Hondata

this might sound dumb but if i unplug my s300 in my ek and plug it into my ef will it keep the ek map without having to connect usb and laptop.
or if my battery goes dead will i need to reload my file to my s300.

basicaly im asking if i disconect the power supply to my s300 will i still need to conect a laptop once power is regained.

No the program is stored inside the s300 and is not lost if you unplug it.