Copied from the Chucklehead Forum... The question of "What batteries do I get" and "Where do I order" comes up about a hundred times a week on the 'Saturday' thread. I just want to put as much batt info as I can here so that we can point ppl to this thread when the question comes up. Here is a rundown of batteries that can be used for the Chuck.... Large Chuck: 3.7V - 18650 6V - 2x RCR123 6V - 2x CR2 (need the sleeve sold at Thagbuilt.com, unprotected**) 6V - 2x CR123 (these are non re-chargeables that you can get in a pinch at most stores to use your large chuck at 6V) Little Chuck: 3.7V - 16340 (also sold as 3.6V CR123A, but make sure you get the 3.6V and not the 3V) 3.7V - 18350 (1200mAh, orange ones unprotected**, blue ones protected) ** Use unprotected batteries at your own risk. While it is unlikely that anything will go wrong, serious injury and fire can result from using unprotected batteries. ** Places to Buy: Look through the thread below for useful discount codes! MadVapes MadVapes LLC (US Supplier, good prices, carries protected 18350's) Battery Junction BatteryJunction.com Batteries, Battery Chargers, Flashlights, Solar Products & more! (US supplier usually 2-3 days to get) Lighthound Fenix Flashlights, Cree Q5 LED, Lithium Batteries, Lithium Ion Batteries, Li-Ion Chargers, Leatherman Multitools, Spyderco Knives and more! (US Supplier, good prices) Dealextreme DealExtreme: Cool Gadgets at the Right Price - Site-Wide Free Shipping (Page 1) (China supplier, best prices, but extremely long wait) Battery Tips: - Order your batteries and charger at the same time you order your Chuck, so you won't be stuck looking at an unusable piece of table art. ;-) - You can charge your batteries when they come. Don't wait for your Chuck to arrive. They will hold the charge and be ready for out of the box Chucking!