AC/Battery Question
Discussion
If my laptop battery lasts an hour and I wanted to use if for exactly two hours, which would use less electricity?
i) Leaving it on AC power from the start
ii) Using all of the battery power first and then switching to AC for the rest of the time
It seems like it should be (ii) but as you are both charging the battery and powering the computer does it even itself out?
i) Leaving it on AC power from the start
ii) Using all of the battery power first and then switching to AC for the rest of the time
It seems like it should be (ii) but as you are both charging the battery and powering the computer does it even itself out?
Leaving it on AC with a full battery should reduce its power consumption. If you plug something in to a laptop's AC connector (even if it's a long-run battery pack) the laptop will think it's on full mains and start trying to charge its battery.
Alternatively if your using Windows then when the battery gives out, hibernate the laptop, remove the battery pack from the PC, plug in AC adaptor and power on.
No battery pack = no charging.
Alternatively if your using Windows then when the battery gives out, hibernate the laptop, remove the battery pack from the PC, plug in AC adaptor and power on.
No battery pack = no charging.
road2ruin said:
Love to know why you need to know this answer? Technically speaking the best way would be to remove the battery and then run from the mains the whole time. Not sure if your machine will let you do this but it might.
It was just a thought I had, as I have a laptop at work which I rarely use on battery. I wondered if I continually ran down the battery and then charged it back up, rather than staying on AC all the time if it would raise or lower the total electricity usage. If you see what I mean?!
I'd say use it on AC for one hour, then unplug the AC and drain the battery. Otherwise if you drain the battery first then you're both powering the laptop and charging the battery during the second hour, and for the purposes of this question it doesnt seem to matter if the battery is charged or not at the end of the experiment.
If you're counting electrical power used as including power used from the battery, I'd still say do it that way as laptops often lower the brightness of the screen and slow the CPU when not on mains, which would mean less power used overall.
The battery will have a longer life if its 'excersised' from time to time too.
If you're counting electrical power used as including power used from the battery, I'd still say do it that way as laptops often lower the brightness of the screen and slow the CPU when not on mains, which would mean less power used overall.
The battery will have a longer life if its 'excersised' from time to time too.
Edited by sneakyneil on Tuesday 12th December 15:51
exactly as sneakyneil says as when running on batteries it's tries to save power by reducing brightness and slowing the CPU.
if you're that bothered you can install power saving features and reduce the cpu speed/brighness manually.
what you should be more concerned about from a cost point of view is screwing up you LiIon battery by draining it completely and then recharging as it's reduce the life and amount of charge it can store and that costs money to replace. also depends how much you need your CPU power while you work!
I've always wondered if a cup of tea will cool quicker exposed to the air or with my hands clasping it. I think it will cool quicker in the hands, even though the hands represent a smaller heat gradient; the air is a much worse conductor of heat.
if you're that bothered you can install power saving features and reduce the cpu speed/brighness manually.
what you should be more concerned about from a cost point of view is screwing up you LiIon battery by draining it completely and then recharging as it's reduce the life and amount of charge it can store and that costs money to replace. also depends how much you need your CPU power while you work!
I've always wondered if a cup of tea will cool quicker exposed to the air or with my hands clasping it. I think it will cool quicker in the hands, even though the hands represent a smaller heat gradient; the air is a much worse conductor of heat.
madras said:
what you should be more concerned about from a cost point of view is screwing up you LiIon battery by draining it completely and then recharging as it's reduce the life and amount of charge it can store and that costs money to replace. also depends how much you need your CPU power while you work!
LiOn and Lithium-Polymer (i.e. laptops and ipods) battery packs will loose maximum charge capacity regardless of them being used or not; irrespective of it having being charged first. I believe it's around 10% per year, so a 10 year old LiOn pack will be dead (or have minimal storage abilities) even if it's been sat on a shelf it's whole life.
The best way to make a laptop use less power would be without it's battery pack installed and with utilities loaded that force the power management system to keep everything in 'battery mode'.
ThePassenger said:
madras said:
what you should be more concerned about from a cost point of view is screwing up you LiIon battery by draining it completely and then recharging as it's reduce the life and amount of charge it can store and that costs money to replace. also depends how much you need your CPU power while you work!
LiOn and Lithium-Polymer (i.e. laptops and ipods) battery packs will loose maximum charge capacity regardless of them being used or not; irrespective of it having being charged first. I believe it's around 10% per year, so a 10 year old LiOn pack will be dead (or have minimal storage abilities) even if it's been sat on a shelf it's whole life.
The best way to make a laptop use less power would be without it's battery pack installed and with utilities loaded that force the power management system to keep everything in 'battery mode'.
Spot on. Just use the mains as you lose a lot of power in the charge process through poor transformers (no, not robots in disguise) so why bother charging it if its never needed. Just use the power saving features to reduce the consumption of the machine while on mains.
Gassing Station | Computers, Gadgets & Stuff | Top of Page | What's New | My Stuff