How to power a laptop from regular 5V PowerBank?

Question

Lenovo

There is a Lenovo laptop with a 19V, 3.25A power supply. For a long time I wanted to increase its battery life, but the battery in it is non-replaceable. Somehow the idea came to mind to connect 4 identical PowerBanks in series to increase the voltage from 5V to 20V (by analogy with conventional AA batteries and with 18650).
I ordered 4 pieces of "3x 18650 PowerBank Battery Charger" from China, which come empty (no 18650 batteries).

I inserted 18650 batteries from old laptops into them. It is clear that they will work much less than new ones, but ideas will do for testing.
For the connection, I had to donate 4 USB cables, the microUSB ends of which were cut off and connected in series.
Output voltage measured: 20.5V.
Since the current declared by the Chinese for each of the PowerBank is only 1.5A. I assume that my output is 20.5V at 1.5A.
When you connect all this shit to a PowerBank laptop, they blink together for 5 seconds and cut down. I decided that it was precisely because of the insufficient current of 1.5A, with the required 3.25.
Then I connected all this to the LG 23EA63 monitor, which indicates the input power at 19V and 2A. The monitor agrees to work in the "Plug a cable into me, otherwise there is nothing to show" mode. But when I plug HDMI into it from a laptop, the monitor immediately cuts out.
The current thought on the agenda: add in parallel another bundle of 4 of the same PowerBank, thus increasing the current strength to 3A at 20.5V.
And now the question is:Ordinary batteries can be connected in series and in parallel and in series-parallel, but is it possible to mock PowerBanks in the same way?

Answer 1

That won't work.
Bank protection schemes can't work like that.
You'll have to make your own type https://usamodelkina.ru/9552-byudzhetnyy-power-ban... like this