Battery level indicator

[wes4bass]

I have an original Droid in which the battery would only last a couple of hours,,, and that was without using phone at all. I purchased a new battery, fully charged it, and the same thing occurred. After doing this several times, along with looking at battery usage, playing with checking and unchecking things, I discovered that if I turned off the phone and back on it would show up to 70 percent or so. After another couple of hours battery indicator would turn yellow, I would turn off/on and it would show around 50 percent. Now, if I didn't catch the battery indicator winding down to 5 percent, the phone would shut down and I would be unable to turn it back on without hooking up the charger. What is going on?