I've kept an eye on all the threads about battery usage and charging routines and I have some observations!
Some of you are cycling your batteries. Don't!
Some of you are conditioning your batteries. Don't!
Some of you are discharging your batteries. Don't!
Why? Well, contrary to one poster who said it makes no difference, it harms the Lithium Ion chemistry!
They don't like being discharged below a certain point. Do it too often and they won't recover!
They don't like a widely fluctuating charging band! This will hasten the reduction in capacity!
They don't like being overheated (although their operating temp range is quite broad!). And strangely they don't like it too cold.
They have a finite shelf life which starts from the day they are manufactured and their condition from then degrades to the point where they fail!
This is not to be confused with their charge holding abilities which are very good for their full life! When they go they just go!
Additional problems associated with low discharge is that they need the extra ooomph to get them charging again, but each discharge takes a little bit more out of them! That's why 500mA USB ports have trouble from "flat" and why the charger supplied is 800mA!
So what should you do?
Well, all the above is well documented as Lithium Ion battery characteristics, but, I haven't been able to find one example of an authoritative guide to charging! I heard ideas about doing it with the phone switched off or on standby or by so many hours, etc, but nothing was backed up by any reasoning.
Now, we all use our phones in different ways, but, the one thing we all need is max power so any method of gaining power should apply to us all.
I have run some tests on three N95s all purchased at the same time and all with batteries of approx the same age and they have had approx the same usage. I have charged each of three in different ways-
A. Was charged only every night (approx 6 hours) and nothing during the day, for a week.
B. Was charged when it went flat.
C. Was charged at every opportunity, day and night.
After the week, at the next opportunity when the phones all had an end of charge fall together, they were all unplugged and left without any use at all.
A, lasted for 50.5 hours.
B, lasted for 22 hours.
C, lasted for 58 hours.
That's a huge difference and could go part way to explaining why some people have different experiences with the battery.
All phones are approx 4 months old and all have the same batch no. on the battery.
Something I did notice was that phone B got hotter as it got closer to failing. This could be it's attempt to wring out the last drops, I don't honestly know!
The coolest in operation (subjectively) was phone C.
Also when the phones were next charged (to battery full) the quickest in order were C, A, B. None of the phones were switched off, when on charge, as, for this I would have to have a fourth phone so this was beyond the scope of this test, but, I intend to try a head to head with two phones over night for a week!
More experiments are needed so I would ask others to do similar tests!