Does anyone know what is the purpose of the second battery on a JDM market Land Cruiser Prado 90?

[PradoOverland]

So my land cruiser is a Japanese import and has the two batteries. Does anyone know what is the purpose of the second batteries (non starting one)? Can I actually run accessories of that without draining the starting batterie?

I think that is the logic behind it but I am not entirely sure

 

[TRDTom]

When you switch the car oof everything electrical you run off the car will draw power from the second non starting battery. SO yes you can run accessories of that which is pretty cool

 

[Frontier4x4]

Yep, it is for accessories when the vehicle is turned off. A very cool thing to have from factory!