Click here to get back home

27 W/hr-battery, means 7 hr notebook life?
 Home | NewsGroups | Search | About
Login Password
Register Now! Lost Password?
 comp.sys.laptops    Post an article   get this group's latest topics as an RSS feed add this group's latest topics to your My MSN content add this group's latest topics to your My Yahoo content
Subject Author Date
27 W/hr-battery, means 7 hr notebook life? Jan 04-02-2005
Get Chitika Premium
Posted by Jan on April 2, 2005, 8:41 am
Please log in for more thread options
 I see that Dell's new X1 notebook has a 3-cell 27 W/hr-battery. If I
assume voltage is 15v and current is 4A, then it consumes 15/4=3.75W.

27/3.75= 7.2 hrs. I guess this can't be actual battery time?



Posted by AndrewJ on April 2, 2005, 2:17 pm
Please log in for more thread options

>I see that Dell's new X1 notebook has a 3-cell 27 W/hr-battery. If I
>assume voltage is 15v and current is 4A, then it consumes 15/4=3.75W.
>
>27/3.75= 7.2 hrs. I guess this can't be actual battery time?

Sounds about right. Since it's really just a Samsung Q30, i would skip
the middleman and save yourself some nightmares.

http://www.engadget.com/entry/1234000913038231/

--------
AJ


Posted by Quaoar on April 2, 2005, 4:58 pm
Please log in for more thread options
Jan wrote:
> I see that Dell's new X1 notebook has a 3-cell 27 W/hr-battery. If I
> assume voltage is 15v and current is 4A, then it consumes 15/4=3.75W.
>
> 27/3.75= 7.2 hrs. I guess this can't be actual battery time?

Power = volts * amps. P = 15*4 = 60 watts. Energy = Power * time : time
= energy/power = 27 watt-hr/60 watt = 0.45 hours. This doesn't fly
since the assumption of 4amps continuous load is wrong and the 15 volts
could well be only the overvoltage required for battery charging.

You really have to work this the other way around on the basis of a
total system work cycle, taking into account the performance
characteristics of each device on the system: hd, optical drive,
display, cpu, ram, etc for a schedule of user functions on the laptop.

Q




Posted by dg1261 on April 2, 2005, 10:29 pm
Please log in for more thread options

> If I assume voltage is 15v and current is 4A, then it consumes 15/4=3.75W.

Huh?




Posted by Gary Helfert on April 3, 2005, 3:45 am
Please log in for more thread options
Without doing the math a 27 Watt hour battery would run your laptop about 1
hour.

>I see that Dell's new X1 notebook has a 3-cell 27 W/hr-battery. If I
> assume voltage is 15v and current is 4A, then it consumes 15/4=3.75W.
>
> 27/3.75= 7.2 hrs. I guess this can't be actual battery time?
>




Similar ThreadsPosted
Breathe new life into an older notebook with a few upgrades? January 8, 2006, 10:22 pm
PC Card - Cardbus 'supported' means? August 16, 2005, 7:36 am
Battery life? ? ? May 9, 2005, 11:53 pm
eternal life October 30, 2006, 9:04 am
HP Battery Life February 8, 2007, 7:32 pm
Healthy life May 8, 2008, 4:13 am
AMD M processor battery life July 28, 2004, 7:11 pm
Laptop - battery life February 1, 2006, 6:19 am
Mac Laptop Battery Life July 29, 2006, 2:38 pm
Li-Ion Shelf Life: Outdated? August 27, 2006, 10:42 pm

Our other projects:

Art Dolls, Fairies and Mermaids - Sunnyfaces.net

Roy's Linux, Programming and Search Engines messages

1-Script XML SitemapXML Sitemap