laptop power supply now lightweight

 


Powering (or charging) a thinkpad used to involve a thick three-core mains cable with plug, a large transformer unit, and a DC lead integrated with the DC jack for the laptop end.  The full assembly above comes in just short of 500g.  It's always been 20V.

It was possible to save some travel weight by making your own very short mains leads, splicing the DC lead, buying an alternative transformer, and so on, but not by much.  I even saved some weight by importing A Merkin lenovo transformers, which are perhaps class II appliances, but in any case had a two-connector figure-8 (C8) connector, only requiring a thinner 2-core mains lead.  But the transformer was always big.

On their way to USB-C PD, thinkpads had a variety of other DC inputs: the square one, the thin round one.  Even when thinkpads, for example the X1 Carbons, started to have USB-C PD inputs more than 5 years ago, lenovo shipped them with bulky, heavy power supplies, with the transformer still in its own black box, and the mains lead still required.  The earlier generations of x1 carbon with USB-C PD were picky about their power supply.  I never worked it out fully, but it may have been as simple as requiring 20V to be negotiable.

The lightest practical setup for powering my 8th gen x1 carbon is pictured right, at 69g.  The europlug power supply alone is 50g.  Model U60-PD20W, brand Anigaduo.  With a 0.9m Amazon Basic USB C-C cable.  The power supply only does 12V, not 20V, but the laptop is happy with it.  The whole thing now slips into a briefcase without noticing, rather than being a bulging adjunct to the laptop.  The apple cables have a nicer feel, but I can't put my hands on a 1m one right now, only 2m, which is too long.

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