I've been running Ubuntu since Gutsy on an HP dv6308nr with dual AMD Turion 64 X2 TL-50s, 2GB RAM, and a 120GB hard drive with 4GB of that being swap. When I switched from Vista to Gutsy I noticed a decrease in battery life. But what's happened after doing a clean install of Hardy is just crazy. My battery only lasts 15-30 minutes.

What actually happens is that the battery drains by jumps of 10% every few minutes. Looking at the battery icon in the gnome upper panel shows, say 50% when I place the mouse over it. When I click on it, it often shows a reading 11 percents below that - 39%. And they always go up or down by ten.

When clicking on the battery icon to get more information, it says the Capacity is 5% (Poor)
Last full charge was 4.0Wh and the design charge is 75.5 Wh.

Clicking on the icon a day later, it told me the design charge was 69.5 Wh instead of 75.5 Wh. I don't know where Ubuntu is getting the design charge figure from, but obviously it should stay the same. So maybe it is misreading that.

Both times I installed Ubuntu, whether Gutsy or Hardy Heron, I got a popup on the first bootup saying the battery was not running or charging to capacity. When I installed Gutsy the computer was about 6 months old (it would get about an hour and a half to a charge) and now it's about 9 months old.

I have set cpu frequency scaling to powersave mode, I have laptop_mode enabled. I've used powertop and found that extra_timer_interrupt comes up higher than anything else when I'm not using the mouse or keyboard. (But I don't know if that's something I can work with or not)

Any ideas what I can do???

Jugney

UPDATE: I checked the hard drive temperature by typing sudo smartctl -d ata -a /dev/sda and it showed its temperature at 62 degrees Celsius, above the recommended temp for my hard drive. It's been sitting on my futon mattress, which tends to make the fan go on more, so I'm not sure what the normal temperature would be when it's on a desk. But that is pretty darn hot.

for one thing, if you dont treat batteries properly they can 'break' - it's called a memory effect.
how you should treat your battery is mostly documented in the laptops handbook and will often say that
you should use your battery until fully emtpy (or very close to), power off and charge until 100% full (do this like once a month)
also, when running on power for a longer period of time, care to remove the battery, or every so often, remove the power cable and use the battery.

if you battery is fine, yet is draining faster, theis could be due to things like wireless lan, bluetooth, not throtteling the cpu (or using 2 cores when only one is needed), keeping a cd/dvd in the drive (some drives tend to 'check' the bay every so often), no hdd spinn downs, any external devices (such as hdd's, keyboard, mouse, etc).

as for the temperature, yes - that is pretty high for a 2.5" hdd. standard warranty usually covers to 45 degrees, some 2.5" hdd's are designed for up to 60 degrees. but you will probably not get anything above that in standard laptops/devices.
check where your laptop fan is, and make sure you do not block it by standing it on the mattress.
some laptops have the fans located on the bottom and placing the laptop on a mattress in that case would not be a very wise thing to do.

It probably (?) gets the information from /proc filesystem, or that would be my lucky guess. You can see for yourself, read the files under /proc, like /proc/acpi/battery/... Maybe the acpi module isn't getting some things done correctly or something?

What if you turned acpi off, loaded the battery full and checked how long it lives - is it just false readings or something worse.

My laptop has the air intake on the bottom and gets quite hot if I use it on my lap. Time to find the little folding plastic table I bought years ago.

I think LiON and newer smart batteries are immune to the "memory" effect. The "memory" effect was entirely different anyway. It mainly affected NiCad batteries and was caused by recharging too much when not necessary. However, like most electronics, excessive heat or improper care can damage the cells inside the LiONs. If you have 5 cells and one goes bad you lose 20% of the capacity.

I damaged my battery in a Pavilion ze4315 by letting it lay in the carrying case while plugged into the wall. Even thought the top of the case was open, having the sides and bottom blocked by cushion allowed the heat to damage the battery. Ventilation is extremely important.

As mentioned, cd drives, wireless network connections and other peripherals will drain the battery faster. If your battery has the led monitor on the side, like mine does, check that to see if the reading coincides with what the os is reporting. Also try a livecd distro like Knoppix or Slax or Puppy to see what happens.

http://en.wikipedia.org/wiki/Lithium...n_battery_life
so - there you go :-P

ps. i dont trust wiki documents to be 100% correct, yet it will do here.