Niterider will repair it out of warranty for $25 plus the cost of shipping it to them https://www.niterider.com/niterider-warranty/ Only you can decide if spending this much to resurrect a $65 light is wise. If they simply give you a brand new light it might be a bargain but if they return the light with the old battery inside it may not be so good a deal. Li-ion batteries have about a 500 recharge cycle according to most battery sites.