There is a great importance of batteries in the functioning of many devices. Vehicles occupy a major spot among them. This thesis emphasizes of a smart electronic device for 12V lead-acid batteries. The deduced name of device is BAT-UP! It is able to sample the battery sample and provide it to the final user. Apart from this, the device is capable of providing State Of Health and some parameters such as State of Charge and Time To Criticality. The State Of Health shows the ageing of battery and it is produced using the open circuit voltage function. The second is a prediction of time that when the battery may start to work under critical voltage threshold, and is obtained through reconstruction of voltage profile with RLS estimator.