Rottenclam; you can indeed disconnect and take a battery amp like the RWA with you. The lit that tells you to leave it plugged in is should probably be clearer and let you know "you can unplug it if you like, but you don't have to and it is still running off the battery." Most leave it plugged in for simplicity sake (if the snarl of wires behind your rack is like mine, it's a pain to unplug something).
In the case of RWA, SLA batteries work best when fully charged at all times, so it makes sense it charges up every time after any use. Some batteries (like Lithion, I believe) will charge and power equipment better after being fully drained and can actually go bad if kept charged all the time.
In the case of RWA, SLA batteries work best when fully charged at all times, so it makes sense it charges up every time after any use. Some batteries (like Lithion, I believe) will charge and power equipment better after being fully drained and can actually go bad if kept charged all the time.