Since finding a branded 18650 Li-Ion battery is nearly impossible and the market is full of suppliers who are offering the clone lithium-ion batteries under the names of famous brands.
Those batteries are rated the same as standard lithium-ion batteries yet no one guaranty about their lifespan and also their performance is not as good as you expect.
This 18650 2600 mAh Lithium-Ion Battery gives value for your money.
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 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.