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Devices don't say "It needs 40Wh battery" Devices say "it needs AA battery" or "It needs 18V battery" >W/H is insufficient for describing batteries unless you
by ilyt 3y ago
Devices don't say "It needs 40Wh battery"
Devices say "it needs AA battery" or "It needs 18V battery"
>W/H is insufficient for describing batteries unless you specify the voltage you are working with.
Yes. Then do exactly that. Describe Wh and voltage.
- pas 3y agoJust describe Joules. No need to bring hours into it.
- vel0city 3y agoNot everyone likes to think about how many seconds their devices will last. Hours are a lot easier to reason about.
- firebat45 3y agoThere are two important numbers when it comes to batteries. Volts and Amp/hours. Watt/hours is simply a calculated value. Why provide watt/hours and force people to back-convert to amp/hours? Watt-hours is only useful when comparing batteries of different voltages, which is not a very practical thing to be doing. For batteries of the same voltage, amp/hours is a simpler and easier way to compare.
- stetrain 3y agoWhat voltage is your laptop battery? Your smartphone battery? Your Anker power bank battery? What voltage are they outputting over USB-C PD? The Volts and Amp-hours (not amp/hours) metrics make sense when comparing raw battery cells, but when integrated into a device where the voltage is unknown or variable output for charging different devices, it becomes less relevant. Watt-hours tells you the total energy. A laptop with more Watt-hours has more battery than one with fewer Watt-hours, all in a single unit without needing to multiply things together.
- ilyt 3y ago>Why provide watt/hours and force people to back-convert to amp/hours? Because you don't use amp-hours for ANYTHING. If you have battery and want to know how long your 3.3V device will run from it, the simplest way to do it is to just measure power your device uses and compare it with Wh of battery. Doesn't matter whether input is single 3.7V battery or 18V battery pack, all you care for is your device power usage and your power supply efficiency at that voltage. > For batteries of the same voltage, amp/hours is a simpler and easier way to compare. It's not simpler and it's exactly as easy to compare, bigger number is better...