Aye. If I could do nothing else and had to do it, perhaps I would. If I don't, then I'll just use the proper one. ;-)
Other end of the sofa normally :$
At least you have the good nature to be embarrassed about that! :)
I've found a number of Canon compact cameras that run on 3.7/4.2V lithium batteries run fine on 5V. They may get slightly hotter but I hadn't noticed and I used this voltage to power my road trip time lapse camera the other year without any issues.
That makes sense.
Lithium batteries (as found in phones, cameras etc) generally output between 3.7 and 4.3 volts, depending on the current charge level. As you use the battery the voltage goes down. And yet you charge the vast majority of devices via 5v USB.
I suspect that the direct voltage from most of the batteries is fairly useless (because it's vsriable) and so anything using lithium would need onload voltage regulation to get something a bit more constant.