I'm kind of surprised that I haven't seen more discussion on Li-ion batteries. Joe Turner at http://www.turntechbattery.com produces and sells a line of motorcycle compatible Li batteries in various sizes. Advantages of Li batteries over standard lead/acid batteries include: much lighter weight; hold charge longer; very durable & long-lasting, plus they are fully compatible with the bike's charging system.
I have been using one of Joe T's 5Ah Li batteries in my '08 KTM (HTR 350) 250 XCF-W for 1,300 miles (57 hrs). Other than the initial charge, the battery has never seen nor required a Battery Tender and has never failed to E-start the engine even after the OEM fan has been running. Other than the fact that I like to experiment, plus of course the noted advantages, the main reason I went with the Li battery is that the stock 4Ah battery occasionally failed to E-start the high compression HTR 350 engine at inopportune times. Also, at 130$, the 1.6lb 5Ah Li battery was not all that much more expensive than the only other suitable replacement, i.e. the much heavier YTZ7S.
I have been using one of Joe T's 5Ah Li batteries in my '08 KTM (HTR 350) 250 XCF-W for 1,300 miles (57 hrs). Other than the initial charge, the battery has never seen nor required a Battery Tender and has never failed to E-start the engine even after the OEM fan has been running. Other than the fact that I like to experiment, plus of course the noted advantages, the main reason I went with the Li battery is that the stock 4Ah battery occasionally failed to E-start the high compression HTR 350 engine at inopportune times. Also, at 130$, the 1.6lb 5Ah Li battery was not all that much more expensive than the only other suitable replacement, i.e. the much heavier YTZ7S.
