16x 4/5AA Battery 1.2V 1300mAh Flat Top Rechargeable NiMH Battery PKCELL US | eBay
Amazon.com: GLEPOWEER 4 Pack 4/5 AA (NOT AA Size) 14430 3.2v 500mAh LiFePO4 Lithium Rechargeable Solar Battery Pack Replacement for Outdoor Solar Lights : Health & Household