Lithium Ion Cylindrical Battery - 3.7v 2200mAh : ID 1781 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits
3.7 Volt Li-Ion Rechargeable Battery MDHAND (4 Pack) HIGH Capacity 6000mAh,Digital Battery 1C- Flat top - Walmart.com
Amazon.com: PKCELL ICR17500 Battery 3.7V 1100mah A Size Lithium Rechargeable Batteries with Flat Top 2pcs(They are not 1865mm Size Battery) : Health & Household
Amazon.com: PKCELL ICR18500 Rechargeable Li-ion Battery 3.7V 1400mAh Battery Button Top 2pcs(Battery Size 18 * 50mm) : Health & Household