I agree with mrgold. The whale bracket looks quite different from a dolphin bracket.
Range on an e-bike is proportional to the AH rating of the battery. The Luna whale is 17.5AH, which is 52% more than the standard 11.5AH radrover. So figure 50% more range. If you got 30 miles before, now you got 45, etc. If you're a battery miser and got 40, that bigger battery promises 60.
Looking at the 13.5AH vs 11.5AH Dolphins, there's a 17% increase. Same math.
Actual mileage of course depends on average speed, wind, rider weight, and how much you pedal, but assume that doesn't change much, and you can simplify it to the AH rating of the battery.
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