What to do if JBL Charge 3 or JBL Charge 4 not Charging?

Both JBL Charge 3 and JBL Charge 4 are waterproof, portable Bluetooth speakers. They prove the best companions for outdoor entertainment like the pool and beach. However, they have some differences and similarities. Before proceeding further, let us briefly compare and contrast the JBL Charge 3 and JBL Charge 4. Then we will proceed to know what to do if your JBL Charge 3 or JBL Charge 4 is not charging.