Did you get a genuine key? I never had one fail on me.
The immobilizer is the single best piece of technology for preventing car theft. If you create a backdoor for bypassing it, you'll end up like Hyundai/Kia which decided to sell cars without the immobilizer in recent years and which have turned into a joke in the minds of potential customers.
It does not require a battery in most cases and is separate from the keeloq system that controls your car's doors.
The immobilizer is the single best piece of technology for preventing car theft. If you create a backdoor for bypassing it, you'll end up like Hyundai/Kia which decided to sell cars without the immobilizer in recent years and which have turned into a joke in the minds of potential customers.
It does not require a battery in most cases and is separate from the keeloq system that controls your car's doors.