On the right is an old battery (around 4 years old) which shows that the last full charge was nearly 40% below the design capacity. From experience I know that this battery will only last a few months more. I've had a battery fail a few months after it tested 45% below its design capacity. I recently did a 'stress test' on this battery (which will show you the minimum time you can expect while running the laptop at 'full power'), and it only managed 36 minutes. Compare that with 125 minutes for the new battery.