How many riders have had the oem battery fail within 18 months. Been noticing my battery going low this winter so i have been using a C-tek charger on it on a weekly basis to keep it up. Thought i may have a parasitic drain so i removed the battery and did some testing. Found after a full charging the battery had dropped to 12.2 volts after 24 hours off the charger with no loads connected. Decided to install a YZ450 lithium battery to see how that goes. Still need to add spacers to take up the extra space.