days and get the same problem: Just a blinking 0000Input if the Solarmodul is under 11W!
BUT i noticed (with this actual never upgraded firmware DSP v2052.09), that IF the MPTT gets >11-18W it starts to load and shows the right Watt in the app (and not on Display <10W). I am just testing now, but it seems that if it just once started loaded, it stops to blink under 10W and is charging.

So i think it’s not a bug - it’s a feature!? ;)

Maybe some other powerstations or diy projects are able to load (and showing this) if there is less power, but this box needs >11W to start and i think this is something i can deal with it.
Makes sense, because the MPTT and other stuff needs > 4W and if somebody just loading some things, while charging the bluetti over solar it needs maybe some more reserves!?
And it would be a lie than, if the display showing input, but in fact it is NOT charging, like you can find in this thread !

So it’s just the specification of this special box and i think no firmware update could fix this, because than it would be done in the past, because this “problem” is well known since month.

Short term: The bluetti EB3A needs enough power to start and load.

And this great “cap-hack” is just to trigger the mptt under bad light conditions (<11-18W), stabilizing te signal and helping loading all between 4-11W!

Other Option is a bigger solarmodul with more watts and/or a more lightly place.

For me, i can’t understand, why people in forum (e.g.influencer is planing to send everytime critics-video since the “bug” is gone,…) and on Youtube describing this really hysterical as a “NOGO” - showing the low-voltage-mptt-problem in 2 videos for example with te solarpanel behind a window in dark rooms??
And making bad promotion about this product!??

Hey, i don’t want to “kiss the ass” from bluetti support - but i like it more intelligent and constructive, like this great thread with a solution.

i made the “cap-hack” too with 2x1000uF/40V Caps to stabilize my 30W modul! And it seems to work under really bad conditions.
So i can charge everything between 4-11W (~7W) if there are really bad light conditions.
And with good light and enough power over 11W my bluetti box starts to load.

But in fact i have to wait for more sunshine and/or invest in a bigger solarpanel! Doesn’t matter which box i coose.

I am just at the beginning of testing this box, but for me it feels little awesome, what this powerstation serves!

20

Hi. I fix the issue in the same way. I’ve put inside the Nichicon capacitor 50V 3300uF and it works fine. If you worry to lose your warranty if you still have, you need to prepare some box with pv input and pv output and put inside this capacitor. Please keep in mind that the capacitor with electrolite has + and - pole so do not connect in oposite. So + goes to pv+ cable and - goes to pv-. By such box you dont need to disassemble the EB3A unit and you will fix the problem. I guess the Bluetti sets some safe margin as 10W that EB3A will not start below this power level as EB3A has own consumtion and to avoid drain the energy from battery during low light condition or small panel, Bluetti set 11W as enough to beat self consumtion. But I believe that self consumtion is rather something about 4-6W so this margin is too high and secondly EB3A has the issue with start charging from PV. I would say that you need 18W than the power can drop to 11W but still the starting point of charging is so bad. So I think there is an issue here and for most cases if you have lets say 100w pv panel capacitor works well and production is higher than consumtpion. I need to check what if we forget to unplug the pv panel after sunset if the batterry will drain or not but I will i form you guys later on.