The cost of the battery is only ~10-20% higher than the bill of materials â suggesting a potential long-term competitive price for Lithium Ion batteries could approach ~$100 per kWh. Tesla currently pays Panasonic $180/kW for their batteries, although conventional systems still selling for $500-700/kWh.he cost of the battery is only ~10-20% higher than the bill of materials â suggesting a potential long-term competitive price for lithium-ion batteries could approach ~$100 per kWh.
n, pl -nies. 1. a declaration of truth or fact. 2. (Law) law evidence given by a witness, esp orally in court under oath or affirmation. 3. evidence testifying to something: her success was a testimony to her good luck.
Word Origin and History for testify Expand. v. late 14c., to serve as evidence of, from Latin testificari bear witness, from testis witness (see testament) + root of facere to make (see factitious). Biblical sense of openly profess one's faith and devotion is attested from 1520s.