SPONSORED LINKS
"> 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.