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).
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.
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.
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.
> 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.
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.
> 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.
> 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.
> 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?
Consumers do not know the amp-hour capacity of coin cells or AAA batteries. They don't know and they don't care. Consumers put a coin cell into an AirTag and come back a year later to replace it when their iPhone tells them to. They don't care about the capacity. It's not relevant to this discussion at all. The percentage of consumers who care about the capacity of those types of batteries is certainly tiny.
> 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.
It is not more convenient, since consumers do not think about <1Ah values, virtually ever.
> 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?
And I repeat: We could represent all distances in millimeters just in case, but we don't.
LA is only 4,506,163,000 millimeters from NYC. Very convenient.
> Consumers do not know the amp-hour capacity of coin cells or AAA batteries. They don't know and they don't care. Consumers put a coin cell into an AirTag and come back a year later to replace it when their iPhone tells them to.
Then why label batteries with a capacity at all, if consumers don't care so much?
They care when they're buying batteries and they have a choice of different ones to buy.
> It is not more convenient, since consumers do not think about <1Ah values, virtually ever.
Even if that were true, it doesn't justify changing the customary unit.
> And I repeat: We could represent all distances in millimeters just in case, but we don't.
> LA is only 4506163000 millimeters from NYC. Very convenient.
And people could report their height in meters, yet they frequently use centimeters.
Among other things, we don't use millimeters for long distances because 10-digit numbers tend to be an awkward number of digits to work with, but 4 or 5 digits are still pretty easy and natural to work with. I wonder how many digits the LA to NYC distance is in kilometers? Well, wouldn't you know it, it's 4.
Anyway, this conversation isn't going anywhere. Batteries will continue to be labeled in mAh, even if you have a strong personal opinion that everyone else is using the wrong prefix thousands of companies and millions of people just need to switch to Ah now.
We label batteries with capacity in cases where said capacity is tiny compared to user's needs. It allows user to guesstimate if their phone will last 1 or 2 days on a single charge.
For AAA batteries, which in typical use last at least several months the exact capacity number becomes largely irrelevant.
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).