M2 cards and battery power

[Mike Fishcake]

Coming from a self-confessed computer geek, this is the sort of question I'm a bit embarrassed to ask, because I feel like I should know the answer.

ANYWAY...

Someone I know is convinced that a higher capacity M2 card (say for example a SanDisk 4GB card) drains far, far more battery life on a Sony Ericsson phone than a standard Sony 512MB M2 card. True? False? True to a certain extent but not something worth worrying about?

[Ferral]

Its everything else running that drains the battery. Things like GPS, Wi Fi (Both depending on specific models), Bluetooth, 3G, vibrate alerts etc

If they have a battery that is draining quickly it could be down to a faulty or dying battery or even some sort of software bug. Size of the memory card is irrelevant as it is not something that is being constantly scanned and accessed which would drain a battery (kind of like a laptops hard disk constantly being accessed will drain the battery pretty quick).

Secondly when charging batteries on mobiles its best to actually turn them off and do it over night or you won't get a full charge. This conditions the battery as well as helps it hold onto the charge. Samsungs are notorious for this as the screen lights up and doesn't go off when charging (even when switched off) so you never get a full charge.

[Templar87]

Agree with everything above. If the card isn't being read/written to/from then it shouldn't use any battery anyway - if it does it would be very very little. Size would be irrelevant in either case - has the person you know done a test to compare two different cards?

[Mike Fishcake]

It's kinda what I was thinking, but with me never having a card-upgradeable phone before (shocking! :-o), I didn't have anything to compare it against.

A "test" has apparently been done, but I suspect it wasn't done under lab conditions

[Funkstar]

I'm sure a larger card would use more power, personally doubt ths would be noticable.

There are far more power hungry components in the phone that a memory chip. Screen, radio, processor, etc.

Is there any way to report the power sonsumption of a USB port?

You could test it on a PC with one card in a reader then the other card.

EDIT: of course there is. Device Manager -> Universal Serial Bus Controllers -> then open up each of the Root Hubs and Generic Hubs to see the power draw of each device attached

EDIT2: Although it may just report as being 500mA regardless. My microSD in a card reader apparently uses 500mA. I don't think so. A laptop hard drive uses that.

[Templar87]

It's kinda what I was thinking, but with me never having a card-upgradeable phone before (shocking! :-o), I didn't have anything to compare it against.

A "test" has apparently been done, but I suspect it wasn't done under lab conditions

This test sounds pretty dubious indeed :-P

I'm sure a larger card would use more power, personally doubt ths would be noticable.

After the phone has recognised the card after it's plugged in (probably just checking the first few blocks of it to detect the file system), there shouldn't be a reason for it to use any power on the card. M2 cards don't require power to maintain their state (clearly, as you can take them out of the phone and get your data back) so it shouldn't matter what size the card is, right? Or have I missed something?

[Mike Fishcake]

Don't think you've missed anything - I just wanted to confirm that the claim wasn't legitimate