I've fitted one to my 3AJ. Its the small fitment being the same as a BMW. I brought it from my local bike store which also sell's these battery charging systems.

Anyway I've fitted it on the dash above the choke, first drilled a pilot hole then used a wood drill bit to get the required size, taking it very easy, cleaning up with a small file, don't get to carried away as the plastic is quite soft. The Earth wire went to the light earth fitting. The Positive lead I covered with a piece of old fuel hosing as its strapped to the chassis under the tank. I wanted to be sure I didn't rub it through. There is a few centimetre extra at the battery end in case its ever pulled, I've also fitted an inline fuse. Its been on the bike for over a year without any problems. It does have the waterproof cap, just as well really as its always bloody raining here....

The only down side I see is, leaving electrical goods attached with the engine off or trying to pull too much current. Personally I think a telephone battery charger or PDA is fine.

It took an hour or two to fit at a very steady place, only problem is now I've seen the underside of the tank and that's going to need some rust prevention work.

Now I need to find time to build a centre stand, luggage racks and enlarged the side stand foot.

cheers
Matt