First the external charger dies... so I have to open the case more than usual. Then the hinge breaks off.

Is that a mere accident?

NO.

What's also odd about this LED bike light is that the MSP430, which itself drives a FET for a buck driver, starts the whole thing in high-brightness-mode. After that you can switch it to low-brightness-mode. The logic behind this if seriously flawed. If the battery is nearly dead, it instantly turns off again, instead of directly going to 'emergency' low-power mode.

I wonder how much practical experience the designer had at the time.