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Why your outdoorsy friend suddenly has a gummy bear power bank

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258 points arnon | 7 comments | 21 Sep 25 12:31 UTC | HN request time: 0s | source | bottom

https://archive.ph/1G2Ut
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mbesto ◴[21 Sep 25 22:58 UTC] No.45327428[source]▶
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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coin ◴[22 Sep 25 00:12 UTC] No.45327839[source]▶
> 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 ◴[22 Sep 25 00:57 UTC] No.45328092[source]▶
> 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.

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1. greesil ◴[22 Sep 25 01:37 UTC] No.45328295[source]▶
I prefer to use British Thermal Units (BTU) for my battery capacity.
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2. SV_BubbleTime ◴[22 Sep 25 04:40 UTC] No.45329138[source]▶
I use calories… then I can plan my meals and electronics together.
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3. user_7832 ◴[22 Sep 25 04:58 UTC] No.45329224[source]▶
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)

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4. eesmith ◴[22 Sep 25 07:49 UTC] No.45330312[source]▶
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.

5. vidarh ◴[22 Sep 25 08:09 UTC] No.45330449{3}[source]▶
> 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.

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6. spuz ◴[22 Sep 25 08:15 UTC] No.45330481{4}[source]▶
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.
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7. vidarh ◴[22 Sep 25 08:45 UTC] No.45330683{5}[source]▶
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...