Tesla Model S Battery Pack
The DOE Office of Energy Efficiency & Renewable Energy has released a comparison study between conventional hybrids (HEV) and plug-in electric cars (PEV), noting their total battery capacity vs number of packs registered.
Despite the fact that HEV sales are many times higher, their small 1-2 kWh batteries are nothing in comparison the to larger battery packs found in plug-in hybrids (PHEVs) or all-electric vehicles (BEVs) - which can be up to 90 kWh these days in the US.
Another takeaway from the study is that the battery pack themselves are growing; and even the momentary 2015 sales pause/decrease (waiting on new models and upgraded editions of popular plug-ins) didn't prevent an increase of total capacity - up to about 3.8 GWh (compared to just 0.4 GWh in 2011).
"The number of battery packs sold for plug-in electric vehicles (PEV) declined by 3.4% from 2014 to 2015. However, the total battery capacity for all PEVs sold between 2014 and 2015 increased by 22.6%. The rising battery capacities of PEV models have increased battery production even when sales of battery packs are down. Following the introduction of mass market PEVs in 2011, the total battery capacity sold increased nearly tenfold from 0.4 to 3.8 million kW-hrs by 2015.
The sales volume of hybrid electric vehicles (HEV), and therefore HEV battery packs, is much higher than for PEVs but their battery capacities are much smaller. Battery capacities for 2011-2015 HEV models usually ranged from about 1 to 2 kW-hrs while PEV models for this same period had battery capacities as large as 90 kW-hrs for a single battery pack. As a result, the total battery capacity sold for PEVs is much higher than it is for HEVs despite lower PEV sales volumes."
Number of Vehicle Battery Packs and Capacity Sold, 2011-2015 (source: energy.gov)