I will try to list all the modification’s I have done on this Buell:

First off all the battery, I had some crancking problems when the engine was cold. Figuring this out I learned that the battery installed ( Dynavolt) had only 180 CCA (Cold Cranking Amps)
The original battery OEM 65989-97C has 280 CCA but is very expensive.
On my search I discovered a Lithium battery with 330 CCA.
It was the same price as the OEM battery and almost looks the same.

I really like the weight saving.
The OEM and aftermarket battery weigh 4.5 Kg, the Lithium Battery weighs only 1.2 Kg. 
That’s an amazing 3.3 Kg.