But in may cases the device becomes "obsolete" because its battery no holds adequate charge and is intentionally not replaceable. For example, that's certainly

But in may cases the device becomes "obsolete" because its battery no holds adequate charge and is intentionally not replaceable. For example, that's certainly the case with Microsoft Surface Pro [1,2,3,etc.] computers as MS made it clear that the design life of the battery was about 3 years (and isn't user replaceable). That's absurd for a device with an initial cost of >$1500. If the battery lasted 20 times as long, I'm sure many such devices would be kept in service for much longer than 3 years, for many users there's no need to "upgrade" after so short an interval.