I have a Grizzly 450. Recently I have got through 3 new batteries, each lasting around 2 to 3 months. When they are new they charge fine and continue to do so for a while. Then something happens and I start getting a rapid clicking when first starting in the morning especially when its cold. It starts but only with rapidly pushing the start button. Eventually after a few more weeks the battery dies. 2 experienced mechanics have checked it out but have not managed to diagnose the problem. One suggestion is that there is an AC current getting into the DC battery, eventually buckling the cells. Once the cells touch each other the battery is no good any more. We've had the quad since new in 2013 and it was fine for the first 5 years. We've had a new starter motor and the rear light was fixed by our mechanic during a routine service. The rear light he fitted was a "Landrover" light. It's a great quad. Has taken a bit of a pounding but still holds it own. I am reluctant to get rid of it and would love to hear any suggestions as to what we are not seeing.