I am weary of it solely because it seems too good to be true but on the other hand can we hurry up with smart phones that never need to be charged?
Also though I have to wonder, could these be used in things that aren't using power all the time? Like, lots of devices use power intermittently. What happens to the excess energy when the battery isn't in use? Just dissipates? Or would you simply not use these batteries for such an application?
Well with an average consumption of maybe half a Watt over the course of a day, you would need 5000 of these to power your phone given they put out 100 microWatts.
They did, but from the sounds of it I'm guessing they're just gonna be a physically bigger one. This is a very very small battery, but produces very little energy. But easy enough to just slap a few of them together.
Unfortunately, it doesn't change the power density or anything like that.
This specific technology will never be in charge of running a smartphone or anything like that. But maybe a tweak or innovation on these radioactive batteries could get them to be a few watts and you could get a super low-powered cell phone device that could be used in emergencies only and last for like 50 years.
You're conflating Watt-hours and Watts. Watts are a measure of power, which is energy consumption per unit time. Watt-hour is power multiplied by time, the time cancels and so it's a measure of energy. 0.5 Watts for an entire day adds up to 12 Watt-hours in a day, which is a reasonable estimate for a phone battery.
My guess is that excess power is just going to keep on building up until the voltage gets high enough that its self-discharge surpasses its generation capacity and effectively turns any excess energy generated directly into heat.