The task behind this thesis was to develop both circuit and software for controlling lithium batteries. The electronic part consists of an integrated charger, battery parameter gauge and micro controller. After the electrical scheme has been developed by the use of computer program, printed circuit board was also developed, and finally the elements were soldered. The electronic part has input connectors for connecting multiple power sources as well as a USB port. With additional connectors attached to all pins of the micro controller, the system can be used as a development board. The software part is developed in language C. The system communicates using an I2C bus on which integrated circuits exchange data. Dedicated C library was developed for working with integrated charger BQ24195. It can be used to configure charger parameters such as charging current, input current, battery voltage, short circuit protection, high voltage protection, safety timers and many others. All essential parameters are displayed on the display. Finally, a comparison was made between the project developed system and the existing systems on the market.