Onboard battery for embedded systems is an essential need for making them portable.
Maxim Integrated, A USA based IC manufacturing company released a reference design MAXREFDES96 which is based on their new Arduino Uno compatible shield. This shield is based on providing onboard battery charging and logging capabilities which can be utilised in smart portable electronics for data acquisition.
The board can be operated connecting it to a power supply or computer to charge a battery and operate untethered to use the battery to power the Arduino board. An SD card interface is provided to enable data logging up to 32GB of data. Status and battery state of charge (SOC) is displayed on three LEDs. It can be interfaced with a 16 x 2 LCD for the detailed status of the batteries.
Some of the features of the shield are –
- The shield is equipped with MAX1720x/MAX1721x. It is a low power stand-alone fuel gauge IC that implements the Maxim ModelGauge™ m5 algorithm without requiring host interaction for configuration. This helps in accurate monitoring of the battery regarding amperage use and battery life cycles.
- It has an inbuilt MAX77818 Battery-Management IC. It is the system which provides a balance charging system up to 13.4 Volts to lithium power batteries and claims to have an efficiency of 95.6%.
- The Battery Management Unit provides a battery charge rate up to 3.0 Ampere and a discharging rate of 4.5 amperes for fast charging management.
- It supports Smart Switching. It automatically switches between charge mode and boost mode to allow the board to switch from battery charging to boosted voltage which allows the board to run in stand-alone battery-powered applications.
The reference design contains all the information regarding Schematics, PCB design, Bill of Material(BOM) and design overview.
You need to have a user id in Maxim Integrated for downloading all the design files.
The features which are provided by the designed shield are suitable for applications focusing on standalone data Logging devices such as WIFI based Mesh devices, Sensors connected in a network using IoT etc. As this design included a battery fuel meter, it is useful to analyse and determine the power dissipated by the sensors and portable devices.