Mount-spcontentdatabase with SQL Authentication

Hi,

I'm able to Add database from Central Admin using SQL Authentication.

But when try Mount-Spcontentdatabase it's failing saying connot connecto dataabase.

Steps followed:

1. From management shell:

$secpasswd = ConvertTo-SecureString "Welcome123!" -AsPlainText -Force
$dbcreds = New-Object System.Management.Automation.PSCredential ("spadmin", $secpasswd)

2.

 Mount-spcontentdatabase "WSS_Content_DB" -databaseserver "Ins1" -DatabaseCredentials $dbcreds -webapplication http://servername:12582/ 

Error:

Mount-SPContentDatabase : Could not connect to spstage with user spadmin: Canno
t connect to database master at SQL server at Ins1. The database might not e
xist, or the current user does not have permission to connect to it.
At line:1 char:24

But the same is working from Central Admin. Please advise.

Thanks