|If you are taking the battery out to get a new one, you should be OK. Unplug the charger and let the laptop set, or take it with you. The battery is to operate the unit without the charger. Leaving the battery out for days is not going to cause problems. Refer to the owners manual to verify that the unit has to have the battery in place to use it with the charger.|
There is a small battery internally, but that is for hardware settings, not program data. Program data is stored on the C: drive, usually. It doesn't require power to hold data.