Asus EeePC 900 Battery Life
These are real-world tests. I didn’t use any burning software, but instead did my usual day-to-day work, which involves Gmail, reading via my feedreader (Bloglines Beta), reading up various blogs, and also posting on blogs. And as such, being a real-world test, this involved some pauses in between for bathroom breaks, snacks, and such. And so you would notice a few minutes of “sleep” time in between, where I would close the Eee’s lid to save power.
This was done on an EeePC 900 12GB running (the OEM) Windows XP, updated to SP3. Brightness was at 30%, with WiFi on and audio muted. Note that I had turned off wired LAN in my BIOS, since I didn’t need to get wired, anyway. Camera was also turned off via EeePC tray utility.
Battery is the stock 4-cell battery rated at 7.2V, 5800 mAh.
Here are the results:
2:39 p.m. - Cold boot. Windows usually takes about 30 seconds to launch and another 25 seconds until SSD reads stop.
2:46 p.m. - Sleep. Sudden torrential downpour. And we have laundry hanging outside. And so I had to run out to bring the clothes under cover. Sigh. That’s working at home for you!
Uptime: 7 minutes.
2:59 p.m. - Wake up. Back to work. Am at my desk now, so I’m actually working on my bigger laptop at the same time.
3:31 p.m. - Auto sleep. Read a pretty long email on the bigger laptop, so I somehow left the Eee idle for 5 minuets–which is the idle time I’ve set Windows power management to put the machine to sleep.
Uptime: 32 minutes.
3:39 p.m. - Wake up. It’s a battery test, after all, so I’ve turned the Eee back on again to do some reading up on relevant forums.
4:37 p.m. - Sleep. The Eee actually spent another 5 minutse idle. Damn those long emails.
Uptime: 58 minutes
4:39 - Wake up. 5:55 p.m. - Sleep. No more rain. Brought clothes back out. Not that there’s any sunlight to help dry them faster, but it’s something one has to do.
Uptime: 76 minutes.
6:06 p.m. - Wake up. Battery meter is saying I only have less than an hour left.
6:23 p.m. - Battery LED is flashing LED.
6:32 p.m. - Windows is giving the critical battery alert. I figure I could still do a post, and I publish an article I’ve been writing on Blogging Pro.
6:39 p.m. - Power down.
Uptime: 33 minutes.
And so adding all those uptime minutes, we come to a round sum of 206 minutes. This translates to 3 hours and 26 minutes or roughly 3 and a half hours.
Strangely, that’s exactly how long BatStats estimated the 5800 mAH Asus battery to last.
EeePC 900 Picky with RAM Modules
As reported on the EeeUser forum, the EeePC 900 is somewhat picky with RAM upgrades. If the RAM chip is not exactly spec’d like the stock RAM module, then the computer would be prone to freezing, especially when switching between battery and mains power.
And so I tried upgrading my EeePC 900 with a 2GB Kingston memory chip that I currently use on my Compaq B1200. It’s a PC2-5300 CL5 200-pin SODIMM with part number 9905295-052.AH0LF and serial number 900FE501.
I booted up fine on battery power, but when I plugged in the mains adaptor the screen garbled up.
I next tried an Apacer 1GB module with part number CS.01G2A.C00 thinking that it was supposed to be similar (it’s 1GB, after all). The system boots up fine both on battery and mains power. But when you switch from battery to mains, the system just freezes.
And then lastly I tried a Kingston 1GB module with part number 9905295-015.A00LF, and it’s the same with the Apacer chip.
The issue seems to be with running on “high performance mode,” which essentially means at a clock speed of 900 MHz. The EeePC 900 clocks down to 630 MHz when running on battery, to extend battery life. The system then goes back up to 900 MHz when plugged in, so the system is faster. This is with latter BIOS versions. In the earlier BIOS releases, the change is not dynamic. You have to select either power saving or high performance option in the BIOS, and the speed is static at either 630 MHz or 900 MHz.
Note that all of these above RAM modules worked fine on my 701.
Also, note that the RAM module that came with the EeePC 900 is an AData PC2-3200 (running at 400 MHz) with part number DOGC1A08342. I find it strange that the chip is a 400 MHz one. Even the original 512MB chip that came with my EeePC 701 was a 667 MHz one!
This means if you plan to upgrade your 900’s RAM, better make sure the module is compatible!
Asus EeePC 900 Battery Drain Woes
A thread on the EeeUser forum details how some (or most?) EeePC 900 units drain battery even when turned off.
I was just wondering if anyone else has been having this same problem. Now when my eee pc 900 is fully charged and i leave it for a couple of days not using it the battery still drains when even not in use.
And I agree that this is a serious reliability issue. For many people, the Eee serves as a mobile work machine, and for some, as a travel companion. Some just turn on their Eee for a few minutes to check on email and read news, and then off again. But if you lose 10% to 20% of your charge each day then you’d have to plug it in often, which beats the purpose of having a portable computer with a three-plus hours battery life.
I have yet to test this on my machine, but I’m curious to know how Asus will deal with this. Is this perhaps just a BIOS issue? Or is this a battery issue?
