Why do laptops shut down when their battery is almost empty? I'm basing my facts on Windows machines, but they always seem incapable of going past 5% without shutting down.
(Because smartphones on the other hand, seem to be able to go the whole way to 0% before shutting down. Most of them seem to still have a small amount of "reserve" power at the declared "0%" value. I guess that it rounds down, so ~0.4% would be 0%. I'm pretty sure iOS does the same as well.)
So, Why do laptops (especially on Windows) shut down on 5% and don't run until they die by default? Is there a factual reason for this? For example, do laptops have a sufficiently complex shutdown process (in which the system can lack the ability to do so if the battery power is too low)?