Customer is responsible for shipping their core (defective battery or inverter) to Hybrid Drive Batteries located in 22607 La Palma Ave Suite 406 Yorba Linda Ca 92887. All defective batteries must reach Hybrid Drive Batteries located in Yorba Linda Ca within 30 days upon delivery date in order to be eligible for a core deposit refund. Customer is responsible for reading the instructions that are sent with the battery they purchased in order for them to ship their defective battery properly, improper shipping that leads to damage of the defective battery will be deducted from the core deposit.