The invention provides a battery 
state prediction method and 
system. The method comprises steps of: establishing a random 
data assimilation function model I*t = f(U, I, T) representing a function relationship between the dischargeable time t of a battery and 
voltage U, current I, and temperature T; computing the complete 
discharge curve Ik*t = f(U, Ik, Tk) and the dischargeable time tk:tk= f(Uk, Ik, Tk) / Ik of the battery to be tested on a current operating condition by using the random 
data assimilation function model I*t = f(U, I, T) and according to the 
voltage Uk, the current Ik, and the temperature Tk, measured in real time, of the battery to be tested; and predicting the SoC value and the SoH value of the battery to be tested according to the complete 
discharge curve and the dischargeable time of the battery to be tested on the current operating condition. The battery 
state prediction method and 
system may perform assimilation treatment on battery parameters on different operating conditions, adapt to operating conditions with continuously changed 
discharge current and ambient temperature, may accurately predict the 
state of health and the 
state of charge of the battery, and is good in instantaneity, high in accuracy, and easy to implement.