  The $g$-extra edge-connectivity is an important measure for the reliability
of interconnection networks. Recently, Yang et al. [Appl. Math. Comput. 320
(2018) 464--473] determined the $3$-extra edge-connectivity of balanced
hypercubes $BH_n$ and conjectured that the $g$-extra edge-connectivity of
$BH_n$ is $\lambda_g(BH_n)=2(g+1)n-4g+4$ for $2\leq g\leq 2n-1$. In this paper,
we confirm their conjecture for $n\geq 6-\dfrac{12}{g+1}$ and $2\leq g\leq 8$,
and disprove their conjecture for $n\geq \dfrac{3e_g(BH_n)}{g+1}$ and $9\leq
g\leq 2n-1$, where $e_g(BH_n)=\max\{|E(BH_n[U])|\mid U\subseteq V(BH_n),
|U|=g+1\}$.
