Amazon.com: Authentic 25RS, 3.7V Flat Top Real 2500mAh, 3.7V 18650 Rechargeable Battery(2 Pack) : Health & Household
Lithium Ion Polymer Battery - 3.7v 2500mAh : ID 328 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits
25R BATTERY INR18650 - 2500MAH 20A ( 2CT )
Amazon.com: SPARKOLE 7.4V 2500mAh Li-ion Rechargeable Battery for Speaker/Remote Control Toy/Bluetooth Boom Box/Portable DVD Player/Outdoor Lighting : Toys & Games