[dgacmu]

I 99.9% agree with you. Some nitpicks, since this is a discussion of getting units right:

mAh doesn't measure "current", because current is the flow of electrons. It measures charge.

2000 mAh hour is redundant - the 'h' in mAh is hours. :)

But your basic point is 100% correct: All batteries should show their capacity in Wh.

[coder543]

It's also redundant because with 2000mAh... "thousand milli" can just be eliminated, leaving us with 2Ah.

Everyone constantly referencing thousands of thousandths is another one of my "favorite" things about the industry using mAh as a standard measurement of battery "capacity" (besides the fact that they almost never specify voltage or watt-hours).

[maxnoe]

Don't quote capacity. It is the correct tern, physically. Capacity is the amount of electrical charge something can store, Ah is unit of that. Not the natural unit though, that would be Coulomb (C).

Why use Charge and not energy? Because the voltage changes as the battery is discharging, so it's not as straight forward as just multiplying with the voltage.

[coder543]

> It is the correct tern, physically.

Agreed, but not from a consumer perspective, where it is very confusing that a battery with half the capacity might have twice the energy due to differences in voltage.

From a consumer perspective, the battery capacity is the amount of energy, regardless of whether that is wrong.

[TT-392]

I don't think "capacity" neccesarily has a concrete unit connected to it. I am pretty sure you could call both the charge and the energy in a battery its capacity.

[paholg]

> Not the natural unit though, that would be Coulomb (C).

To be pedantic, you mean SI unit. The natural unit of charge is the electron (e).

[tivert]

> It's also redundant because with 2000mAh... "thousand milli" can just be eliminated, leaving us with 2Ah.

But then you'd have to do more conversions when comparing. I've seen batteries with capacities as low as 10mAh. 4 digits is still a reasonably practical number.

[coder543]

In the consumer space, virtually no battery I've seen in more than a decade is less than 1000mAh. If you looked at the Reddit post, you know we're talking about laptops, tablets, phones, external power banks, that type of consumer-facing application. But, even then, converting is fine. People understand there are 1000 meters in a kilometer. I don't think any of this is rocket science.

However, outside of the consumer space... doing conversions like that is also fine. When browsing DigiKey, components are often listed in the optimal unit prefix. When necessary (not so much with batteries), the interface allows you to filter based on ranges you provide, and it will perform the necessary conversions for all the products to give you an accurate list.

[tivert]

> In the consumer space, virtually no battery I've seen in more than a decade is less than 1000mAh.

Behold:

https://www.amazon.com/Panasonic-BK-4MCCA4BA-eneloop-Pre-Cha...

https://www.amazon.com/PANASONIC-BATTERIES-CR1216-LITHIUM-BA...

https://www.amazon.com/SR521W-SR521SW-LR521-Alkaline-Battery...

> People understand there are 1000 meters in a kilometer. I don't think any of this is rocket science.

Yes, but it's one more mental operation, and every mental operation like that is relatively costly. People don't actually have that many slots of working memory. You are optimizing to minimize digits, which is probably the wrong thing.

[coder543]

>> virtually no battery

> Behold <a single counterexample that is far less commonly encountered by consumers than phones, tablets, laptops, or external power banks>

EDIT: Ok, now you have updated your comment to also include coin cells, which is even less relevant. This just shows you don't appreciate what we're talking about here.

Consumers care about the amp-hour capacity of larger devices for various reasons. They need to figure out how many times they can recharge a phone from an external power bank. They want to understand how much less efficient their laptop is than their tablet. That's not what they do with coin cells or AAA batteries.

You have also ignored that we can express 0.8Ah. It doesn't have to be 800mAh vs 2Ah. Since things less than 1Ah are far less common for consumers, it would be logical to just show everything in Ah, and then represent those smaller things as fractional Ah, if we're afraid of multiplying and dividing by 1000.

We could represent all distances in millimeters just in case, but we don't.

[tivert]

> Behold <a single counterexample that is far less commonly encountered by consumers than phones, tablets, laptops, or external power banks>

People still use AAA batteries, and that probably the most well-known, premium brand of rechargeable AAAs.

> Consumers care about the amp-hour capacity of larger devices for various reasons. They need to figure out how many times they can recharge a phone from an external power bank. They want to understand how much less efficient their laptop is than their tablet.

But they do care about the metric prefix? mAh far more established and slightly more convenient to use than Ah for these kinds of batteries.

Edit:

> You have also ignored that we can express 0.8Ah. It doesn't have to be 800mAh vs 2Ah. Since things less than 1Ah are far less common for consumers, it would be logical to just show everything in Ah, and then represent those smaller things as fractional Ah, if we're afraid of multiplying and dividing by 1000.

I haven't ignored that, it's just not a very appealing thing to do and doesn't answer any of the problems with switching the customary prefix.

Yes. It would be possible to relabel all consumer batteries with Ah instead of mAh, but why would anyone want to go through all that trouble?

[out_of_protocol]

> They need to figure out how many times they can recharge a phone from an external power bank.

Watt-hours to the win! No more 10'000 mAh at 5V (nope, it's 3.7V) weirdness

[Izkata]

How about Apple Airpods then? I've found 43.24 mAh and 49.7 mAh depending on the version.

[hulitu]

> "thousand milli" can just be eliminated, leaving us with 2Ah.

They call it marketing.

[Joker_vD]

Have you ever heard the word "half-pair"?