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Why your outdoorsy friend suddenly has a gummy bear power bank

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

#181

Post by serf »

mbesto wrote: post #124

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 roug…

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...

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

#182

Post by prawn »

JohnFen wrote: post #55
heelix wrote: post #32

Earlier quoted context omitted.

The trick to lighter packs for many was weighing everything. Not uncommon to break everything down by grams - which tells you what could be improved. No point in spending $50 on a .5oz spoon, if your pack is coming in at 4lbs. Does help optimize where things could be cut and where the faf is. Lets you focus on what you really want to bring in when you have a breakdown of everything you bring. I really like lighterpac…

> Very easy to bring crap you don't need as well. This is so true it's not even funny. I keep a spreadsheet for each trip, and among other things, I record which of the items I actually used on the trips. It was very surprising to me how many things I thought I used and therefore needed, but when reviewing the records, I never (or very rarely) actually used. Those items get cut from future loads.

I'm very good at packing per my spreadsheet and then adding a few extra things at the trailhead because there's room. Mobile tripod, extra (heavy) pocket knife (just in case!), another paracord, etc.

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

#183

Post by prawn »

strken wrote: post #102
SoftTalker wrote: post #71

Earlier quoted context omitted.

I'm not a backpacker, but I presume there is stuff you normally don't use, but don't want to be without. Some amount of first-aid supplies, etc.

For me, a not-particularly-lightweight hiker with a 10kg base weight, that list includes: - a knife - a first-aid kit with some niche stuff like big gauze pads, electrolytes, strapping tape, etc. - quarter of a roll of toilet paper - a compass and whistle - a paper map - spare laces - 3L of water, unless water is guaranteed to be available (2L is more standard) - spare calories in case I'm delayed - emergency beacon…

Sometimes also wet weather gear.

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

#184

Post by eru »

xp84 wrote: post #93
nerdsniper wrote: post #67

Earlier quoted context omitted.

10 years ago most of these battery packs were relative to the 5V output voltage, so they advertised lower amp-hours. That stopped making sense with fast charging at higher voltages so they restandardized on 3.7V. But watt-hours would make infinitely more sense for all batteries.

Then the fact we’ve “standardized” on mah as the unit is just another in our long proud tradition, same reason we still use “Watts” as the main measure of light output, even when it has to be made up for use on LED bulbs.

Could as least use Coulomb (or just count electrons), instead of taking Current = Charge / Time and multiplying by charge again.

For what it's worth: 1 mAh ~ 2.25 * 10^19 electrons. Or with SI-prefixes: 22.5 exa-electrons (= 2.25 Ee).

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

#185

Post by eru »

invalidator wrote: post #137
thegrim33 wrote: post #48

Earlier quoted context omitted.

Man it drives me crazy when people/products use Ah instead of Wh as a way to specify battery "capability". Without knowing more details about the battery, "20Ah" alone does not convey enough information to determine how long the battery could power a given load for. If I need to power a 100 watt lightbulb, will a 20Ah battery power it for an hour? 10 hours? 10 days? No way to know. Wh is the unit of stored energy, Wh…

There's a technical reason for it: the voltage sags when the battery is discharged quickly. Ah is relatively constant, but Wh decreases significantly with faster discharge rates, so it can't specified as a single figure.

Is that because of internal resistance of the battery, or some other effect?

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

#186

Post by prawn »

eru wrote: post #171
JohnFen wrote: post #56

Earlier quoted context omitted.

Paper is very heavy. Even if you just carry a single map, you could likely save much of an ounce by trimming the borders.

If you are bringing your phone anyway, might as well use that for your mapping needs? You can have a backup paper map inked on your skin.

I have previously wondered about printed handkerchiefs and bandanas that functioned as backup maps. Invest in my kickstarter!

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

#187

Post by prawn »

etempleton wrote: post #16
heelix wrote: post #8

Earlier quoted context omitted.

I'll find out if this is true. Hiking buddy of mine pointed it out on Friday, so got one on the way. Was $18 when he called it out, $23 by the time I ordered. Apparently they have a bunch of random stuff like this. They must have some outdoorsy folks in marketing.

Thru hikers just kind of find this stuff. They are obsessed with weight and recommendations spread quickly through word of mouth on the trail and on forums.

And sometimes there are items that flare up and get popular before disappearing, leaving stragglers to scour second-hand lists. I remember people talking about CostCo ultralight quilts and similar.

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

#188

Post by addaon »

calmoo wrote: post #156
addaon wrote: post #84

Earlier quoted context omitted.

I'm down to around 10 lb base load. And then I hike in the desert where I carry 5 - 7 liters of water (11 - 15 lbs). And food. Saving a pound here and there is totally worth it, but there's a large part of the country where prudent hiking means the majority of your weight is water.

Out of curiosity where in the desert do you hike and where would you recommend? I have a particular attraction to being in the American desert but never have hiked it properly.

I live in southern Utah, between Zion, Bryce, and the Grand Canyon, right next to Escalante. There's plenty of stuff within a day's drive of here; previously mentioned, plus Canyonlands, Capitol Reef, Arches, and all the state parks, national forests, etc.

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

#189

Post by heelix »

SoftTalker wrote: post #71
JohnFen wrote: post #55

Earlier quoted context omitted.

> Very easy to bring crap you don't need as well. This is so true it's not even funny. I keep a spreadsheet for each trip, and among other things, I record which of the items I actually used on the trips. It was very surprising to me how many things I thought I used and therefore needed, but when reviewing the records, I never (or very rarely) actually used. Those items get cut from future loads.

I'm not a backpacker, but I presume there is stuff you normally don't use, but don't want to be without. Some amount of first-aid supplies, etc.

I do pack in a small med kit. Typically 3-4 Advil, a couple aspirin, tylenol, a tums, one anti-diarrhea, and one sudafed (meth grade). I also bring in a couple waterproof bandaids, a single serving antiseptic, and a small square of leukotape. Most of that never gets used, and is packed over and over. You can spot the med kit in this picture in a small pill pouch.

https://imgur.com/N5en41d

I'll pack in a second mini-bic. One that stays in my pocket, one for our group to constantly loose throughout the trip. Same for that extra TP packet. I'd rather have it with, then find myself in the woods running short. Got a whistle in there too that I don't think I've ever used on the trail.

Most of my hikes, I'll plan to be at the site before dark. I'll still bring a reasonable headlamp.

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

#190

Post by rhinoceraptor »

Ekaros wrote: post #24
JohnFen wrote: post #6

Earlier quoted context omitted.

If you're taking a shaving device of any sort on your backpacking trip, you've missed a core lesson of the ultra light dudes.

Wouldn't it be logical that ultra light people have no body hair left? And want to keep it so? After all that is lot of grams...

Not to mention all the energy loss from air friction!
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