If I'm at work and want to listen to music can I plug the unit into a wall charger and hypothetically it won't use battery power cycles that will reduce the lifespan of the battery?
If I'm at work and want to listen to music can I plug the unit into a wall charger and hypothetically it won't use battery power cycles that will reduce the lifespan of the battery?
Using your phone while plugged in will not reduce the life of your battery. Try to pug it into a high capacity "Wall Wart" charger. If you plug it into a USB port, the phone might draw more current than the USB port can supply. If that happens, your battery will slowly discharge.
Modern Li-ion polymer batteries like that in the Nexus 4 have pretty good charge life cycles. You'll likely replace the phone before it becomes necessary to replace the battery due to charge cycle exhaustion. I wouldn't recommend draining and charging it several times a day, but if you want to use it while plugged in to a wall socket it should not significantly affect overall battery life.