which recharge?

Here’s an interesting observation I would have made this morning if I hadn’t been still working on what had kept me up so late last night (trying to get my novel edited and covered and online in time to order it today) right up until I left for work:

Last night I didn’t get to bed until a little after 3AM, and it was just before I lay down to sleep that I remembered to put my cellphone on its charger. When it woke me up a little after 6AM, it wasn’t finished charging yet, but I was expected to be. I left it, and myself, snoozing for an extra half hour or so, but then we both had to go face the day – full charge or not.

Now, I got through the day fine on the amount of charge I got; look at me, still going after midnight. But my phone spent the whole day at three bars. I’ve got it on the charger again. On a full charge, it can go over eight days without another nap, since I upgraded its battery. Where can I get an upgrade for myself to go eight days without a recharge?