– 18650 size and dimension are fix. Li-Polymer size and dimension are flexible.

– 18650 produce more heat. Li-Polymer are much more safer.

– 18650 are cheaper. Li-Polymer are more expensive.

– 18650 have higher self discharge rate.Li-Polymer have a very low self discharge rate.

– 18650 battery durability will drop faster. Li-Polymer battery capacity are more durable.