Re: TP750 Battery

[dewar@gnat.com (Robert Dewar)]

"> This is consistent with the problem I have had with my TP750 and
> batteries that are 2yrs old (1 yr use each). The 750 (dunno about the
> other models) would power cycle the batteries in the top 10% over and over
> again if you used it with the AC adaptor and the batt in by letting the
> battery wear down to the 90% mark and then charging it again.
> Unsuprisingly, it destroys the battery."


Of course a battery such as this in heavy use does not last long anyway.
Batteries are only guaranteed for a year, and that is because you cannot
expect them to last longer if you use them heavily.

The charge cycle quite likely decreases battery life, but for many people
it is important to be sure that the battery is fully charged when they
have been using the machine, even if this costs battery life, so this is
a quite deliberate decision by IBM, not an error.

If you are concerned about prolonging battery life, then you should not
store the battery in your machine while you are using it (I am a little
curious as to why you *do* store the battery in your machine if you
know it is troublesome, and have already destroyed batteries this way).

Basically only Lithium-Ion batteries can be handled without worrying
much about this sort of thing. Otherwise do NOT store a battery inside
your machine if you want maximum life.

So I don't see the 90% charge as destroying the battery, I see it as normal
use -- i.e. what is necessary to keep the battery charged and ready to go
at a moment's notice, which is what many users want.