$this->db_host = $datos_conexion['db_host'];
$this->db_user = $datos_conexion['db_user'];
$this->db_pass = $datos_conexion['db_pass'];
$this->db_name = $datos_conexion['db_name'];
$this->db_charset = $datos_conexion['db_charset'];

$this->connection = new mysqli($this->db_host, $this->db_user, $this->db_pass, $this->db_name);
if(!$this->connection){
  throw new ExceptionSicatsem("Error al intentar conectar con la base de datos");
}else {
    $this->connection->set_charset($this->db_charset);
}