Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why your outdoorsy friend suddenly has a gummy bear power bank

theverge.com

Post reply on HN
Print view View original

261–270 of 327 posts

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#261

Post by eesmith »

greesil wrote: post #192
nwallin wrote: post #170

Earlier quoted context omitted.

> 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.

I prefer to use British Thermal Units (BTU) for my battery capacity.

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.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#262

Post by dmos62 »

ics wrote: post #143
trenchpilgrim wrote: post #136

Earlier quoted context omitted.

I spent time in India as a kid sleeping on the hard floor of my grandmother's home. Maybe my sense of comfort is different IDK, but I don't consider a pad essential on a warm night

I’m from the US but a “floor sleeper” and have never camped with a pad like these even in near-freezing temperatures. I’m sure it helps but these days I get the impression from people around that they just like gear, don’t like being uncomfortable, and any other benefit is just a bonus to rationalize spending money. Maybe I’ll try it some day and be a convert, until then…

You sleep on the ground in near-freezing temperatures? That's impressive, if true. I find it difficult to sleep if I lack insulation from the ground. An air-mattress isn't enough for me when it's 10-12 degrees celcius outside, provided my 20 yo sleeping bag is not meant for these temperatures.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#263

Post by dmos62 »

Fricken wrote: post #146
ashdksnndck wrote: post #127

Earlier quoted context omitted.

That the purpose of the sleeping pad is characterized as thermal performance and not comfort is proof that I am not capable of the ultralight mindset.

With ultralight activities you're supposed to be so exhausted by bedtime that it isn't necessary to be comfortable to fall asleep.

Hypothermia helps with exhaustion too.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#264

Post by shlant »

n2d4 wrote: post #246
mbesto wrote: post #217

Earlier quoted context omitted.

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.

> 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.

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"

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#265

Post by vidarh »

user_7832 wrote: post #238
SV_BubbleTime wrote: post #235

Earlier quoted context omitted.

I use calories… then I can plan my meals and electronics together.

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 )

> 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.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#266

Post by spuz »

vidarh wrote: post #265
user_7832 wrote: post #238

Earlier quoted context omitted.

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 )

> 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.

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.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#267

Post by shmeeed »

bschwindHN wrote: post #145
codedokode wrote: post #15

Sorry for being off-topic, but why with all the advanced technology today I have to manually copy ounces and pounds into Google to learn how much it is? Instead of adding dark themes and material design, it would be better to add a unit converter. Also do you really need a power bank for a 2-day trip? In airplane mode a phone can live like 2 weeks.

On iOS: Highlight text, select convert, see conversion: https://imgur.com/a/tD9H1t9 But the real solution is for Americans to stop using dumb units.

On Pixel and Samsung:

Long press home button for "circle to search", draw line across text, see conversion.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#268

Post by masklinn »

beAbU wrote: post #250
masklinn wrote: post #241

Earlier quoted context omitted.

> 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.

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!

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.

Re: Why your outdoorsy friend suddenly has a gummy bear power bank

#270

Post by draven »

Fricken wrote: post #146
ashdksnndck wrote: post #127

Earlier quoted context omitted.

That the purpose of the sleeping pad is characterized as thermal performance and not comfort is proof that I am not capable of the ultralight mindset.

With ultralight activities you're supposed to be so exhausted by bedtime that it isn't necessary to be comfortable to fall asleep.

If you don't have a minimum of comfort you'll have a bad night and wake up exhausted the next day.
Post reply on HN