While we really need an Apollo Program for batteries, just a decent amount of research and development would be good.
If there is a technology realm that could have a larger impact on today's society and yet has been less funded and had slower growth, I haven't seen it.
Think about batteries, all the places you use them, and all the places they could be used. The critical limiting factor in my hybrid cars performance is the weight of that huge battery pack under the back seats. If the storage capacity went up, or the weight went down substantially it would make a huge difference in my mileage. It's also the limiting factor in electric cars. Similarly think about how much of your laptop's weight is in the battery, and of course the limited charge time, and the limited number of times you can recharge the battery, and the exploding, etc.
But the applications aren't just limited to current uses of batteries. The major hurdle to switching off of fossil fuels into renewable energy sources is energy storage. You can blanket the country with solar panels today, but it wouldn't help you one whit once the sun sets. The same applies to wind power, you need a way to store that energy for when the wind stops blowing.
Despite the obvious demand for better technology, and the many places where new technology could be adopted, there's really been little investment in improving the humble battery. Given all that, I'm excited to see some progress in the area of supercapacitors, as witnessed by this nanotube paper battery. Check out this article in IEEE Spectrum for more details on the developments around supercapacitors and their applications.