12V 40Ah Custom Lithium Battery Pack is Rechargeable and safe
Lithium Battery Technologies - Li-Ion and LiFePO4 Battery Pack Systems
Amazon.com: Rechargeable Lithium Ion Battery Pack - VIDAR 3.7V 5200mAh High Capacity Li-ion Battery Pack with JST PH2.54/2P Plug-in(Customizable) for Electronics,Toys,Lighting,Equipment : Health & Household