NCE SB5 power supply 12v vs 13.5v

[Kiran]

On the NCE SB5 smart booster's power supply, there is a slider for 12v or 13.5v I have it on 12v at the moment for my N scale layout. Can someone explain what the difference between the 2 is? I remember reading that most Japanese models max out at 12v. Or am I mistaken?

 

Thanks.

[chadbag]

DCC usually runs an input about 1.5V-2V higher than what you would see on the track, if I understand it correctly.  Someone like @kvp or others more adept at voltages and how it all works could fill us in on the details.  12V setting should be OK though your max available voltage is less than 12V.  Safety factor.