Hello all, I have recently pulled out my blade cp from the garage and decided to get back into flying again. Unfortunately, when I'm flying, it has a hard time of getting above 5 feet, and the battery dies fairly quickly. I'm assuming that the battery has deteriorated over time, could this be correct? It has been sitting in my garage for over 4 years I believe. If so, what would a good replacement battery be that you all would recommend? Thanks!

EDIT:
Also, I have an aftermarket battery that I bought way back when and I'm not sure where I got it from. I don't have the manual or anything that came with it, but when I charge it, the charger starts blinking at some point. I'm assuming this means it's good to go? It's one of the 1100 mah li po batteries so I'm worried about overcharging it. If i'm under-charging it, however, then my problem described in the above paragraph could be an easy fix.