3 points
An article on APNews said there were multiple backups onboard… Which sort of engenders the thought of why they needed multiple backups. I’d be sure to have A backup, sure, but multiple?
1 point
My thought is are they from different lots and are the batteries from different manufacturers and different lots? You don’t want to have 5 devices and them all from the same batch and all fail in the same way. A company not concerned by safety probably wouldn’t consider any of this. I also bet their SOP didn’t include changing batteries every time, so you have to rule out that these spares probably weren’t getting charged up or have their batteries replaced either.
