Optimate do a number of handy accessories that plug straight in to your battery minder plug if you have one.
I recently picked up the Power Socket for $11. I will eventually take the tank off & reroute the wires to get it into the dashboard area, as I needed an excuse to take the tank off again to wire the Main & Dip beam to come on together as I forgot the first time round.
The only thing is the socket will be live all the time, not switched.
I was also interested in the volt LED display that can fit between the two connections of the battery lead and socket connection but isn't available here yet.
Just thought this is an easier option for people like me that aren't overly confident in electrics.

Get yourself one of these. Been worth it's weight in gold. Small (so can be fitted easily) and can be set to act as a charge or battery voltage monitor. Get one delivered to your folks place in the UK to keep the postage costs free.

See here from post #7 for piccies of it fitted the Z.

__________________

Thanks for that Pleiades, I'll get onto it in the morning as looks as though he doesn't have many left.