Possible to use the 520W with the 90W adapter?

I'm quite interested in the W520, but the thought of lugging around the 175W adapter makes me shiver. Will the 90W power the W520? Will the 90W recharge the 9 cell battery?

I realize the 90W may force the W520 into a lower power mode when running on AC power, but I think I can get around that by charging it overnight and only running on battery during the day. When I travel I don't do much "heavy workstation" work, so I could probably live with the lower power mode as well during those days.

I've been googling, but have found opposite answers. For example, in Keith Combs' review he states the 90W adapter will not work with the W520. But in this post the poster says the 90W adapter will work.

Can anybody tell me what is going on with the 90W adapter and the W520?

 

I wouldn't recommend it. Alot of notebooks will throttle CPU/GPU to unstable levels. Also if you are running your laptop full blast it won't charge the battery.

Just one of the downfalls of a mobile workstation, carrying around a mini-nuclear power plant.

 

In the picture found here, the connector heads are different.

 

Yes, but when I travel I don't need to run my laptop full blast. The W510 used 93.6W at full load so surely a 90W adapter could have been used at with some sort of a lower performance, but stable, mode for the W520?

Yes, but he also says the older 135W adapter (same connector as the 90W) will work with the W520. I think only the 175W W520 adapter will not work with older machines.

 

Like the W510, the 90W will work in some capacities. It will charge the W520 battery when the machine is off. That's about it.

You only need the 170W power supply if you are using the extreme quad proc. This is explained in the video at YouTube - LenovoVision's Channel.

The 135W power supply will work fine but it isn't exactly small or light.

 

I have been lugging the 170 W brick for a couple of weeks now and in my briefcase it is not really a noticaable load. It certainly is larger than the 65w bricks I have been using with my T61, but not a real problem.

Perry

 

Has this been verified? You have tested it and it will work for sure? I'm not challenging your assertion, I just want to know for sure.

I have to say, this is disappointing for me to learn about. I realize the W520 is a workstation and needs a high wattage power supply at full blast, but I wonder if it could have had some conservative power profile that could have enabled it to run with the 90W supply. Does it really have to throttle to a basically unusable mode? Support for a 90W adapter would have made traveling with it easier.

 

I was basing my comment on the 3/30/2011 update at The Lenovo ThinkPad W520 i7 Quad Core has seven hours of battery life? Really? - Keith Combs' Blahg - Site Home - TechNet Blogs. Looks like the 90W will at least charge the unit overnight.

I haven't even bothered to try the 90W much with mine. If you tried to use the W510 with the 90W adapter, it would throttle the machine performance down too far. The workloads I normally run require external power so traveling with the 135W charger makes the most sense for me.

 

I have occasionally been checking the power consumption of my (i7-2720) W520 with a watt meter, and during normal surfing and watching Netflix it usually stays below 50 W, often even just in the 20ies.

Only when I ran the WEI it went up to 120 W a few times when testing graphics performance.

From these observations it should run on a 90 W adapter under light load.

 

Yes, I assumed as much. But when I searched through for comments on using the 90W adapter with the W510 and W520, it seems the laptop is throttled to a basically unusable level. Maybe I am wrong, but I think Lenovo could have enabled this, even if it meant only using the IGP and disabling the discrete GPU completely.

At least the laptop can be charged with the 90W adapter. At one point one of my friends had a Dell laptop that would not even charge the battery with a different adapter...

 

I'll try to run mine with the 90W today and see how it does.

 

Ok, here's the skinny. When you run on the 90W adapter, it appears to have zero effect. You might as well be on battery. I didn't sense any performance drop or weirdness.

So you can travel with a 90W and charge overnight (though I haven't fully tested that), it would seem if you run out of juice during the day you are going to be screwed.

In short, use the 135W or 170W.

 

But was the computer actually running on battery?

John

 

I have the same question. Was the battery discharging? Was the battery level staying the same (neither charging or discharging?).

 

Yes, discharging as if it wasn't plugged in.

 

Has anyone tried to charge a discharged battery with a 90w or 65w with the computer off?

I will try it tonite.

I am typing this with a 65w plugged in, but obviously it is likely operating on battery. So the older plugs will at least insert in the female connector.

Someone has posted performance suffers, but as I don't have any saved benchmarks both ways I can't commment on that.

When I plugged in the 65w baby brick, the computer gave me a message that the wrong adapter was plugged in. Also the battery did not change to the socket showing it was charging.

Perry

 

Yes, I tried recharge the battery last night using 90W power supply and the battery was recharged 100% this morning.

I am wondering whether there is alternative power supply than what Lenovo provide. Is there a smaller/lighter third party power supply like 120W that will works with W520?

 

I concur. I used the 65w baby brick from my T61 and this morning the battery was 100% charged.

So if you want only computer off/overnight recharging you can travel with the smaller brick.

I don't think you can get computer on/working current however.

Perry

 

Here's another thread discussing the Power brick forum.thinkpads.com • View topic - W520 requires 170W AC adapter