They get weaker as they are recharged and discharged many times. Its like a shoe: after wearing it for some time, they wear away.
Laptop battery life depends on a variety of factors. Typcially Dell has higher rated batteries.
After charging laptop it will 3 to 4 hours backup
The lifespan of 3 AAA batteries in a flashlight depends on various factors such as the capacity of the batteries, the power consumption of the flashlight, and the usage pattern. On average, standard alkaline AAA batteries have a capacity of around 1000-1200 mAh each. If the flashlight consumes 100 mA of current, the batteries could last approximately 10-12 hours. However, if the flashlight has a higher power consumption, the batteries may last for a shorter period.
Last time this happen to me, it was a sign of the battery going bad. It kept stop charging at shorter and shorter period until my battery can barely hold 10 minutes worth of power.
A good place to find replacement batteries for Dell laptops is eBay. It is possible to find batteries for less than $10, but they might not last as long as Dell-manufactured batteries.
The average life for a laptop battery is between 3 to 4 hoursand sometimes even less than 3 hours.
By fully charging and fully discharging some batteries the expected charge time can be increased. Some rechargable batteries will last longer per charge if they are fully discharged before you recharge them again. Recharging batteries before they are fully discharged may cause a battery memory effect that will allow the battery to run for a shorter period between recharges.
Samsung laptop and hp laptop batteries are really good and last very long.As my laptop give minimum of 6 hours of internet browsing .
You could just have a shorter cycle. Some women have a long cycle(over 28days) and some have shorter ones.
You can find good batteries that last a while on Best Buy and Fry's sites. But you should know that it also depends on your laptop brand and model on how long your battery will last.
According to manufacturers, you should never remove the battery when the computer is plugged in. Removing the battery does not extend battery life because all batteries have "shelf" life and are no good after a certain time. Today's batteries actually will last longer if you keep it in the laptop.
There are several reasons why your laptop's battery doesn't last very long, sometimes batteries can develop a "memory" if they aren't recharged properly or your battery could simply be getting old. If your laptop is under warranty, then you may be able to get the battery replaced for free.