Raddichio and I have the same phone, a V551. I use mine if there's a chance it'll get damaged or "found". Paying $30 to replace it would be a ripoff.
As far as the OP, I have something going on in Tasker at the moment that messes up my screen off time (normally 30 seconds), so when it doesn't turn off I reboot. If it may drop below 40% battery during the night, but it's too high to charge when I go to sleep, I turn it off. Otherwise, it just sits thare. (Oh, and I reboot to switch ROMs when I need to run a different one.)
Charging? Qi, and the battery doesn't get hot enough to shorten its life, so when it drops to near 40% it goes on the charging plate, even if I'm not going to be able to take it off for 12 hours. Treated the V551 batteries the same way, and I'm still using the ones I took out of the package in late 2004.
(If we're trying to outdo each other with old phones, I still have a couple of MicroTACs - vintage 1989. One still has a working - but too working - battery. But it's an unfair fight - I was a dealer.)