Help me buy an AC adapter

July 28, 2011 7:36 AM

Can I buy a 90W Power adapter for a 65W adapter? The description of the product says it is compatible with my new Lenovo T400, but I don't understand electricity so I thought I'd ask.

Please help me understand AC adapters.

I would like to buy a spare AC adapter for my new computer. Can I buy a 90W adapter for a 65W adapter? The description of the product says it is compatible with my Lenovo T400, but I don't understand electricity so I thought I'd ask.

Original, definitely works with my computer:
Authentic Lenovo AC adapter
Power management Connector Description 3-pin
AC Input Voltage 20.0 Power 65 W
Power supply type 100-240 volt AC

Want to buy, says it is compatible:
Power Input: AC100-240V - Output: 20V, 4.5A, 90W - Tip size: 7.9*5.5mm Central Pin


Also, I have an old power cord that is 15V. Can I use it with this computer that calls for a 20V input, or is that a bad idea?

Thank you.

posted by vincele to Computers & Internet (6 answers total)

Best answer: The volts and connector type need to match, but the wattage can be the same or higher.
posted by damn dirty ape at 7:46 AM on July 28, 2011 [2 favorites]

Best answer: I can't actually answer your question, but I will note that 90-watt adapters are often heavier than 65-watt adapters.
posted by grouse at 7:48 AM on July 28, 2011 [1 favorite]

Best answer: Yes, it'll work, but as Grouse said, it's almost certainly going to be bigger and heavier than your existing adapter.
posted by deadmessenger at 7:51 AM on July 28, 2011 [1 favorite]

Best answer: Higher wattage is fine, transformers are rated for their maximum output, so hooking up one with more capacity isn't going to wreck your computer.

The lower voltage one on the other hand, well I doubt it would work.
posted by Pink Fuzzy Bunny at 7:52 AM on July 28, 2011 [1 favorite]

Response by poster: Thank you all, I appreciate your speedy responses. I'll go ahead and order two of the cheaper model.
posted by vincele at 8:02 AM on July 28, 2011

Best answer: I did a similar thing, I use the smaller one for travel and retired the larger one to power a docking station at home. No regrets in any way/shape/form (and my whole family has Thinkpads btw, I don't know about the new ones but the T6X models are real troopers).
posted by RolandOfEld at 8:10 AM on July 28, 2011 [2 favorites]