you have to make sure you have 1+ - 2+ - on both the battery connection and the the tap connection
You connected as 1+ - 2+ - on battery and 2+ - 1+ - this creates a short in the connections.
The safest way is NOT to bridge the - and + balance tap connection bits together - this way if you mis-connect you don't get fire...
Note red wire removed from second (-) side pack