So... who knows the answer...
Submitted: Wednesday, Jun 08, 2005 at 18:24
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Lone Wolf
... and it's NOT 42!!!
For those of you that take laptops out and about with you, and use them frequently whilst stationary, what sort of run time are you getting whilst the unit is plugged into an external 12 volt battery? I am not particularly interested in those that use a 240 volt inverter.... but those that use the likes of the kerio, etc.
I am under the impression, that my apple iBook, should be drawing around 1 a/h, whilst under normal use, like word processing, and up to 2 if I'm watching a DVD.
Anyone got any clues?
Cheers
Wolfie
Reply By: KiwiAngler - Wednesday, Jun 08, 2005 at 19:38
Wednesday, Jun 08, 2005 at 19:38
I find if the puter is basically 'just sitting there' then I get a few hours out of the on board battery. Which is a 14.8v 4400 mAH lithium ion battery.
If I am running explorer and using realtime mapping I get about 2 hours out of it.
I usually get about 1 1/2 DVDs.
If I connect to a power pack (12v Waeco 24Ah) I find it drains it very quickly.
I use one of these when driving and it keeps the puter battery fully charged no matter what the puter is running
http://www.vanson.com.hk/details/p3050.html
No electrician or puter geek...what I have written is what it is
AnswerID:
114940
Follow Up By: Lone Wolf - Wednesday, Jun 08, 2005 at 19:54
Wednesday, Jun 08, 2005 at 19:54
Now... we are getting somewhere...
I have ascertained that my battery is a 14.4 @ 4000 mah... which, allowing for the rported 6 hrs. general use, makes for a consumption figure of around 0.8 A/h @ 12 volts.
Now, it is interesting that you say the Outback, which I also have, drains quickly. So, it doesn't run the system for 24 hrs.
Bugger!
The best I can come up with, is a trickle charge 20 watt panel, which will maybe not keep up.......
Bugger!
I shall now look towards plan "B".......
Oh, by the way, it's for data logging in the bush, tied in with my Canon Camera.
Cheers
Wolfie
FollowupID:
370721
Follow Up By: KiwiAngler - Wednesday, Jun 08, 2005 at 20:07
Wednesday, Jun 08, 2005 at 20:07
I have never managed to get 6 hrs out of my puter on board battery even though 'mathematically' it should.
Get the notebook power pack that I use
http://www.vanson.com.hk/details/p3050.htm
it just saves all the hassles
I am guessing you also use Ozi with PhotoTool and merge the data with the photos?
Have you seen this?
http://homepages.tig.com.au/~robk/datalogger.html
FollowupID:
370724
Follow Up By: BenSpoon - Thursday, Jun 09, 2005 at 11:18
Thursday, Jun 09, 2005 at 11:18
Lone Wolf-
As Mike H mentined, when external power cuts out the lappys generally have features to cut down on their power usage... it may pay to invest in a timer relay that cycles on and off the power from the external batt pack- that way you still charge the batts, but use the power saving stuff in between. Generally when on battery the CPU slows itself a few cycles and panel brightness goes down. Also look at turning off any unused ports to save a little extra.
FollowupID:
370804
Reply By: geocacher (djcache) - Wednesday, Jun 08, 2005 at 23:17
Wednesday, Jun 08, 2005 at 23:17
Hi Wolfie,
The problem is that many if not all laptops run at quite high currents at a voltage higher than 12v.
Therefore you need a thing called a DC-DC converter to step the voltage up. This is the Kerio or similar device (
mine was from Jaycar and cost $89 and works just fine) which plugs into the cigarette lighter. The problem is that this conversion is not a particularly efficient process and an item that _Affordable_Storage_Drawers.aspx say 1 amp at 15 volts will require much more current at 12 volts to generate the lower current at a higher voltage.
My Toshiba power supply has an output of 5Amps at 15 volts and I would expect that my Jaycar DC-DC converter is using all of its stated 6 amp draw to generate that sort of current at that voltage. I can run some tests if you like.
AnswerID:
114983