Predictive Power Estimation of Dual Battery Systems in Mild-Hybrid Vehicles

Continuously increasing requirements for the vehicles' on- board system in terms of autonomous driving functions lead to new power network topologies. One promising concept is the usage of a 12 V dual battery system consisting of a lead-acid- and a lithium-ion-battery instead of a single lead-acid battery. The maximum system peak power depends on the current distribution between the two batteries, which cannot be controlled. This paper presents a new estimation method to predict the current distribution and thus the maximum system power. Estimation methods for standalone battery systems are compared to the new dual battery estimation method and vehicle measurements.