Logitech Unifying receiver power usage

Hi, I've just realized that unifying dongle for my Logitech MX Anywhere is using like +2 W of power, regardless of whether mouse is on or off. It's about 20 minutes of battery runtime - I have T410s - every minute counts

Is anybody also experience such power usage?

P.S. Previous VX Revo was using zero watts...

 

how do you count it ?

 

Hi, I have reading in watts in Thinkpad Power Manager. I can post a image if you like.

 

Though I've never noticed a decrease in battery life with a Unifying dongle of the Anywhere Mouse, I'm going to test that out today. 2W is what a hard drive would consume. I seriously doubt the dongle is using that.

 

It must -- in order to work, it transmits a wireless signal which means energy. The more different signals, the more energy you spend. That said, I have not seen any difference in battery life with my mouse so I don't think it's 2 Watts.

 

Did the test - ran for 20 mins with dongle plugged in. Recharged. Ran for 20 mins dongle out using touchpad. Battery reached the same level of discharge in 20 mins (give or take a a few tenths of a percent) in both instances.

Which would make sense since RF uses considerably less power than Bluetooth devices.

To the OP, are you sure the software said 2W and not 2mW?

 

Recharging the battery as a test of power used (analogy to estimating car mileage) is not a good idea...

I have estimated power usage by observing the watt output and battery time.
My methodology was as follows:

During observation I left laptop with no app active - idling (observing the cpu usage and apps activity via taskbar and resources manager) with dongle plugged in reading was: 14W

NO OTHER DEVICES WERE PLUGGED IN!
LOGITECH MX ANYWHERE WAS OFF FOR THE WHOLE EXPERIMENT!

after 15 min I've unplugged the dongle and wait another 15 min.
The power usage dropped instantly from 14W to 12-11W.
Battery lifetime up by ca. 20 mins.

This test verified that by only letting the dongle in the usb port it drains battery. This may be connected with issue where it is impossible to turn off MX from waking up computer under Win 7.

I have T410s, WIN 7 PRO x64, 14", Intel HD, 8 GB RAM, 128 SSD, 6200abgn, WWAN.

 

If the dongle is in fact using 2 watts that means that tiny little dongle is using .4 amps of current. Sorry, as small as it is it would be to hot to even touch if it was using 2 watts.

Mine gets warm to the touch. but it is no where 2 watts hot to the touch

 

I think you misunderstood how I did the test. Battery was @ 100% at the beginning of EACH test. I needed to recharge the battery AFTER/BETWEEN each test back to 100%. The 20 minutes is the run time of each test. Both tests discharged the battery from 100% to about 73% in 20 minutes.

How else could you determine REAL WORLD use except with a real world experiment?

 

It "guesses" just like Battery Bar does. Only way to be sure of a real world result is with a real world experiment.

And they both(SIW and Battery Bar) report the same mW.

While the OP is worried about possible battery life degradation, he's basing it on estimated reports instead of actual use.

It is sort of like guesses how many FPS you'll get using 3Dmark instead of actually playing the game or going by the reports of those who have with a similar setup.

 

The notebook I tested it on gets 2 hours doing basic things. That's why I chose 20 mins to test which represents 20% of it's lifetime. The difference between the two was too insignificant to attribute an extra power drain to the dongle.

And I believe he said that the estimated battery life changed by 20 mins:

That's an estimation of the program he's using which determined that the dongle used 2W.

 

Power is defined as the rate at which work is performed or energy is converted.

2 watts in such a small package would still be pretty damn warm, even if it was converting most of that 2 watts into the transmitted power, mechanically the heat has to go somewhere.

Besides I looked at the power used in device managers USB hub device on both my laptops and they report 98ma and 100 ma respectively This seems much more reasonable at .5Watts.

 

you're assuming the program is built perfectly and that sensors work properly.

both are very big assumptions to make.

the best way to test this is to drain the battery all the way and with using a stopwatch.

 

I'm looking at my battery bar with the receiver and it's not remotely close to 2W. My real life usage with it in and out shows almost no disparity...if so, it's so inconsequential it's not even noticeable.

 

Keyhuynh,

we are falling on deaf ears I think, My quote above was totally ignored, If the OP would go look at the USB HUB device in device manager, you can get a much more accurate indication of the power actually used by the dongle.

 

well for OP rather than worrying about reading from softwares ..
just see if there's any difference in real battery life when using it with and without the dongle. And report back here.
I'm sure you'll have nothing to worry about after.

 

Software monitoring has never been 100% anything from tempatures to voltages can be wrong just because the software does not know how to read the sensors or has incorrect data.

If you really want to know how much power it uses spend $20 for a device I have called the Kill-a-watt it will give you real life wattage readings for the computer at a hardware level.

Just take out your battery, plug the laptop into the device, plug the device into the wall.

Idle on the desktop and look at the wattage, then plug the usb reciever in and see if it goes up 2w.

This device is how I come up with my power draw figures posted on my laptop reviews.

http://www.google.com/products/cata...S9J5iCygWmyqSXBA&sa=title&ved=0CAcQ8wIwADgA#p

 

Too funny. I have one of those I use all the time. A Kill-A-Watt P3.

So I tried it out using it and guess what? Zero change in watts. Same results as the real world battery test I did showed.


With battery in while on AC: idled at 29-30 watts with the dongle in. Same with dongle out.
With battery out while on AC: exactly the same as above.

 

I checked my computer at work and the USB hub shows 98ma. Remove dongle now reads 0ma, So I have three different computers all using different southbridge chipsets with usb built in and all three are within 2ma.

These dongle use .5W not 2 watts.

I am so done with this thread.

 

Yes. I think it's been proven conclusively that the Unifying Receiver uses an inconsequential amount of power.

 

I had to weight in with my opinion..... I really don't think anyone has proven anything in this thread. Does the dongle use 2w? No probably not, however you aren't considering all factors.

First off, the Lenovo software reports the power coming out of the battery. No, it's probably not absolutely accurate, but I'm pretty sure it has more resolution than a kill a watt.

Second, this goes beyond just the dongle. I notice a similar increase in power usage on my machine with nearly any active USB device plugged in. It's not just the power used by the dongle, but also the USB hub not being able to be put to sleep. You have to power the entire hub as well as whatever is plugged into it. I can certainly see this being a small 2 watts.

Lastly, the test on AC is a poor test. 1, you used a kill a watt, which is not the easiest thing to 2 watts on. 2, you did it on AC when the machine isn't trying as aggressively to put things to sleep. The USB hub may have remained fully powered during that test.

So I'm going to say this is all inconclusive. I agree that the dongle doesn't take 2 watts to run. But if it's the difference between a powered USB hub vs a sleeping USB hub..... the jury's out.



Cheers

 

PS. Sorry for reviving an old thread :-(

 

Yep. even a 4gb usb memory stick increases laptop draw by 2-3 watts when NOT in use.