Envisys Your One-Stop Shop for Lithium-Ion Battery Testing Chambers. Envisys, Is a top producer and distributor of high-performance, high reliability Battery testing chamber products. Specifically designed for lithium-ion batteries. From primitive testing to advanced certification, our chambers are designed to meet all your needs. Battery manufacturing is a process that involves R&D and quality assurance. . Our temperature testing services are not limited, as we also offer a range of lithium-ion battery testing equipment.