CHARGE IT! I've had 4GT's and my 18 350. The first 3 GT's all had full battery failure at around 2 years. I replaced with biggest mother bear that would fit. My last GT, and the 350 were put on a full battery charger the first night they were home. I was surprised how much charge was flowing into the new battery. I let it cook overnight and the last GT went away with the original battery, my 350 is at 3 years and doing fine on original battery. If your battery croaks, even under warranty, go out of pocket for Consumer Reports best battery. Insignificant cost versus reliability or getting stranded in your $60K beauty.