This LG INR18650 M26 2600mAh Lithium-Ion Battery gives value for your money. It comes with a rated voltage of 3.7 volts and a capacity of 2600mAh. It is a single cell, compact, and powerful battery cell with 2600 mAh capacity. It is very convenient to install in your project to fulfill the 3.7 Volt requirement with high capacity.
The battery terminals can use in any compatible battery adapter/holder or it can be permanently soldered to your applications power source wires.