Hi there,

I want to know why it is that both my PDA (A Compaq iPAQ 3630) and my
digital camera (Canon Powershot S30) both manage to use up batteries
while being turned off!

I've just had to restore my data to the iPAQ after having it turned
off for a few days, and when I came to use the camera the other day
the battery was shot after being turned off for a few weeks. Is this a
design flaw? Is there a fundamental reason why these devices need to
draw power despite being turned off (Like a TV in Standby mode) - or
do I just have rubbish products? (In terms of battery life anyway)

Any information that clarifies what is going on, and if there is
anything I can do about it appreciated.

Cheers

Dave

Hello,

The basic reason that your PDA uses batteries when it is off is
that it stores your data in volatile RAM when the device is "off."
Unlike a desktop or laptop computer, these devices don't have a
hard disk which can retain its data in the absence of electricity.
Instead, they use memory chips which have to be constantly
refreshed to prevent them from forgetting what they "know".

Here is a Usenet article which answers your question regarding the
iPAQ, and mentions software alarms as an additional possible cause
for the iPAQ's battery consumption:

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=u%24PC9dQdBHA.2172%40tkmsftngp03

While the iPAQ's battery usage is normal, your Powershot S30
stores its data on CompactFlash memory cards, which do not require
power to retain their memory.  I couldn't find any reference to
this problem on the web, so I called Canon technical support
(1-800-652-2666) and told them about your problem. The man I
talked to was very helpful, and said that the Powershot should not
be draining batteries when turned off, and that you should have it
serviced in order to fix the problem.

You mentioned that the Powershot sat idle for several weeks.  All
batteries will eventually loose their charge when left for a long
enough period of time.  Depending on how long the camera was
unused, and the condition of the batteries, it is possible that
the batteries simply "expired".  If the batteries are not
rechargeable, it might be worth checking the expiration date on
them.


Additional Links:

Howstuffworks "How Flash Memory Works"
http://www.howstuffworks.com/flash-memory.htm

Howstuffworks "How RAM works"
http://www.howstuffworks.com/ram.htm


Search Strategy:

Google Groups search: ipaq "battery life" OR "battery usage" off
http://groups.google.com/groups?hl=en&lr=&ie=ISO-8859-1&q=ipaq+%22battery+life%22+OR+%22battery+usage%22+off&btnG=Google+Search

(I performed additional searches for information on the Powershot,
but they were fruitless so I haven't included them here.)


I hope I've answered your question satisfactorily,
bikerman-ga

Hi Bikerman,

Thanks for the answer - useful info. The reason for the 3 stars (As
opposed to higher) is that I think your answer on the Powershot could
have been better. I used your Google search string and replaced 'ipaq'
with 'canon s30' and found several threads about the way in which
Canon batteries self discharge - which suggests that the camera is
fine, and it's an inevitable consequence of the type of batteries
Canon uses to power the camera.

I am surprised you didn't find these threads!

Cheers

Dave

On niggly point of the Canon S series they don't have a separate back
up battery for the date and other settings, so if  your lithium
rechargable is flat for about 2 weeks or more the camera forgets it's
settings. Though I haven't  yet left my camera uncharged that long.
(info from manual of S45).
The more recharge and discharge cycles your battery has gone through
the less capacity it is able to store, and at 200 recharges Canon
recommends you get a new battery. Overcharging also kills the battery
and the Canon (S45) manual highlights this point. Temperature also
affects the ability of the battery to retain charge, generally colder
temperatures discharge the battery faster.
regards lot-ga