Let's do the math!
Gasoline is 32 MJ / litre, so 60 litres is 1920 MJ, or 533 kWh. However, there's only 25% efficiency in most engines, so this translates to useful 133 kWh.
Electric motors are nearly 100% efficient. Lithium ion batteries are 0.1 - 0.265 kWh / kg, so this is 502 kg - 1330 kg of batteries, depending on the exact battery chemistry.
I don't know which battery chemistry you used in calculations, but Tesla uses this: http://blog.evandmore.com/lets-talk-about-the-panasonic-ncr18650b/ which has 12 watt-hours of energy, and weight is 48.5 grams, so it's 0.247 kWh / kg, giving 538 kg of batteries needed. Tesla batteries are widely considered the best.
Note that of the 538 kg, you save at least 38 kg or even more, due to not needing a heavy gasoline engine and needing just a lightweight electric motor. Therefore, I would say the equivalence is about 60 liters of gasoline = 500 kg of batteries.
Note also, that electric cars can do regenerative braking. Thus, it might be even the case that 60 liters of gasoline in a regular non-hybrid car is equivalent to even as little as 400 kg of batteries. Of course, this depends on the driving (city vs highway) and the quality of the regenerative braking systems.
Edit: I didn't account for the structural parts holding the battery together in a nearly but not quite fatal accident. They need to be substantial. Thus, battery module weight is more than the sum of the weights of its cells.