Hi I was given an '10 Inertia and enjoyed it for a year, but due to some unexpected geographic moves, the bike has sat uncharged for nearly 3 years. the battery is showing no signs of life, upon giving a charge a try (for about 30mins, seeing if any sign of being able to take a charge). I'm wondering if there is a relatively affordable route toward replacing/repairing the battery, or is an entire new battery system needed, which i'm assuming is north of 2-3k? Any thoughts on steps?