Hi Scott:
The major areas of safety of battery-operated
product are:
1) the discharge circuits;
2) the charge circuits;
3) the chemical process during discharge;
4) the chemical process during charge.
The circuits must be designed such that the
chemical processes are not stressed.
However, once the chemical process is stressed
and results in damage to the separator, then
there is nothing that can be done via the
circuits to control the resulting chemical
reaction; the energy must be expended.
The "safe-ness" depends on the RATE the
chemical energy is expended. A high rate may
result in an explosion; a low rate may result
in mild over-heating.
World-wide, many standards organizations are
addressing circuit requirements that will not
stress the chemical process.
Battery manufacturers are honing their processes
to make the batteries (the chemical processes)
less susceptible to physical, thermal, and
electrical stresses.
With the exception of high-impedance keep-alive
button batteries, there is hardly a battery
that will not overheat during excessive
discharge rate or excessive charge rate. Even
alkaline batteries have been known to start a
fire when discharged at too high a rate.
The only answer I can give is to follow the
standards development, and apply the latest
and greatest drafts -- even though they are
not yet standards.
Best regards,
Rich
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf
> Of Scott Xe
> Sent: Thursday, July 09, 2009 7:38 AM
> To: [email protected]
> Subject: How to determine if battery-operated product is safe or not
>
>
> We have an USB rechargeable battery-operated video clip/MP3
> player. As battery-operated products do not fall into LVD
> directive, what can we apply the basis to determine the
> product safe or not? Looking at historical safety hazard
> reports on the market, there was not much any recall on this
> type of products except the explosion of rechargeable battery
> pack. However, the possible explosion of rechargeable battery
> pack cannot be picked up by LVD directive or dedicated
> UL1642/2054 battery cell/pack standards. Otherwise, Sony did
> not need to recall millions of battery packs and the said
> standards are not required the review. What is potential
> hazard do we need to look at this type of products? As the
> safety hazard is tied with power energy, is there any
> reference that there is no safety concern if the power energy
> is below certain level?
>
> Thanks,
>
> Scott
>
>
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