Alien Motion AM4-XP Lightweight Lithium Battery (LiFePO4) – Yamaha R3

• Ultra-Lightweight and High Power Lithium Motorsport Battery
• Holds a charge with minimal drain for years when there is no draw on power
• 2-Year Warranty and Out of This World Support from Alien Motion
• Great for everyday use for bikes and scooters 50cc to 550cc (Alien Motion Recommends the AM8-XP for 450cc singles)
• Works with the original charging system
• Great for racing applications
• Significant cost savings and longevity compared to lead acid

From the Wikipedia page on LiFePO4 batteries:

“The lithium iron phosphate (LiFePO4) battery, also called LFP battery (with “LFP” standing for “lithium ferrophosphate”), is a type of rechargeable battery, specifically a lithium-ion battery, which uses LiFePO4 as acathode material. LiFePO4 batteries have somewhat lower energy density than the more common LiCoO2 design found in consumer electronics, but offer longer lifetimes, better power density (the rate that energy can be drawn from them) and are inherently safer. LiFePO4 is finding a number of roles in vehicle use and backup power.”