I have the EB3A (EU version) with PV68 solar panel, but solar charging does not work in practice. The EU version of EB3A is still stuck to the old firmware versions (ARM 2053.07, DSP 2052.04), with no update offered in the app.
These firmware versions have an issue that the PV input does not start charging under about 18W, and if it sees a lower wattage input to start, it goes into the error state (PV low voltage), and that error state remains (even if the voltage goes up) and prevents charging. And, not only is it not charging, but in that error state it actually consumes 1-2% battery per hour!
In practice this means that it is not possible to charge with solar panel except in perfect conditions, and even if you start charging fine, leaving the panel plugged in overnight means it will go into the error state at night and then start draining battery instead of charging.
So, again, to clarify:
Plug in solar panel with 18W or more output, then drop down to 1W: charges ok (but dropping down to 0W at any point leads to the case below):
Plug in solar panel with 1W output, then increase to 18W+: does not charge, drains battery 1-2% per hour
This issue has been discussed in various threads on this forum, and has been reproduced by multiple people. There are some threads about the US version that suggest this would be fixed in firmware update to version .11, but these threads are over 6 months old and still no update in EU.
I also sent a service request about this issue in the Bluetti iOS app, but there has been no response to it for 2 months.
Can you please fix this issue? If it is a matter of firmware update, please make the relevant fix available to EU customers, as this problem effectively prevents solar charging even with your own panels (like the PV68 that you sell as a bundle with EB3A). If it can’t be fixed by firmware update, then please respond to the service request and fix the hardware under warranty.
What solar panel are you using that won’t get more than 18W? Or is it because the sunlight is weak?
As said in the OP, the panel is Bluetti PV68. The issue is that if you ever start charging in weak light below 18W, the EB3A (EU version) goes into a “PV voltage low” error state, does not charge, and drains battery instead.
So, again:
If you start charging at 18W or more, it works fine, even if level of light drops down and you get only 1W, it will still charge
If you start charging below 18W (e.g., leave panel plugged in overnight when charging drops down to zero in the dark hours), it will go into error state and not start charging even when watts go above 18W → can’t leave panel plugged in overnight or it will drain battery next morning
Hello,
I have exactly the same behavior with the bluetti PV120 solar panels and my eb3a.
I wrote to bluetti via App, but I don’t think it was successful because I haven’t a reply for my message…
I have the feeling bluetti has no software solution or no interest in solve the issue.
If I had known about it earlier I hat bought an other brand.
Let’s see what happen here. Btw in live in Germany.
I also have had no reply to the report sent from the Bluetti app 2 months ago. However, I also emailed their EU support (sale-eu@bluettipower.com), and they replied in one day… Sadly, the response was unhelpful, i.e., asking to measure the panel voltage and check cable length, etc., but maybe it is possible to continue conversation from there (haven’t heard back after I responded again).
The frustrating thing is that this is almost certainly a very small firmware fix away: clear the “PV voltage low” error state instead of staying in it. =(
I tested it with 3 different PV120 Modules. In bright sunlight about 110W max Solar Input which really is good, with upcoming dark clouds lower and down to almost zero, no input flashing. Until here normal behaviour.
When i replugged the Panel under 10-15 watts than input is only flashing until the sun comes back.
In Winter times, with less light even 2 parallel attached pv120 did not charge, only flashing while my Roof Solar Panel (380 W) is producing roundabout 35 Watts. For me with no direct sunlight in my garden the device is unusable in winter Times. I didnt try all 3 Panels in parallel bc i havent got an adapter for that.
@BLUETTI Have you maybe got news / Updates / Knowledge with this Problem?
Some devices have a minimum power cut off, if your roof 380W panel are only generating 35W, then a 120W PV would do maybe only 10W, though I would think 2 in parallel should do 18W with some additional losses and mismatch. While it isn’t ideal, I am not surprised that it won’t take a charge when there is so little power available.
Is it a cloudy day? Where do you live where sun in winter produces <10% of solar panel power?
I have another brand solar charger / inverter / battery combo, and I do noticed a similar no charge at lower sun input situation. When there are lots of clouds, the power would drop to 0W. Actually the MPPT would try to charge and power would go from 0-10-20W and then back to 0W, stay there for 10s and cycle again. I am running 2s 120W into it. This issue may not be unique to Bluetti
I have another brand solar charger / inverter / battery combo, and I do noticed a similar no charge at lower sun input situation. When there are lots of clouds, the power would drop to 0W. Actually the MPPT would try to charge and power would go from 0-10-20W and then back to 0W, stay there for 10s and cycle again. I am running 2s 120W into it. This issue may not be unique to Bluetti
If the EB3A recovered after 10s, it would be fine, but once the charge falls to 0W it will never recover without manual intervention, and instead of charging it will drain the battery 1-2% per hour with no load connected. That is unique to the EU version of EB3A, even other Bluetti power banks do not have this same issue.
@Arkku Are you charging on a cloudy day? The input power will be very low this way. When the solar panel’s ISC reaches the EB3A input current minimum, its input voltage will decrease rapidly as the input power gets smaller, and a PV low voltage error will be reported when it is less than 12V.
Are you charging on a cloudy day? The input power will be very low this way. When the solar panel’s ISC reaches the EB3A input current minimum, its input voltage will decrease rapidly as the input power gets smaller, and a PV low voltage error will be reported when it is less than 12V.
@BLUETTI_CARE I understand that on cloudy day or at night this error state may appear. That is not the issue. The issue is that once this error state appears, it does not go away when the light improves, and the battery is drained while in this error state even with no load connected.
Again, please consider this example:
I plug in the panel in good sunlight, get 50W charging
Time passes and sun starts to set, now I get only 1W charging
Sun sets and panel is still plugged in, but there is no light, so charging stops (0W)
Sun starts to rise, first rays of light would give 1W charging, but the voltage is too low to start → PV voltage low error state happens, and battery drains at 1-2% per hour even with no load
Sun has risen, now there would be 50W charging again, but because PV voltage low error state it won’t charge and instead battery continues to drain 1-2% per hour
Steps 1–3 are normal and understood, it depends on amount of light. Steps 4 and 5 are the problem: if the charging ever starts from 0 to less than 18W, it will go into PV voltage low error state and not recover. So, it is not possible to leave panel plugged in overnight or unattended, because sun setting (or heavy cloud appearing) will enter the persistent error state and drain the battery.
(I’d also like to reiterate that this same issue has been reproduced by several other users more than 6 months ago, and appears to have been specifically fixed in the US version firmware update, so at some point someone at Bluetti has understood and acknowledged this problem, but EU version is still not fixed. See linked threads from first post.)
I received a firmware update to DSP version 2052.09 now. I tested it as follows:
2 pm: EB3A at 90% charge and nothing connected, DC off: plugged in the PV68 panel, but there was no direct sunlight: the “PV voltage low” error appeared as before, so the solar charging still can’t start under 18W
3 pm: EB3A at 89% charge, still no direct sunlight and showing the error, so the battery is still being drained in this state
4 pm: EB3A at 88% charge, but now the sun has moved so that the panel is getting direct sunlight: charging at around 25W
After that, I experimented by moving the panel partially to shadow, and found that the charging would stop at around 11W completely, and start at around 20W when moving it back
(edit: added this point) 6 pm: EB3A at 93% charge, now the sky is overcast, but no error state and the app shows that it is still charging at 1W – so, low W charging is still possible if it slowly drops to it
In conclusion: the firmware update is a definite improvement in that it makes the PV voltage low error recoverable, but does not fix all issues. Specifically, it fixes one of three related issues:
Once the PV voltage low error state happens, it was not possible to restart charging: this is fixed now by the .09 firmware
The battery is drained by 1-2% per hour while the PV voltage low state occurs: this is not fixed, so leaving the panel plugged in might still lead to a temporary drain on the battery (perhaps over 20% drain in total if the error state would persist overnight, and theoretically a complete drain could happen during multiple consecutive cloudy days, so the panel can’t be left plugged in “permanently”)
The charging can’t start at low watts – if even 10W start was possible, this would considerably extend the weather conditions for charging, but I can understand if this is not possible to fix in firmware
So, we are getting some improvements here with the error state no longer “fatal”, but I wish it was still possible to improve the battery drain (e.g., don’t keep the screen on in the PV voltage low error state, if that’s what is causing the drain).
Next day update: the EB3A and PV68 have been plugged in for over 24h now. The battery went down to about 70% charge (from original 90% and peak about 94%) due to the PV voltage low state draining battery, since it has been cloudy today. So leaving the panel plugged in is still a gamble where you may well lose charge rather than gain it…
In the evening it is charging at 1W again; there was a momentary ray of light that turned on the charging, now it is cloudy again.( I don’t really understand why it is possible to continue charging at 1W but not start charging at 1W…)
edit: Next day update #2: another cloudy day, now it is charging at 3W but the charge is at 55%, so leaving it plugged in is still a net negative.
Hi, it is not suggested that you connected the solar panel overnight. That would cause much consumption than disconnect the solar panel. Furthermore, I contacted Bluetti Technician, and received a reply that currently there is no firmware can help to decrease consumption.
I agree that not leaving the solar panel plugged in overnight does solve the battery drain, but I do not think it is an acceptable limitation for the product that you can only solar charge it under constant supervision or it will result in negative charge…
I am in Australia and purchased my EB2A in April. I am having the same issue, connected to the solar panels in full sun for 3 hours, there was as drop of 4%.
Not charging from solar panels response from Sale-au within hours, this is the reply.
Sorry for the problem.
Here are the solutions for you:
1. Please check whether the EB3A is fully charged? If yes, it is normal that can not be charged when EB3A reach 100%.
2. If the ‘input’ is flashing, you need to check whether the open circuit voltage(voc) of your solar panel exceed the PV input of EB3A(28V).
3. Please try whether EB3A can be charged by car. If it can be charged by car, then it may the problem of solar panels.
Please use a multimeter to measure the voltage of the solar panel and connecting cable.
We will wait for your feedback. Please provide a video shows the problem then.
My reply.
The EB3A was at 84% when I attempted to charge.
There the “input” was not moving at all. The solar panel does not exceed EB3A’s 28v
The car charger works ok.
Have tested the solar panels and there is no problems there.