8 Smart Battery system and dual buck converter
Kontron User's Guide nanoETXexpress-HMI
Baseboard (ePDAnano)
30
8
8.1
8.2
Smart Battery system and dual buck converter
Introduction
The Core of the SBS is the dual Smart Battery System Manager LTC1760. On the ePDAnano baseboard
only one battery connection is provided.
Smart Battery Systems have the ability to communicate with the application. Therefore the user gets
information about the current state of the battery. The interface for this communication is the System
Management Bus (SMBus). Standard Smart Batteries have a specified 5 pin header, connecting to the
power lines and additionally this SMBus. This standardization allows using all available kinds of standard
Smart Batteries, which also applies to the ePDAnano baseboard.
A typical SBS consists of a Smart Battery System Manager and a charger, which can communicate with
the chipset using the SMBus. If there is no software to control the SBS via SM-bus then the system is
able to run in a stand alone mode with reduced functionality, too.
The SBS was designed for the requirements of the ePDAnano Baseboard. Therefore the input voltage can
be supplied with a DC wall adapter in a range of 9,6V to 14V. Additionally different kinds of Smart
Batteries can be used. That means different battery chemistry and cell configurations. But it must be
ensured to use standard Smart Batteries, which meet the SM-Bus standard.
Possible Smart Batteries
The SBS hardware is configured for a maximum charger output voltage of 8,4V and a maximum output
current of 2 A. Smart Batteries with a nominal voltage of 7,2V, e.g. NiMH and NiCd with 6SxP (= 6 cells in
series and x in parallel) or Li-Ion and LiPo with 2SxP (= 2 cells in series and x in parallel) are possible.
Battery Manufacturer:
http://www.moltechpower.co.uk/smart_standard_range.htm
e.g. ND2057, NH2057
http://www.inspired-energy.com/Standard_Products/standard_products.htm
http://www.emergingpower.com/oem/oem_standardpacks.htm
8.3
Smart Battery System Manager
The LTC1760 SBS Manager is a highly integrated level 3 battery charger and selector intended for
products using dual smart batteries. Three SMBus interfaces allow the LTC1760 to servo to the internal
voltage and currents measured by the batteries while allowing a SMBus Host to monitor either battery’s
status. Charging accuracy is determined by the battery’s internal voltage and current measurement,
typically better then ±0,2%.
