In the user manual for the 05SD it says to disconnect the negative terminals from the battery before charging so as not to damage the bikes electronics.

I want to install a permanent CTEK charging connection to the battery so I can top up the charge when the bike sits for a couple days in the cold but that would mean leaving the negative harness connected (for obvious reasons)

Anyone have any experience with this? the CTEK 0.8 is a 5 stage charger so and is more of a trickle than anything. my assumption is that the CTEK charger would be ok but a quick unregulated charger could damage the electronics. Thoughts?

I have a permanently wired Oxford optimate battery tender on my 05SD which I have use on occasion and the previous owner used every winter from new (he was a summer only rider). Never had any problems.

For a battery tender I wouldn't worry - the most my optimate will put in is 0.8 amps @12v. For a 'normal' charger, I would disconnect the battery.

I guess their worry is if your charger I's faulty it could in theory throw a high voltage through the electronics and fry lots of stuff (like a faulty reg/rec would do)

Heaps of people use or used (me included) trickle chargers on the 990 as the battery needs to be tiptop to start.
Never had any issues or heard of any due to the use of a trickle charger.
That's why they come in the box with a lead to wire them in permanently.

Thanks for your feedback guys, appreciate you confirming what I already thought.

The only reason I bought it up is because I went against my instincts and actually read a user manual

Will proceed with the install.

On the up side next time someone like me uses the search function this topic should help them out!