This is a very poorly researched article. A few things worth considering:
- 20,000 mAh is the rated capacity. Anyone who has tested 18650 batteries (which are the cells typically used in these battery packs) knows the rated capacity != tested capacity.
- Watthours is more important than amp hours
- Tested watt hours as typical loads is more important than amp hours
- It's very normal to see tested capacity to be roughly 70~80% of rated capacity.
- This commenter said they got "At 18W average, I pulled out 55.4Wh" on the Haribo [0]
- The generally considered "gold standard" for ultra light batteries in this range is the Nitecore NB20000 Gen 3, which regularly tests around 56 Wh.
So yes the conclusion is correct - you get roughly the same amount of capacity for a typical load (18W phone) for a cheaper price and slightly less weight. Very curious what battery cells the Haribo uses.
It's consumerist advertorial, which is why most of it is filler. 'Decent seeming new power bank happens to look cute' isn't that interesting of a sotry, so it has to be spun into a phenomenon that will allow the article to link out to 10 different products.
I'd go a step further and say that amp hours is meaning less since voltage is not specified. The only valid battery capacity unit of measure is watt hours.
While most battery packs use a single 3.7 lithium ion battery, Apple's first gen MagSafe battery pack used two internal batteries in series, throwing off everyone's amp hours only comparison.
Thank goodness SI units are power-of-ten based so converting between watt hours and joules is just a matter of moving the decimal place. Oh, and throwing in an ancient Sumerian constant approximating the number of Earth rotations as it revolves around the sun once.
No, Watt-second-hour = 3.6 kJ, so J to Wh is moving the decimal place couple steps AND dividing by 3.6. The actual units used in circuit designs is mAh, so the decimal has to be moved for another time then divided by 3.7[V] again. That's too much for a smooth-brained man like I am.
Yes, seconds are related to the Earth rotating around the sun. Simplifying slightly, the normal definition of a day relates to how long for Earth to rotate on its axis until the same spot on the Earth points at the sun again.
Compare Mean solar day vs Stellar day vs Sideral day - the difference is less than 5 minutes or so.
I was thinking along the lines of the ancient Sumerians arbitrarily deciding to divide 1 day into 24 hours, and 24 hours into 60 minutes, and 60 minutes into 60 seconds, and how that doesn't have anything to do with how humans came up with the concept of 1 year (the Earth rotating around the sun).
The "(gram)" make no sense here. We commonly use "kilo" as shorthand for kilogram", but kilo is just a prefix indicating 1000 and never indicates "kilogram" when given as a prefix to another unit, and so there's no implied/left out "gram" in 1 kilocalorie.
1 kilogram Calorie is the amount of energy needed to raise the temperature of one kilogram of water by 1 degree. 1 gram calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree.
I see there's some use of it after having done some searches, so I'll concede it makes some minor sense as a means to disambiguate due to the Calorie/calorie confusion. Especially as "calorie" and "gram calorie" then means the same thing. This is actually the first time I can recall having seen anyone use it, though, and so for me at least it confused matters rather than clear it up...
Though as the difference is at most 0.5%, it's probably won't affect your battery buying experience. :)
Measuring by TNT equivalent is more standardized. "This battery stores 50 grams of TNT."
Ummm, on second thought, maybe don't use that term at the airport, .. or in secure areas, ... or near the police, ... or in public, ... or on social media or anything else tapped by the NSA or other authorities.
We could also talk about lb•AU (pound Astronomical Units), but generally it's best to stick to what's standard so readers don't need to do conversions. Watt hours is great.
It's not terrible... The iPhone 17 has a battery capacity of 63 nano lb·AU. Around 16 million would equal 1 lb·AU.
Another fun one would be milli hundredweight leauge (mcwt·lg). Both hundredweight and league have multiple accepted definitions to make it more "fun". But the range maps quite nicely to everyday things:
I don't think this power bank uses 18650. You could fit 3 18650 in it, but the highest capacity 18650 out there is less than 15Wh and this advertises 77Wh. Even the tested capacity of 55Wh is higher than the before-loss 18650 capacity you could fit in it.
It's not more unnecessary than your comment about the OP article being poorly researched. If the conclusions are true, even if they didn't do the measurements themselves, I find it quite excusable to skip past the detailed specs of the battery.
yea considering they made 6 bullet points all just to say "rated and tested capacities are usually different" reeked of pedantry (although not surprising as we are on a tech site) and IMO did not warrant the label of "very poorly researched article"
you're never going to construct a lightweight pack with cylindrical (18650/21700, whatever) cells.
a real light weight battery construction isn't going to have redundant casings and fuses; it'll be the bare minimum pouch/plate style construction, the bare minimum fuses at main junctions, and as light a protective shell as can be produced to house it all in. It probably won't have a BMS of any kind on board, with the functions handled up-stream from the battery.
While that's technically true for highly specialized applications such as an F1 car such as the one you listed, the parent article is discussing USB compatible consumer battery banks. Consumer battery banks are worth building with cutting edge-but-still-mass-produced cells, multiple layers of redundancies, and integrated BMS.
"Power bank cells are mainly divided into 18650 cells and polymer cells. The most common one on the market is 18650 lithium-ion batteries, with a market share of 70%."
Although that is completely true, pretty much all discussion, speccing, and marketing of batteries and power banks is done in Ah. So the article working in that unit is logical and consistent.
The bit that annoys me always (and what makes Ah a meaningless measurement for power banks) is whether the amp-hours rating is just the internal batteries' spec summed together, or is it as measured at the 5V outlet? Huge difference!
- 20,000 mAh is the rated capacity. Anyone who has tested 18650 batteries (which are the cells typically used in these battery packs) knows the rated capacity != tested capacity.
- Watthours is more important than amp hours
- Tested watt hours as typical loads is more important than amp hours
- It's very normal to see tested capacity to be roughly 70~80% of rated capacity.
- This commenter said they got "At 18W average, I pulled out 55.4Wh" on the Haribo [0]
- The generally considered "gold standard" for ultra light batteries in this range is the Nitecore NB20000 Gen 3, which regularly tests around 56 Wh.
So yes the conclusion is correct - you get roughly the same amount of capacity for a typical load (18W phone) for a cheaper price and slightly less weight. Very curious what battery cells the Haribo uses.
[0] - https://old.reddit.com/r/Ultralight/comments/1li5rxw/20000ma...