I've been hearing good things about these new Lithium Iron Phosphate batteries for motorcycles so I took the plunge and purchased a 12-cell battery from SYCL: www.testsycl.com. Other than shedding the advertised 6-7 pounds, the battery takes up far less space. It fits well into the HP2's battery port but takes some tweaking to get it to sit without risk of shaking loose. At some point I should amalgamate the electrics and simplify the routing of wires on my bike! But for now I'll stick with this. I think I'll use the storage space to store some tools. So far so good. I'll take it for a test ride today, and an extended ride tomorrow.