On Wed, 16 Nov 2005 15:43:02 GMT, dave wrote:

Just took a 'mo to actually read an addendum sticker in my mp3 players "manual".
It says "leaving the battery in place while using the player connected to the
computer for a long time could lead to dammage or explosion of the battery"! It
does not define what a "long tome" is.

The battery is an alkaline (ie non-rechargable) aaa. I *guess* this warning is
because it is a non-rechargable battery , and somehow gets charging current to
it in some way from the computer usb port? I know when connected to the
computer, the player does indeed get it power from the usb port.

Would the "problem" go away if I simply used a rechargable battery in there? (Or
would that damamge the player?)
Thanks

Simple enough. Leave it plugged in and check the temperature of the
battery at intervals. It will have to be pretty hot to "explode".

Problem with rechargables is they are a slightly lower voltage and
have almost no internal resistance, so can damage cheaper circuitry,
unless designed for them.

Having said that I have always used them even when it said not.

EricP wrote:

Problem with rechargables is they are a slightly lower voltage and
have almost no internal resistance, so can damage cheaper circuitry,
unless designed for them.

Having said that I have always used them even when it said not.

Me too; loads of times, in loads of gadgets, and I have never to my
knowledge suffered damaged circuitry or an explosion.

David

EricP wrote:
Simple enough. Leave it plugged in and check the temperature of the
battery at intervals. It will have to be pretty hot to "explode".

Problem with rechargables is they are a slightly lower voltage and
have almost no internal resistance, so can damage cheaper circuitry,
unless designed for them.

Having said that I have always used them even when it said not.

Me Too. /AOL
MY MP3 player (MSI megastick) runs fine on a NiMH AAA, for almost as
long as it's supposed to on an alkaline. No charging current on USB
though AFAIK - a test may be in order tomorrow in work as I can stick a
thermocouple in there.

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dave wrote:
On Wed, 16 Nov 2005 20:00:41 GMT, Chris Hodges wrote:

EricP wrote:
Simple enough. Leave it plugged in and check the temperature of the
battery at intervals. It will have to be pretty hot to "explode".

Problem with rechargables is they are a slightly lower voltage and
have almost no internal resistance, so can damage cheaper circuitry,
unless designed for them.

Having said that I have always used them even when it said not.

Me Too. /AOL
MY MP3 player (MSI megastick) runs fine on a NiMH AAA, for almost as
long as it's supposed to on an alkaline. No charging current on USB
though AFAIK - a test may be in order tomorrow in work as I can stick a
thermocouple in there.

Mmm if there's no "charging" current, where does the energy come from in any
*possible* explosion I wonder. I very much doubt that even if an AAA was
short-circuited for hours it would explode.

There are too many layers.
The guy that actually designed it.
His manager.
The people that actually constructed it, probably with some substitutions.
The manual writers.
Marketing.
The translators.

Eventually, it can get far enough from the guy that designed it that the
actual manual text bears little relation to reality.
This can especially be the case with some MP3 players that the firm that
puts it together may not have actually done the design, but just be
using a standard circuit published by the maker, with the only 'innovation'
being in the paint colour.

Chris Hodges wrote:
Me Too. /AOL
MY MP3 player (MSI megastick) runs fine on a NiMH AAA, for almost as
long as it's supposed to on an alkaline. No charging current on USB
though AFAIK - a test may be in order tomorrow in work as I can stick a
thermocouple in there.

I checked this out on mine yesterday. It turned out to be a more
thorough test than I thought as the battery was flat to start with. The
temperature in the battery compartment reached 25 degC (ambient was
20-21), however the battery did not charge enough to switch the player
on even briefly after 3 hours. On this model you have to plug it in to
the USB and then press the button before it works in memory stick mode.

Chris


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