Volts, amps, watts, amp-hours, watt-hours, and miliamp-hours?
What does all this mean? As I often struggle to understand these terms myself, I thought I’d do a post for all of us.
Most e-bike batteries are described in voltages that are increments of 12.
I mainly deal with 36, 48, and 52 volt batteries. For background, here is an explanation of watts, amps, and volts from the TechQuickie YouTube channel.
Battery pack capacity is measured in Watt-hours and Amp-hours. The terms Watt-hours and Amp-hours are measurements of electricity over time. My e-bike system might be designed to deliver 30 amps under when under full power climbing a very steep hill, but then drop back down to a much lower level when heading downhill. The amp-hour rating and watt-hour rating refer to the capacity over time. Your stock BionX 48 volt battery with an 8.8 amp-hour battery will supply an average of 8.8 amps of current to power they system continuously for one hour until it is depleted and the battery management system shuts the systems off to protect the battery from damage. The 432 amp-hours that it carries will sustain 432 amps continuously for one hour. Another measurement in battery ratings has to do with the individual capacity of each battery cell.
The Bionx 48v system came with four 2200mAh hours that are connected together in a group of 4. That means 2200 milliamp-hours gets multiplied four times. Because there are 100 Milliamps in one amp, that means 2.2 x 4 = 8.8 amp-hours. I use 3500 mAh cells and replicating the same structure of 4 cells in parallel means 3.5 x 4= 14 amp-hours.