Probably better to just buy a second or high capacity battery, it may cost the same as a external USB monitor but double the run time.
The only time I could see a reason for a USB monitor used the way you describe is if power is hard to come by, such as a solar panel as the only source for a cabin in the woods
Perhaps I was hasty in saying that such a device wouldn’t be made, as apparently one has. I revise my answer to your question as follows:
Mini USB monitors are not a widespread way to get a laptop to run longer on battery because the number of people who want to use a 7" screen is vanishingly small. Just because you’re in this minority doesn’t make it not a minority.
Your judgement of consumer priorities is astoundingly off target. The relative benefit to most notebook toting people in being able to squeeze out some extra battery life compared to the cost and hassle of dealing with lugging a 7 inch USB driven and powered screen along with the notebook is minuscule.
If maximizing non-AC up time is a prime concern an extra battery and power sipping notebook/netbook are a far more efficient solution than your extra screen proposal.
I do *not *want to start a tit-for-tat hijack of the OPs thread.
I agree with you 100% that many will be handled as you say: handed down or sold.
But many won’t. Per this badly translated Chinese article CcnInfo.com is for sale | HugeDomains IPad sales are 15 million units to date. That 7% of them will end up in landfills seems to me to be a slam-dunk, not a ridiculous exaggeration.
I don’t sell things on eBay. Nobody I know does. Too much hassle to set up a selling account for one item. And who’d buy an expensive piece of gear from somebody with no feedback? Popular electronics are magnets for unscrupulous sellers which leads (I’m told here) to over-wary buyers.
If indeed Apple offers some trade-in deal where they handle the recycling, that’d keep (some parts of) some of them out of landfills. I don’t follow Apple’s consumer policies so I can’t say. Heck, they might find it makes business sense to take them in trade & grind em up into the landfill just to keep them off the secondary market & thereby support the primary market, ie. new unit sales.
My bottom line, and yours may vary: A small percentage of IPads will end up in basements to eventually end up in the landfill or get pitched to promptly end up in the landfill. Given the many millions sold, more than a million units will suffer this fate.
As an aside, and not a parting shot. … I like how somehow the term “upgrade” is now used to describe “buy a new one for full price & trash / recycle / hand down / sell the old one”. You’re by far not the first person to use this terminology here. The marketers have really had their way with us all, myself included.
Every one of those responses you called noise actually answered your question as you asked it. The reason no one wants it is that it defeats the purpose of a laptop. The whole point is that it is a self-contained and portable. And most people do not want a smaller screen, so they would have to plug in any screen that they would use.
And seeing as you only discussed battery life in the OP, that is something you missed, and thus a direct answer to your question. I’m sorry they weren’t the ones you were looking for.
Because its incredibly inconvenient compared to the typical alternatives. For instance, when I fly I pack two laptop batteries. This is cost effective and doesn’t take a lot of space. I don’t need to carry some mini 2nd monitor (note that resolution is an issue with USB powered monitors). A 7" monitor would be useless for my needs and for the price of a monitor alone I could get a user Color Nook or other low-end tablet/netbook to do things with.
Secondly, the power savings may not be enough to justify the expense and hassle. My Macbook with an Intel SSD lasts me 4 hours on the plane watching videos. I really don’t need an extra hour or even two. If I did I would have a second battary or migrate over to a netbook/tablet. This would a hard sell to geeks like me or to average users.
The answer to the OP is that nobody wants to trade screen area for battery life like this. Or, at least, very few people want to.
The reason you can tell is that what you’re asking for could easily be accomplished in the video driver using this method. No extra hardware would be needed, but even without that cost, nobody bothers to implement it.
iamthewalrus,
could you please elaborate on how you would use a video driver to reduce power consumption of a laptop monitor? I always thought that the monitor spends a fixed amount of power for its backlight, and you cannot make the backlight illuminate only a section of the screen.
Or maybe some screens have multiple discrete backlights so that some could be turned off to save power?
Yeah, on an OLED screen, you could save power by turning off a bunch of the LEDs that make up the pixels, and just leave a smaller portion in the center on. But most laptop monitors are not OLED, they’re LCD, where the backlight is indeed one solid panel. Last time I did any research, only phones (and maybe some tablets, I can’t remember) are using the AMOLED displays so far, because an AMOLED display only saves power with mostly-black displays; for a white-background website or word processor or whatever, the AMOLED displays use about 3x the power of the equivalent laptop display.
This may have changed since I read up on it, though. But in any case, on most laptops with larger displays, the backlight can be brightness-adjusted, but not have discrete sections turned off.
Many modern laptops do in fact have multiple LED sources that presumably could be powered independently (though even in that case, it might take more than a driver change. It would depend on how the backlight circuits are designed).
I’m not sure if that would degrade smoothly. You’d probably get some light bleed into other portions of the screen. But who cares. You’ve already decided to accept a sub-standard video display to save a little battery life.
The point is that it’s pretty easy to make a laptop screen that will degrade into a much poorer visual experience to save battery life without hauling around extra hardware, but even the easiest and cheapest solutions aren’t out there because this isn’t something that many people want.