My Raphael is dying...

I've never really had great battery life with any mobile phone. However, I imagine that you can gain a few hours/minutes by disabling the background data. I usually charge up my phone over night and it lasts till I put it back on the charger. However, I have run it down to about 10% a few times.

I don't know what else to tell you. It does seem rather odd but if you are just going to get another phone anyway, I'd try to tough it out till then. Do you remember exactly when you noticed this behavior? Has anything changed during that time?

Is your battery swollen in any way? If it is, that could be the cause of bad battery life.

Come to think of it, one of my batteries seem slightly swollen and even though it is the oldest of my three batteries, it still works on occasion (when I use it). Now on the other hand, I don't constantly charge my phone via laptop. I hearsay, that doing this somehow *may* change the lifespan (possibly behavior?) of the battery. I can't say for certain as I don't usually charge my phone in this manner. Additionally, I try not to continuously charge my battery to 100% (rather 80% is what I look for) and I also try wait till my battery is at least 30% before I put it on the charger. I have read that this is the "optimal way" to charge and discharge your battery (or li-ion batteries anyway).
Perhaps you can try to do this and tell if there is a difference? I almost want to say that even through this, there is a slight chance that you'll notice an increase of battery life but perhaps, it'll be more consistent instead of the rapid discharge. Also, this could be a telltale sign that your battery is on its way out? You might want to keep that USB cord handy in the meantime and try to keep the battery levels between 80 and 30%.

Ah, I forgot you were using a stock ROM and not a custom ROM. So, what do you see when you tap the battery icon/top curtain?