0-60 MPH in 2.9s is not the same as 0-100 km/hr (62.1 MPH) in 3.1s.
At 2.9s 0-60, you're accelerating by 1 MPH every 0.04833 seconds.
At 3.1s 0-62.1, you're accelerating by 1 MPH every 0.04992 seconds, roughly 3.28% slower, which seems to match up with the LG vs Panasonic battery differences.
Extrapolate that through the entire quarter mile: If the Panasonic-equipped car traps 125* MPH, the LG-equipped car would trap 120.9 MPH. (125 x 0.9672 = 120.9)
* I have no proof of a 125 MPH trap speed, just used that number as an example. And I know the acceleration isn't linear, but the numbers do illustrate what a 3.28% difference can make when all other things are equal.