2013 Nissan LEAF Battery Pack.

2013 Nissan LEAF Battery Pack.

Tons of mostly miniscule changes were made to the Nissan LEAF for 2013, most of which will go as unnoticeable to the casual observer, but some, including a somewhat disputed boost in range, are worthy of mention.

Officially, the 2013 Nissan LEAF is EPA-rated at 75 miles of range, but Nissan says that number is closer to 84 miles using the old EPA system.  Regardless of what Nissan says, the 2013 LEAF gets a 2-mile bump in range over the 2012 LEAF, according to the EPA.

So, the question is then, how did Nissan increase the LEAF's range when it's not at all obvious that changes deep within the LEAF were made?

Well, changes were made, but Nissan doesn't often discuss them, so we're all left scratching our heads while wondering how the LEAF's range improved.

Sure, there were some aero tweaks and a slight weight reduction (175 pounds), both of which contribute significantly to the bump in range, but there's more hidden inside.

Takeshi Miyamoto, engineering director at Nissan’s electric vehicle technology and development division, says upgrades to the LEAF have resulted in the increase in driving range—and notes that much of that bump in range comes from significantly reducing the weight of the LEAF's electric gear.

Nissan Worker Assembles 2013 LEAF Battery

Nissan Worker Assembles 2013 LEAF Battery

Miyamoto explains how the 2013 LEAF's electric powertrain joins the inverter, motor, power delivery module and reduction gear into a single unit, which reduces the size and weight by 30% and 10%, respectively.

But it's inside the the LEAF's lithium-ion battery where some of the truly hidden work took place.   As Miyamoto explains, the battery retains its basic structure (48 modules, each containing four 1.9V cells for a total of 192 cells), but modification to some components and a streamlining of the case's structure led to a weight reduction of 44 pounds.  Voltage and capacity (24 kWh) remain unchanged.

So, weight shedding may be the leading reason why the 2013 LEAF gets an increase in range, but now we know where and how the weight-loss work was done.