Crust on Battery terminal

[Tex]

I installed new parallel batteries 12 months ago and recently a white crust has developed on the negative terminal on one of the two.
After cleaning the terminal the crust has started to show again.
Can any one advise the cause and a solution?

 

[NickRobinson]

Sounds like a failed seal where the terminal exits the case. Vaseline should solve the white cheese.

 

[VicS]

I agree its leaking....... take it back !