It works well even on rainy days, bus I had to buy a new one after 1 month of usage. The new one is still working so far, but I have only used it for 1 month.
From Voltaic: Hi Felix, Thank you for reaching out. Can you please email us with how you were using this extension cable? We have not seen this issue before and we'd like to be able to address in the future. Please email technical support at email@example.com