Observation to conserve energy when charging laptop from powerstation

For my laptop I have a normal charger that uses mains, as well as a car charger that works on 12V. As a little experiment I tried both to charge with from my EC3A to see if there was any difference. And there was! The 12V charger uses almost half the power compared to the AC charger. I guess because the AC charger takes a higher voltage and then steps it down, while the 12V charger uses 12V directly, without a need to step it down, and so it’s more efficient.
Here is an image comparing the 2:

And this is the type of 12V charger I mean:

They are called “12V laptop charger”, “laptop car charger”, “dc laptop charger” or similar.
I hope this helps someone :blush:


Great post! I really want to move all my IT equipment to DC it’s so wasteful to go DC to AC back to DC.

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Yes, me too. It seems much more sensible energy-wise.

You can go even better if you use a USB-C to Thinkpad Adapter.
In your case you go from Battery voltage with a DCDC to 12V (13.5V actually) and with another DCDC to around 19V for the thinkpad.

With a usb C cable you can avoid one DCDC converter and go from power station battery voltage directly to 19-20V laptop voltage.


Great tip @bernad - thank you!

Generally its a great way to bypass DC-AC-DC Conversion. My laptop does have 100W charging via USB-C. This is fine for the most cases, but now much enough for Gaming. The 12V Outlet support 12V with 10A for the most Powerstations. That extra 20W might worth it to try. Thanks for sharing!

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