"só pra ter certeza,fui pesquisar e foi na season4 mesmo
A reference to the company is also contained within the Lab Notes found by police in Gale's apartment.

Gale's Lab Notes with the reference to Madrigal Electromotive.

Brochure for Madrigal's HEPA
air filtration system
After assisting in the investigation into Gale's murder,
Hank explains the company's status to his former DEA colleagues. He also describes that when he began making inquiries into the purchase of the
air-filter delivered to Gale he discovered there was no record of who actually purchased it and, eventually, he was stone-walled by a corporate attorney ("
Problem Dog").
Hank discovers the industrial laundry that hides the superlab is owned by Madrigal Electromotive as well, and notes that such a location would be a good place to hide a meth lab ("
Crawl Space"). He has earlier appraised the high grade filter as perfect for a meth lab, but he has not yet able to connect Gus to the laundry operation. Hank is looking hard for that Madrigal hepa filter.
"