It's hard to beat the Deltran Tenders. They seem to work very well and forever! I've had mine for many years and use it on several bikes with no issues.
As a side benefit, you now will have a directly wired connection to the battery for accessories like an air pump or heated clothing. Just make sure to add a fuse to the circuit. On my GS I added an outlet on the beak that goes directly to the battery with a 15 amp fuse. I use the DIN plug adapter on the charger. I don't remember if it came with the DIN plug or if I built it
but since I have DIN plugs on all my bikes for the compressor and GPS it work on all of them.