Time dependent material properties

Hello

I'm trying to make a simplified thermal model of a Li-Ion battery. I'm using the Joule Heating model and a time dependent study.

I want to model the State of Charge with either an integration of the current going in / out of the battery over time - or simply a piecewise function of time (since the current is constant +/- X Ampere).

I've made the piecewise function, but when I try to make the electrical conductivity a function of time it stays constant during my simulation.

Is there anyway to make a material property a function of simulation time?

Greetings
Kasper Jørgensen