How big of a battery do I really need?
Which spec tells me the battery capacity?
These three are the most common ones: volts, amp-hours, and watt-hours.
Watt-hours (again, thats Wh) are the most useful unit when it comes to energy capacity.
Assuming honest specifications, the bigger the watt-hour rating, the bigger the battery longer the range.
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Finding a batterys watt-hour rating from volts and amp-hours is the simplest of multiplications.
Heres the formula for you:
Wh = Ah * V
Thats it.
Or divide the watt-hours by amp-hours to find the voltage.
Keep in mind the above formula is an approximation, as a batterys voltage will vary during use.
The ebike Im looking at has a 250W motor.
How does that relate to range?
The motors wattage on its own doesnt tell you anything about the range.
Although they are related,wattsare distinct fromwatt-hours.
The former is a unit of power.
A higher-wattage motor higher-wattage motor can theoretically go faster or climb up steep hills for longer.
The figures given by manufacturers are averages.
The watt-hour, on the other hand, is a unit of energy (or energy storage).
But again, you shouldnt rely on watts to estimate range because the motors wattage is rarely constant.
How big is big?
Typical ebike and scooter batteries tend to hover around the 400-600Wh mark.
How far those batteries will take you depends largely on how you use your bike or scooter.
Lots of talk about watts, but what about volts and amp-hours?
Still, you might be curious how volts and amp-hours come into play.
It can be a little confusing, so keep in mind the following is all a simplification.
On the other hand, higher voltages can technically increase the risk of electrocution.
Thats partly why you rarely see commercial ebikes go beyond 52V.
As with so many facets of technology, the implementation often matters more than the actual specs.
In my experience higher voltage batteries areusuallybetter than lower voltage ones.
Despite remaining a common specification, amp-hours is frankly a pretty useless metric for most ebike and scooter riders.
A 24V 20Ah battery will have significantly less range than a 52V 15Ah one.
