User's Manual

AC65/AC75 Hardware Interface Description
Confidential / Preliminary
s
AC65/AC75_hd_v00.372 Page 43 of 118 2006-08-03
3.5 Charging Control
AC65/AC75 integrates a charging management for rechargeable Lithium Ion and Lithium
Polymer batteries. You can skip this chapter if charging is not your concern, or if you are not
using the implemented charging algorithm.
The following sections contain an overview of charging and battery specifications. Please
refer to [4] for greater detail, especially regarding requirements for batteries and chargers,
appropriate charging circuits, recommended batteries and an analysis of operational issues
typical of battery powered GSM/GPRS applications.
3.5.1 Hardware Requirements
AC65/AC75 has no on-board charging circuit. To benefit from the implemented charging
management you are required to install a charging circuit within your application according to
the Figure 46.
3.5.2 Software Requirements
Use the command AT^SBC, parameter <current>, to enter the current consumption of the
host application. This information enables the AC65/AC75 module to correctly determine the
end of charging and terminate charging automatically when the battery is fully charged. If the
<current> value is inaccurate and the application draws a current higher than the final charge
current, either charging will not be terminated or the battery fails to reach its maximum
voltage. Therefore, the termination condition is defined as: current consumption dependent
on the operating mode of the ME plus current consumption of the external application. If
used the current flowing over the VEXT pin of the application interface must be added, too.
The parameter <current> is volatile, meaning that the factory default (0mA) is restored each
time the module is powered down or reset. Therefore, for better control of charging, it is
recommended to enter the value every time the module is started.
See [1] for details on AT^SBC.