I have a Battery Tender Jr. for the battery in my SWing and 1974 Honda CB750. I also changed both batteries over to the Battery Tender Lithium Ion batteries. They are a lot lighter (1.75 Lbs) and a lot smaller. They come with dense foam pads of various thickness to fill up the empty space left over so the battery doesn't "flop" around in the compartment. Each pad has a self-stick tape on it to hold them in place on the battery. I can go out to the SWing and check the voltage and it's always been holding around 13.5 volts even after sitting for a week, which doesn't happen all that much in the summer. The CB750 doesn't have any drain on the battery like the SWing does so it holds at its max voltage with no problem. Over this coming winter I'll put the Battery Tender Jr. on the SWing about once a month to keep it ready for the two or three weeks of summer we have here in Minnesota.
So far I love the Lithium Ion batteries. They have plenty of power and work great. If memory serves they are 240 CCA batteries.
And a P.S. I talked to Battery Tender about using the Battery Tender Jr. on these batteries and they said it will work with no problems. They also have a Lithium Ion maintainer charger but seeing as my garage is attached to my home I can go out there once a month and put the Jr. on it every so often.