Can the EcoSharp 40 V 4.0 Ah battery pack (model iBAT40) and the EcoSharp PRO 40 V 5.0 Ah battery pack (model iBAT40XR) be used interchangeably with all iON tools?

Yes, both the EcoSharp 40 V 4.0 Ah battery pack (model iBAT40) and the EcoSharp PRO 40 V 5.0 Ah battery pack (model iBAT40XR) can be used with all iON and iON PRO series tools. Both batteries also utilize the same 40 V EcoSharp charger (model iCHRG40).