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why, when my phone is fully charged does it lose charge just by turning it off? IE. the battery meter give you a full charge level, you turn it off, and some time later when you turn it back on the meter is only 2/3 full!
Quote from: paul.fr on 05/12/2007 14:36:29why, when my phone is fully charged does it lose charge just by turning it off? IE. the battery meter give you a full charge level, you turn it off, and some time later when you turn it back on the meter is only 2/3 full!There's possibly at least two factors here: - the battery may really be self-discharging - you may be seeing a fault/limitation of the method used to estimate the amount of charge-remaining.Batteries, especially rechargeables certainly do self-discharge; older NiCads were quite bad (self discharge in 4-3 weeks), newer NiMH better (a few months to self discharge at room temperature, I believe), I'm not sure how Li-Ion used in many mobiles fare. If cells are "old" then they may develop internal whiskers or other faults which accelerate their rate of self-discharge.It's not straightforward to gauge remaining battery capacity; parameters like the cell voltage depend not only on the state-of-charge, but also on the battery age and temperature. More sophisticated charge-indicators actually measure the current drawn from the battery and integrate it over time (I assume Sony's InfoLithium batteries used in digital cameras and camcorders do something like this).
= in this "modern" world many things are made to make us spend more money...Did you ask yourself why electronics technology has improved so much but batteries tecnology not?
On the contrary, batteries have improved enormously. NiCad technology of a decade ago gave us about 650mAh in one AA cell; modern NiMH of the same size give about 2500mAh. They are also cheaper in real terms. Li-Ion have an even greater charge (or capacity) to size and weight ratio.Half the problem is that modern gadgets (mobile phones with cameras and video-screens and mp3 players for example) keep upping other aspects of their "performance" and thereby increase their power demands to match.