Pass Trough when charging from solar panel

I would like to know if it possible to pass trough EB3A from solar panel to my laptop when the Powerstation is full charged ?
Thank you

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Hi @DenisTH

in the official FAQ of the EB3A is the following question:

Can it charge and discharge at the same time?

  • Yes

So i assume this shouldnt be a problem.




Yes, I think that would work. I have’t tried with a laptop yet, but I did try with a phone for example and also an external, small powerbank. Both charged fine, while the solar panel was connected and the EB3A was charged at 100%.


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Thank you for answers. Sorry, I missed it. English is not my language.
What I mean is: can the laptop draw directly from the electricity provided by the solar panel or does it draw from the battery which is then recharged?
Until now, from what i experienced, the laptop draws from the battery which recharges simultaneously on the solar panel. But it’s not Passthrough… Passthrough seems to work only from AC plug

Hmmm, okay. I wouldn’t know how to test if it’s passthrough or not.

But in practise, would it matter? Because if the laptop takes from the battery, and then the battery goes to for example 99%, the solar panel would top it up again right? Or are you worried about cycling the battery?

Yes, but what are the consequences on long term about the battery ?
When i tested, as soon as the battery is 99%, it starts to charge from the solar panel.
Until now, i do this way : i plug my laptop on the EB3A until the battery is 50%. When 50% only, i replug the solar panel to the battery, to avoid small charge and discharge

This may be useful information:
BU-808: How to Prolong Lithium-based Batteries - Battery University
About 20% down the page there’s a table that compares Depth of Discharge with the number of discharge cycles you’d expect to get from your battery.
To me that table suggests that if you would discharge only 1% you should be able to get very many cycles. But below thet table they also state that Cycling in mid-state-of-charge would have best longevity.
So going to 50% might make the most sense indeed.

@DenisTH Are you using a DC-DC adapter to charge your laptop? Or an AC-DC adapter? Perhaps there’s a difference there too. Personally I noticed if I use a DC-DC adapter plugged in to the 12V port, charging the laptop takes less power.

The real number of charging cycle seems to be a sensitive topic for all powerstations makers. :slight_smile: It is almost impossible to get the truth. I’ve already got bad experience with my old Goal Zero and now, i am suspicious. I could not say what is the best way to do : small charges or 50%.
With powerstations, it is almost impossible to change the battery : too difficult, no spare part or the product is often discontinued when problems occurs.

About the laptop… Until now, i am testing this way : I just plug my laptop in the AC plug of the EB3A.
It is a very good autonomy

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Good insights @DenisTH; thank you for sharing them. Overall, would you say it’s worth it (financially) to work with these powerstations? Even if they stop working at some point like your previous one?

To be honest, Bluetti will be my last attempt with POWERSTATION.
What i am looking for is not saving money, but getting more autonomy about energy. I tested with differents brands and models of powerstations. Unless they improve their products with a possibility of battery replacement (and other parts too), i use it only for “not important” needs.
When there is any problem with a powerstation, all your system is down, and it is almost impossible to get it repaired quickly. That’s why i already have 2 others simple independents and cheap solar sets beside for 12V devices and lamps. In case of electricity outage, i use them…
Now, i am preparing for a less integrated system because i also want to be more independent about repairing, in case of problem. The MPPT is dead, i go to the shop, i buy one, i replace… ;)

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Yes, makes a lot of sense. It’s good to be independent/more autonomous with these things. I like your thinking. Thanks!

The solarpanel delivers 30V DC, the Laptop Powersupply needs 230V AC. So ther will never be a direct passthrough. It needs to be converted.

But what i figured out: when the Solarpanel e.g. delivers 100W and the laptop only needs 50W then the 50W goes directly to the output after conversion from DC to AC and the battery is charged with around 50W (less conversion loss).

If the battery is fully charged, then the MPTT Solar inverter is turned of so the Solar panel does not deliver any power and the laptop is charged from the powerstations battery until the battery reaches 99%, then the MPTT Solar inverter starts again.


@OpaleTrotzig I have seen so many posts here and on Facebook saying that all of the incoming DC power must charge the battery first and discharge the battery to power the loads. Your example with the 100 watts in and 50 watts load with the battery charging with the remainder is great.
Another example is where 100 watts is input and 150 watts is being output to the load. Absolutely no charging can take place because the battery has to be discharging with 50 watts to add to the input which is passing through to the load. Batteries cannot charge and discharge at the same time but these Bluetti units make it “appear” to be doing that.
The end result is that not all of the power coming in is contributing to battery charge/discharge cycles. But it seems like many believe that. Thanks for your post.

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Thanks @OpaleTrotzig and @PaulL71 for these examples. That clarifies things.

Would be so cool if in this scenario the MPTT charge controller could directly pass the power on to the laptop. That way you wouldn’t be stressing the battery in any way, while still running your laptop on solar :sunny:

Thank you to everyone for answering.
Actually, even i am not a battery specialist, i believe that’s not good for the EB3A battery to be charged and discharged 1 or 2% only each time, when a laptop or any other device is connected to the EB3A AC plug : Probably memory effect and cycles use. I would appreciate that BLUETTI clarify this question, because nothing is really explained on the website or in the user guide.

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