Solar flares should destroy random powered objects

[Ambaire]

If a solar flare is intense enough to shut down all power, then it's also intense enough to cause circuit overloading in the form of random voltage spikes.

I suggest that a solar flare also be an enhanced Zzzzt event. When it hits, your batteries will discharge and a number of devices will overload, explode or become damaged and require repair. If you have long, straight power conduit runs, they would resonate with the field impulse and cause additional damage.