DBL™ DOUBLE BATTERY LIFE DBL™ DOUBLE BATTERY LIFE Optimize your battery cycles. DBL optimizes charging cycles and increases battery life up to 100%. Standard on IPC high frequency battery charger. Applied to: CT231 CT71 CT51 CT81 CT230 CT160 CT110 CT80 CT105 CT15 Benefits Extended battery life up to 100%. Optimize the charging cycles. Recharging optimizes only when required.