RX400H 44k miles hybrid battery question
 

I was just given an RX400H not running. With codes P0AA1, O0AA4, P3030, P3105. This interior was very wet and hybrid battery relay box was almost solid ice and corroded. The batteries were tested for voltage and there was only 2.5 volts in the 2 large battery packs and under a volt in the middle battery pack. My question is since the car only has 44k is it possible to replace just the relay box and the batteries will be ok? All the other electronics in the car function but of course the engine does not run or crank.