| ▲ | mbesto 3 days ago |
| 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. [0] - https://old.reddit.com/r/Ultralight/comments/1li5rxw/20000ma... |
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| ▲ | anigbrowl 3 days ago | parent | next [-] |
| 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. |
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| ▲ | coin 3 days ago | parent | prev | next [-] |
| > Watthours is more important than amp hours 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. |
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| ▲ | nwallin 3 days ago | parent | next [-] | | > The only valid battery capacity unit of measure is watt hours. I would also accept Joules. But yes, the unit should be a unit of energy. | | |
| ▲ | beAbU 3 days ago | parent | next [-] | | You are probably making a joke, but just in case and for those that don't know, a joule _is_ a watt hour. 1 joule is 1 watt-second to be precise. So 1Wh is 3600 joules. | | |
| ▲ | numpad0 3 days ago | parent [-] | | So that's why it doesn't align with existing industry units and always requiring conversions... | | |
| ▲ | bregma 3 days ago | parent [-] | | 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. | | |
| ▲ | numpad0 3 days ago | parent | next [-] | | 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. | |
| ▲ | lotsofpulp 3 days ago | parent | prev [-] | | Do seconds have anything to do with the Earth rotating around the sun? I thought a second just has to do with the Earth’s rotation on its axis. Also, I wonder how usable a unit of time that was not based on a day would be, since so much of our life revolves around that cycle. | | |
| ▲ | tnlnbn 3 days ago | parent [-] | | 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. | | |
| ▲ | lotsofpulp 3 days ago | parent | next [-] | | Thanks, I see now from: https://en.wikipedia.org/wiki/Solar_time 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). | |
| ▲ | 3 days ago | parent | prev [-] | | [deleted] |
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| ▲ | greesil 3 days ago | parent | prev | next [-] | | I prefer to use British Thermal Units (BTU) for my battery capacity. | | |
| ▲ | SV_BubbleTime 3 days ago | parent | next [-] | | I use calories… then I can plan my meals and electronics together. | | |
| ▲ | user_7832 3 days ago | parent [-] | | I know it's a matter of taste but personally I prefer to use the Calorie instead of the calorie ;) (Context: 1 Calorie = 1 kilocalorie = 1000 (gram) calories; https://en.wikipedia.org/wiki/Calorie) | | |
| ▲ | vidarh 3 days ago | parent [-] | | > 1000 (gram) calories 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. | | |
| ▲ | spuz 3 days ago | parent [-] | | 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. | | |
| ▲ | vidarh 3 days ago | parent [-] | | 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... |
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| ▲ | eesmith 3 days ago | parent | prev [-] | | Today I learned there are multiple BTU definitions. https://en.wikipedia.org/wiki/British_thermal_unit lists Thermochemical, 59 °F, 60 °F, 39 °F, and International Steam Table. 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. |
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| ▲ | macrocosmos 3 days ago | parent | prev [-] | | 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. | | |
| ▲ | fy20 3 days ago | parent [-] | | 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: AA battery - Around 5 mcwt·lg Phone battery - Around 20 mcwt·lg Laptop battery - Around 200 mcwt·lg Car 12v battery - Around 1,000 mcwt·lg EV battery - Around 100,000 mcwt·lg |
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| ▲ | sixothree 3 days ago | parent | prev [-] | | The package says 3.85v so certainly this is a lipo. |
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| ▲ | tredre3 3 days ago | parent | prev | next [-] |
| 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. > This is a very poorly researched article So, yeah, pot, kettle, all that. |
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| ▲ | mbesto 3 days ago | parent [-] | | I think you're right, however, 18650 batteries do carry, on average, more energy density per volume and weight. > but the highest capacity 18650 out there is less than 15Wh and this advertises 77Wh. 10x 2000 mAh 18650 batteries in parallel gives you 20 Ah @ 3.7V. > So, yeah, pot, kettle, all that. Totally unnecessary comment but thanks. | | |
| ▲ | n2d4 3 days ago | parent [-] | | > Totally unnecessary comment but thanks. 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. | | |
| ▲ | shlant 3 days ago | parent [-] | | 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" |
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| ▲ | serf 3 days ago | parent | prev | next [-] |
| 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. here's something close, although with plenty of weight compromise for reliability and safeties' sake. : https://global.honda/en/tech/motorsports/Formula-1/Powertrai... |
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| ▲ | lelandbatey 3 days ago | parent [-] | | 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. |
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| ▲ | harrall 3 days ago | parent | prev | next [-] |
| A lot of battery packs do not use 18650s but rather pouches, which are a lot smaller at the cost of some stability. |
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| ▲ | emilfihlman 3 days ago | parent | prev | next [-] |
| >18650 batteries (which are the cells typically used in these battery packs) Absolutely not. Pouch cells are what most powerbanks have. |
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| ▲ | masklinn 3 days ago | parent | prev | next [-] |
| > Watthours is more important than amp hours 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. |
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| ▲ | beAbU 3 days ago | parent [-] | | 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! | | |
| ▲ | masklinn 3 days ago | parent [-] | | I would assume it’s whichever gives the highest number which is usually going to be the internal voltage. For instance I have a 20000mAh power bank which also has a 74Wh capacity printed on, a conversion factor of 3.7V matching li-ion chemistry. Not to mention with PD neither the neither input not output voltages are limited to 5V. |
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| ▲ | 1oooqooq 3 days ago | parent | prev | next [-] |
| you don't have to go that far. probably that demographic won't even carry a power bank to begin with. |
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| ▲ | mrheosuper 3 days ago | parent | prev [-] |
| typical li-po pouch, bet it's 2*10Ah pouch connected in parallel. |
