I have seen Dell 130W, Lenovo 120W, some 230W or 210W gaming laptops, etc. . These are different numbers.

But I have seen both 65W and 90W power supplies from Lenovo (65W 20V 3,25A with rounded DC connector (built 2007) and Lenovo's proprietary rectangular DC connector (built 2015)) and Dell (65W 19,5V 3,34A) and HP (65W 19,5V 3,34A) and Asus (65W 19V 3,43A). A quick internet search suggests that Acer also uses 65W 19V 3,43A known from Asus.
I have seen 90W power supplies from Lenovo (20V) and Dell (19,5V) as well. The other manufacturers have power supplies at that wattage as well, very likely.

The wattage is the same, while the voltages are slightly different. Why that is, that's a different question, but I am not sure, whether it is sufficiently relevant for Electronics.StackExchange.com. If it is, please let me know.

Why are 65W and 90W power supplies common amongst different manufacturers of middle-end laptops?

Why not 60W, 70W instead of 65W? Why not 100W instead of 90W?
Manufacturers use different power connectors, yet the same wattage at a very similar voltage.

(There is nothing wrong with 65W and 90W, I am just wondering why different manufacturers share specifically 65W and 90W. If it is an industry standard, how exactly was it specified?)

  • 3
    \$\begingroup\$ I'll leave answering for someone who is certain, but this probably is the result of optimizing the performance of very similar sets of lithium ion batteries and also sometimes rebranding might be a factor. \$\endgroup\$
    – K H
    Commented Sep 15, 2018 at 17:51


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.