Should I keep my laptop battery charged all the time or run it flat?

Modern Laptop computers, netbooks, tablets, slates and phones all use Lithium Ion (LIon) or Nickel Metal Hydride (NimH) batteries. All these can be stored charged or discharged. However keeping them contiunuously charged up (the charger always plugged in) can cause problems, It depends on the battery management system used in the device.

I would recommend charging the device and then removing the charger. Use the device until the battery runs flat then repeat the cycle.

If you have to leave the charger plugged in all the time, then check the battery temperature from time to time. If it starts to get hot then it's not charging correctly or is overcharging. This can damage the battery's ability to hold a charge and may require replacement soon.