Sony SGPT11 - Manual (Page 10)

Notes on Using the Battery
About the battery
For your safety, use only the supplied AC power cord (mains lead) for battery charging.
Depending on the ambient temperature or how to use your tablet device, the battery may not be charged, or it may take a long
time to charge the battery.
Do not charge the battery near fire or in direct sunlight.
The tablet device is not fully charged when shipped.
Heat builds up in the battery while it is in use or being charged. This is normal and is not cause of concern. If your tablet device or
the AC adaptor becomes abnormally hot, shut down your tablet device and unplug the AC power cord (mains lead) from the AC
adapter.
About battery discharge
After charging, the battery gradually loses its charge even if it is not used. If it is left unused for a long time, the battery charge
may be depleted. We recommend recharging the battery before use.
If you do not use your tablet device for an extended period of time, fully charge the battery every six months.
About battery life
Battery life varies depending on usage, settings, and temperatures.
About battery deterioration
Battery capacity gradually declines through repeated recharging and discharging. As a result, the battery life may become short
or the battery may not perform optimally even when fully charged.