Powering P150HM with 90W adapter

I just wanted to share a little experience and get your thoughts about it.

Sometimes I forget my power brick at work, and one day wondered if it is possible to run my P150HM with Targus universal 90W adapter .

The adapter has few tips, after trying some I found tip# L106 fits P150HM well. I turned on the laptop with the battery installed and it worked normally (nothing special). When I took off the battery and turned on with the adapter only, the laptop started but it turned off immediately just before the windows login screen; and the same happened when tried to boot into Ubuntu.

I installed the battery again and it worked fine, the good thing that I was able to run the laptop, and at the same time the battery was charging till it reached 100%. (Other folks were complaining that Lenovo W520 can only charge the battery with 90W adapter if the computer is off or sleeping!)

Definitely I was not trying to play games on a 90W adapter, but I worked normally on the laptop for more than 6 hours (including running a couple of virtual machines). During this time I was monitoring the laptop temperature and the adapter temperature as well and both were perfectly normal.

I read some people claim that this is harmful to the laptop components, but this does not make sense to me because under normal load the laptop does not need 180W! also, the battery provides the laptop with 76.96W only and it is working without harming internal components (with low performance for sure)


Presumably worst case would be that the laptop will shutdown if the adapter cannot provide enough juice, or if the adapter is stupid then it will over heat and get burned (or a fuse get damaged). However, my Targus slim adapter is smart and it turns off automatically if the laptop tried to suck more power.


What I learned from this that I can comfortably travel with my slim adapter and run my laptop for normal load without carrying the 180W power brick. Any thoughts?

 

I say crank up a game and see what happens!! Or better yet, run FurMark or 3DMark or something along those lines and tells us what happens. We (ok, really just I) want to know.

I have a feeling that if you try to over draw the slim power supply, it will shutdown and you will start running on battery. But that is just a guess....


It is cool to know that there are other smaller, travel friendly power supply options out there. Thanks!

 

USNA 120 - Cooler Master - Leading Provider of Computer Case | Cooler | Power Supply

I think this 120W might be the perfect 3rd party power adapter, if it works well.

 

I powered the laptop with the 90W adapter (battery installed) and played the witcher for sometime. Before starting the game the battery was charging, but when I played for awhile I found the battery discharged a bit , but the laptop did not shutdown. I understand from this that simply the adapter turned off automatically (to not get burned) and the laptop switched to the battery. The funny thing that when I stopped the game the battery started to charge again.


I do not see any potential of burn for the laptop since it is not getting higher power, but the risk is really for the adapter itself; it seems that Targus compact adapter is smart enough to prevent self-damage.

Bottom line, it was possible to power the laptop for normal load and at the same time charge the battery with the Targus 90W compact adapter; when more power is needed, the battery starts to discharge.


For sure it is NOT wise to run the laptop at full load with less than the 180W adapter, but for normal load this solution might work well on the road and when the power brick not available. What I need to try next is to power the laptop, again using Targus adapter, but from a car charger!

I found a few alternatives such as Kensington 120W Slim AC/DC Notebook Power Adapter Review, which I believe will be better than 90W, but I only had access to the 90W adapter.

The key point is to make sure that the adapter is smart enough to turn off when required power exceeds the maximum capacity.

 

Kensington 120W Slim AC/DC Notebook Power Adapter is it good for light gaming?

 

Most likely not. Anything under the rated power supply would be unable to provide enough power for the machine under load. Unless your "light gaming" falls under something like flash games, the GPU is most likely going to ramp up and draw more power than a smaller adapter can provide.

 

It is not easy to tell because it will depend on the exact game you are planning to play and the GPU you have.

If you want to get an accurate estimate, you can get a device like Killl-a-Watt for about $20 and measure exactly how much power your laptop consumes while playing your game.

 

+ Rep.

Been thinking about this as well. Thanks for doing some testing. Maybe the Kensington 120W travel PSU is the way to go for travel/work purposes?

Hopefully one day (doubtful) we'll start getting smaller slimmer 180W PSU's...

 

Glad it helped. I do not have Kensington to test it, but the review I posted earlier seems positive. The only thing is to make sure that the adapter will turn off when laptop exceeds 120W, which you should not hit under normal load.

Smaller 180W PSU in the size of iPhone will be great, what is more likely, I guess, is to have efficient components (CPU & GPU) that provide the same performance with much less power conspumption i.e. Green Laptop

 

ok hope the dude that started this is still monitoring this thread,

but anyways, I have a p150 with a 2760 and a 6990 I want to know if we can get any slimmer power supplies going,

i do like your travel idea but i want one for gaming also, and no im not asking for a 90w to power this thing,

what i want to know, can you use the gadget thing that you have to tell me what the laptop draws when its under heavy use (gaming)

I want to see if maybe we can get away with a 150w, for example the stock power supply for the g73sw, my metabox works on it, just havent tried it the other way around.

also dell makes a studio line of power supplies, i think they are called PA-4E or something (just search power supply studio on ebay)

I have held one of these in my hands and they are the best on market power vs size. the 90w supply is 2 thirds the thickness of the tri-plug that goes into the standard metabox power supply and they also have a 130w adapter but this is alittle thicker (mind you its still almost the same thickness of three prong plug going into your stock powersupply right now.

let me know what you guys think, or tell em to get lost

 

I'm almost certain you won't be able to game with anything less than the 180w on the P150 with the specs you listed. If you use a kill-a-watt or UPS to show you the power being drawn under full load, it's not uncommon to see the power brick pulling 190-200w from the wall (which is even more than the conversion rating, due to inefficiency going from AC-DC). You could try a lesser adapter, but I'd bet that it would fail and revert you to battery under heavy load (assuming it's smart enough to not just burn itself up).

 

Just amazing how they pay so much attention to everything and then look past power supply design and backlit keyboard. But nothing can be perfect