Not sure which category the Nevada goes under …
I was advised to disconnect the battery while I was on holiday, so disconnected the negative. Returned after 4 weeks, reconnected the negative and not a thing - no lights, no nothing. The battery is fully charged. Any ideas? Thank you 
…
First off, I’d give both terminals and leads a clean. Happened to my car once. The RACV bod came out , twisted both connections on their posts and, voila, power restored!
You have the correct category
I’m cleaning the terminals now and checking the voltage in the battery - it does appear to be charged.
Got it going … it’s a great learning curve for me. It’s a lovely bike and it wasn’t the bike, it was me! I hadn’t realised there was an additional cable to be attached to the battery terminal. I’m still on the old bikes where there’s only one to each terminal! At least I got to clean all the connections. Away we go. Thanks everyone 
…
I did wonder if that was it - been done before! 