Charging "Consider replacing your battery"

I have had this Acer Aspire Laptop (Win7) for less than two years.
Yesterday it had an update session, after which I had to restart it 2 or 3 times, as the programs would not respond. Since that I had not shut down my computer.
(Not being plugged in right now)
This morning at 7:45 am I open it, do some school stuff, no problems, I close it again.
At 10 am I open it again, it says I "may need to replace battery" and "may shut down suddenly" (lets call this BR)
I close my laptop until I can plug it in.
11:30 am I plug it in, still says BR, I shut it off, take out the battery, put it back, plug it in, turn it on
nothing has changed
It's charging fine
What should I do? is there anything I can do besides replacing the battery?

The notification is now gone. I don't know how.
Once you get this BR message, does it go away only when you replace the battery?

I used to have a boss with a Compaq laptop. I don't remember the model, and this was long before Win7. I believe it was the early days of XP. Anyhow, he started having probs with his laptop's battery. The thing would only run for about 30 mins, then shut down due to low battery. He'd go ahead and hook it up to the power supply, wait about 15 mins, then boot it up and continue, tethered to the wall plug for the rest of the day. One day, in an effort to look impressive, I took his laptop, left him a maintenance tag, and took on the challenge of getting that Compaq to run straight.

My dad used to tell me that batteries develop memories. That is, before long, if, you didn't regularly let the battery get low before plugging it in, the battery tended to show "low" when, in all actuality, it still had 30, 40% of it's rating available. The way to reset the battery's memory was to boot the sys up to the login and leave it sit. Let it shut itself down. Continue to turn the sys on, and wait for it to shut down. (I did this for 4 hours!) Before long, the battery finds out where rock bottom is, in reality. Then, when the little LED light wouldn't even light up when you try to power up, plug the Pwr supply back in, and let the battery charge up to full without turning the system on.

I've heard that new batteries don't develop those memories anymore. But, I was a hero in the office that afternoon. He told me that later that week, the laptop ran on batteries for nearly 6 hrs before showing low batt warnings.

I just thought I'd share that. Don't know if it will help.