The Chevy Spark EV is getting major surgery for 2015. The battery for the 2014 model was made by A123 Systems and could hold 20 kWh, but the new one will be assembled in-house by GM at its Brownstown, Michigan, facility using 192 lithium ion cells made by LG Chem. The new battery will only hold 19 kWh of power, but because it is also 86 pounds lighter, driving range and energy-efficiency should remain at the previous EPA numbers of 82 miles and 119 MPGe.
GM is probably doing this because its higher volume Volt and Volt-based Cadillac ELR are also using LG Chem batteries, so standardizing on one type of cell gives better economies of scale. It also seem, based on the weight, that the LG Chem battery has a better power-weight ratio than the A123 Systems one, so that's clearly better (it takes energy to lug around all this weight).
The 2015 Spark EV is currently on sale in California and Oregon and comes with gadgets like Siri Eyes Free, 4G LTE and DC Fast Charging (that's a good idea!). After federal incentives, it costs $19,995. A bit less if you can get state incentives too.