I have an HP Pavilion DV7T Quad Edition - i7 1.6ghz, GeForce GT 320m, 4gb of ram and now dual HDDs. Needless to say the thing goes through battery power faster than a coke head blow; usually to the tune of 45-50 minutes of life just casually browsing the internet and writing notes during classes. Since Linux doesn't pound the video card using Gnome or KDE like Aero does that would obviously save on some juice. Would using a driver that enables full 2D for a smooth UI experience but doesn't have any 3D enabled save on battery life further? Just flat out not turning on features of the card? I've considered other aspects of the laptop for power conservation but short of turning the brightness down to the lowest readable setting I can't manage to break a full hour. Nothing on in the background, WiFi/bluetooth radio off, anti-virus off, and so on.
Thats a good rule of thumb for Ni-Cd or NiMH batteries but that will destroy lithium based batteries pretty quick.
The laptop isn't even a full year old yet so I'm pretty sure it's safe to assume it's a Lithium based battery. Not sure if it's lithium polymer or lithium ion though. Was hoping for some feedback from the local Linux fanatic but it seems we don't have one.
Obviously, no temptation to run 3D stuff due to it not even being possible would help, but the main problem is that you need a driver that properly powers down (parts of) the card whenever possible. I'm actually sticking with ATI's crappy official driver blob just because of this - the open source ones really suck at powersaving. No idea if the situation's better with an nVidia card.
I have an Envy 15, with the same cpu as you but with the ATI 5830 gpu, and only manage to squeeze 1hr 30mins fom the standard battery, just browsing the web. My best solutions to date, (if you wanna stay with Windows) were to underclock the video card, reduce screen brightness to 50% or lower if you can bear it, and turn off bluetooth. With this i can just scrape 2 hours.. But luckily i have an extra battery.. or i just cheat and use my battery sipping Mac. Just out of interest, how many processes are you running? By this i mean is all the standard HP bloatware keeping you cpu busy, thus reducing your battery even further.. If so i suggest a fresh install to blitz all the bloat.. Just checked mine and im running 49 processes. Win7X64.
Yeah, reduced brightness is a big power saver. I'm comparing apples with oranges here, but your standard Android phone (I'm using these as an example just because they offer kinda detailed statistics on this) uses around 60% of its energy just for the display. IIRC Windoze has some "Background Indexing Service" (not sure if it defaults to "on") which keeps looking at stuff all over your HD. Check if it's active, if so, kill it. Same goes for disk defraggers. The goal of this exercise is to allow the HD to spin down. Generally speaking, go for everything that keeps your hardware busy first, then CPU intensive stuff second. If you're really desperate, think about removing any optical drives and/or one of the HDs. Better yet, run your system off a SSD (or, significantly cheaper, a simple thumbdrive, or maybe an SD card or whatever).
I do turn the brightness down as low as it can go without being unable to read anything on the screen. As for processes I usually have about 60 and as much as I have tried I can't seem to get that number down without disabling anti-virus and a bunch of services that I'd just have to re-enable after I was done taking notes. An inconvenience that negates the whole point.
Have you removed as much of the bundled HP crapware as you can? I know it might seem extreme, cos i dont know if your used to re-installing OS's, but a clean install of win7 on my envy not only cut my processes down a lot, but i also get a bonus reduction in heat, because its not so busy churning over all the useless HP crap, which in turn gives me a boost in battery life!! If you do decide to re-install, dont forget to back up your drivers from your HPsetup folder, just in case. The best way i found to see if programs or HP stuff is keeping your cpu busy, is to quit all your programs and open Windows task manager, to see what you CPU is doing, if its constantly jumping up or is staying above 1 or 2% for more than a second when idle... something is wasting your battery.. Our cpu's are very responsive, but also very power hungry, an I7 720qm is rated at 35 watts!! and my standard battery is only 55Mwh, so keeping it doing only the things you want is the way to go.
Yes removing as much of that bloatware is the first thing on my list of things to do whenever I get a laptop fresh from the factory. I'd prefer to do a fresh install but leaving the OS on there as it came is not only easier but allowed me to make restore discs which it didn't come with as I didn't feel like paying a $10 premium for some pre-pressed DVDs. I did install XP to the secondary harddrive and turned off almost every service I knew I could that wouldn't affect anything I absolutely had to have as well as stripping down everything that ran at boot that I didn't need (seriously nVidia, I don't need your logo down there. Same goes for you IDT). Got about 2 hours of it just sitting there idling which is about as close to sitting there typing up notes as I could simulate without actually typing up notes. Still had plenty of life left when I called it quits as to not risk damage to the battery. Assuming the nVidia driver for Linux has features for power saving this might actually be quite useful as well as giving me an excuse to play with all of the network security tools Linux has to offer.
Are there any over/underclocking utils for your gpu? our cpu disables the turbo boost when you unplug the mains power, keeping itself underclocked!! If you could underclock your graphics card too it would give you a boost in battery time, although if you try to do anything that needs the gpu at full speed it will probably crap out and freeze.. i know mine does. should be fine for basic browsing and typing. I take it your laptop doesn't have discreet graphics and relies on the sole gpu like mine? As for linux, it wont run on my envy.. It wont or cant recognise the thermal zones and my cpu/gpu fans are non functional.. Sorry. Its win7 or nothing for me..
