[yosyp]

You wouldn't want to combine a solar cell and a battery in a single package; maybe in a modular system instead. After some amount of charge/discharge cycles the battery will quickly lose its capacity and utility. I suspect the operational lifespan of photovoltaics is much greater than the best batteries, and will continue to be for some time in the future.

[wernercd]

Well, when I say "single package" I mean provided by a single company. As in a complete package: Solar panels, batteries, etc. The full deal.

I would expect the battery to be in the basement/garage/etc and not on the roof with the panels.