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Comment by skavi | Hacker News Reader

Why did the mobile industry decide to use mAh instead of Wh.

Mobile Industry standardise on 3.8V, so you have two number to present to consumers, Wh or mah. Since Wh is a smaller number, marketing decided to use mah. Once that got traction, others that were previously using Wh had to follow. And now we end up having billions of consumers using mah as a unit and when they use it defaulting to 3.8V.

It is all too late now. Sigh.

I think that's just the battery industry. Whenever I shop for batteries for robotics or RC vehicles they're in mAh too.

Maybe it's slightly more convenient because the same value applies no matter how many cells are in the battery pack. So it helps distinguish the packs by electrical current output capacity which we can't get from a power value because power combines two different measures.

mAh doesn't change as you add cells to the battery pack? i'm pretty sure that's not correct.

This depends on whether they're wired in series or in parallel.

Wired in series, mAh won't change, wired in parallel, it's additive.

Most commonly RC battery packs are referred to as "1S, 2S, 3S," etc. indicating how many single cells there are in the pack wired in series. Those are also individually rechargeable via a low-current charging cable.

Yep. I'm very familiar with these from quadcopters.

The charging cable is usually called a "balance plug", because it distributes power equally to all cells instead of shoving it all through all of them in series.

My e-bike’s battery on the other hand is in Wh.

laptops are always Wh in my experience.

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