This work has a 7 - day warranty if it is not as you would like — see terms for details of such warranty: terms of service. (abstractartist.info)
In general, I think it's ethically fine to offer such warranties, even though they're generally a bad deal. (canadianbusiness.com)
The battery in the Sonata Hybrid is a lithium - polymer design that is lightweight and energy dense, yet it is engineered to discharge much slower and retain more energy, and Hyundai backs the battery with a limited lifetime warranty, the first such warranty offered on a hybrid. (autobytel.com)