Battery: Chevrolet Bolt EV vs Chevrolet Spark EV (updated)
GM’s electric cars use LG Chem cells for their batteries. These cells are considered by GM’s competitor Renault-Nissan CEO, Carlos Ghosn as top notch. I understand why.
Let’s make a quick comparison between Chevrolet Bolt EV and Chevrolet Spark EV batteries.
The Chevrolet Bolt EV battery is made with 288 (96s3p) LG Chem cells (LGX N2.1), each cell is rated at 60 Ah and 3,6 V. This represents a total of 62,2 kWh (288 x 60 Ah x 3,6 V). The battery volume is 285 L and the mass is 435 kg, this means an energy density of 218 Wh/L and 143 Wh/kg at the battery pack level.
While the Chevrolet Spark EV battery is made with 192 (96s2p) LG Chem cells, each cell is rated at 27 Ah and 3,65 V. This represents a total of 19 kWh (192 x 27 Ah x 3,65 V). The battery volume is 139 L and the mass is 215 kg, this means an energy density of 136 Wh/L and 88 Wh/kg at the battery pack level.
Both batteries have liquid active thermal control that is very important to keep the battery at ideal temperature, since high temperatures damage the cells.
We know that the Spark EV’s small 19 kWh battery can handle high charge and discharge rates, since it can be discharged at 120 kW, of which 105 kW are intended to the motor, and can take up to 50 kW in CCS DC fast chargers. While Bolt’s 62,2 kWh battery can provide at least 150 kW to the electric motor and something more to the electronics.
What is still unknown is how fast the Bolt’s battery can be charged at a CCS fast charger. GM has been saying that this electric car with more than 200 miles EPA range will charge at 90 miles per 30 minutes. This means that a complete charge would take more than an hour in a CCS fast charger. But we have to take in mind that GM has to say this because virtually every CCS charger in the USA is limited to 50 kW and GM doesn’t want a class action lawsuit.
Since in Europe we already have a few 150 kW CCS fast chargers, Opel might reveal how fast the Ampera-e can actually charge. Anything less than 100 kW is a major letdown, 120 kW would be great.
Update: LG Chem rates Chevrolet Bolt EV’s usable battery capacity at 57 kWh.