Lenovo have recently released the new ThinkPad Helix to the western markets, which comes with the new 45 watts power adapter, which has the same rectangular power connector that are used on the ThinkPad X1 Carbon and X1 Carbon Touch. Some people are wondering whether they can use this 45 watts power adapter with their ThinkPad X1 Carbon/Carbon Touch, and thus not having to carry their 90 watts power adapter behemoth with their svelte X1 Carbon ultrabook, or fork out over $120 dollars for the 90 watts ultraslim travel adapter with the additional adapter head (another $20 dollars or so).
When Lenovo Australia finally released the 45 watts adapter on their website, i ordered one straight away (it costed around $40 AUD), and it was delivered to me within a week of ordering. The power adapter came in two cardboard boxes, which seems to be a waste of paper, since the outside box doesn’t really do anything. When i took the 45 watts power adapter out of the box, i noticed how small and light it feels in the hand. I took out my weighing scale out and measured the weight of the new 45 watts adapter versus the X1 Carbon’s old 90 watts power adapter. The 45 watts adapter with the AC cable weighs about 0.305 kg, which is about 0.185 kg lighter than the 90 watts adapter (0.490 kg).
The Helix 45 watts power adapter is slightly narrower and shorter than the ThinkPad X1 Carbon adapter, but the thickness is about the same (only about 4 mm difference).
The ThinkPad X1 Carbon weighs about 1.335 kg without power adapters, and weighs about 1.885 kg with the 90 watts power adapter included. Using the ThinkPad Helix 45 watts adapter with the ThinkPad X1 Carbon, the total package weight is about 1.640 kg, which represents a weight saving of 0.185 kg. The ThinkPad X1 Carbon power manager recognizes the Helix 45 watts adapter just fine, and there is no sign of overheating in the 45 watts adapter even when the ThinkPad X1 Carbon is stressed with CPU + GPU benchmark software. The only downside with using the ThinkPad Helix 45 watts adapter on the ThinkPad X1 Carbon is the fact that the battery takes about twice as long to charge.