Because all Okluma flashlights use rechargeable Li-ion IMR batteries, you will definitely want to pick up a battery charger if you don't have one. The Nitecore D2 works just as well at it's bigger brother the Nitecore D4, but takes up less real estate on your counter. If you don't have a charger yet, this is what we recommend. It charges batteries quickly and safely. For more details, check out the Nitecore D2 page here.