How improve Battery lifespan iPhone 5

Hello all,

I google it a bit, but couldnt find a straigh answer

Here is my situation. I dont use my iphone 5 very often, maybe 1 call a day, some email checking and/or some messages here and there. Battery is usually out in 2 days.

I know apple suggest to leave it drain once a month but ....my question basically is:

May i charge my phone on everyday basis without killing the battery lifespan? (lets say, come to work and leave it charging while on the computer?)

Or will this be too much? should i wait until the battery is 10-20%? or even with a 60 is not an issue?

and guys, i know i can do whatever i want, im just asking what is better for my battery lifespan

Any comments would be appreciated

Vini