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Discussion Starter #1
I was curious about the practical relationship between voltage and top speed but I didn't know how to test it, everyone usually says voltage = top speed but can you draw something more concrete than that? Then I realised that the EV album has the voltage and speed data for a whole bunch of vehicles, why not just take a sampling and see if there is a correlation. So here are the results of a sampling of 40 normal sized cars and pick-ups using flooded lead acid batteries and DC motors:


As you can see there is a pretty linear upward trend. My conclusion based on a line of best fit with an accuracy of plus or minus 20% (with the variation probably due to vehicle size) is this: Your top speed will be a third of your voltage plus 30mph.
i.e.Top Speed = (Voltage)/3 +30
 

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Discussion Starter #3
Yeah as I said I worked it out with Flooded LA and DC, but there was 1 144V EV that peaked at 96mph... ;)It wouldn't be impossible
 

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Discussion Starter #5
Well higher voltages also mean more efficiency (less heat losses in the resistive loads eg. wires), more power capabilities and as long as you don't also reduce the Ah rating it usually means more energy which means more range. It will also cost more and be slightly more dangerous.

I don't know if its wiki material seeing as the accuracy is way out its +-10mph at the lower end and +-15 at the top end, maybe if I just followed one vehicle size it would be a closer grouping...
 
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