"Solar"-powered devices
 

I have a coupe of so-called solar powered calculators that I keep on my desk. During the summer, enough light gets in so that I don't worry about not having enough juice.

Winter-time, it seems the ambient light from my incandescent bulbs was keeping them charged OK, too. In the last week, though, I switched out the regular bulbs for LEDs. The light looks white (the box lists their temperature as 2700K), but it doesn't seem like they are charging properly. I imagine one would have the same problem with other solar-powered devices

Are the solar panels in these calculators (and presumably other devices, too) actually as sensitive to non-solar light as to regular sunlight? I assume there is some optimum range, but I don't know what it is.