[HN Gopher] This site is no longer solar powered for now
___________________________________________________________________
This site is no longer solar powered for now
Author : adriangrigore
Score : 194 points
Date : 2023-06-03 16:04 UTC (6 hours ago)
(HTM) web link (www.andrewjvpowell.com)
(TXT) w3m dump (www.andrewjvpowell.com)
| dbg31415 wrote:
| I'm sure Optus appreciates the brand mention! =P
| HotGarbage wrote:
| Leaving hotspots connected via USB 24/7 is a no-no, and people
| put some effort trying to run them without a battery:
|
| - https://www.eevblog.com/forum/repair/trick-the-hotspotphone-...
|
| - https://jibout.com/verizon-7730l-mifi-hotspot-battery-bypass...
|
| - https://old.reddit.com/r/Calyx/comments/lorkrv/running_mifi_...
|
| I feel like there's some liability on Netgear's part here: People
| can't be expected to know they can't leave it connected and a
| charging circuit should not constantly feed the battery.
|
| It's a shame there aren't more affordable connectivity options
| for projects like this. Hotspots with batteries tend to be a lot
| cheaper than battery-less routers and USB dongles. The latter of
| which isn't even available for 5G.
| wrs wrote:
| This just seems like a ridiculous consumer-safety violation.
| How is it legal to sell these things?
| akira2501 wrote:
| > It's a shame there aren't more affordable connectivity
| options for projects like this.
|
| There's tons of options, and the "professional" grade routers
| aren't much more expensive than that consumer grade AC800s.
| With the one I have I get a removable SIM, dual SMA antenna
| connectors for MIMO with the ability to have an external high
| gain antenna, 5 ethernet ports, and a box that runs a version
| of ddWRT that I have full control over.
|
| The AC800s is $200, my modem was $350.
| HotGarbage wrote:
| Used hotspots are $20 on eBay. The Franklin T9 is hackable
| and fun, but it would be nice to have Ethernet and OpenWRT
| for less than $100
| leohart wrote:
| Oh? Any links?
| j45 wrote:
| It might be better to buy a USB modem instead of a hotspot.
|
| Rocket sticks come to mind.
| worldofmatthew wrote:
| In the UK, USB 4G LTE adapters are cheaply available 2nd
| hand. Plug that into a SBC and away you go.
| bityard wrote:
| I have a battery powered hotspot from my provider. Like a
| phone, it refuses to run off usb without a battery installed.
| But it yells at you and shuts down when plugged in for too
| long. I need to have it online all the time.
|
| I "fixed" it by plugging the charger into an old school
| mechanical timer. Every six hours, it runs off the battery for
| 30 minutes. Has been working great for 2 years.
| Nextgrid wrote:
| > charging circuit should not constantly feed the battery
|
| To me this seems like a common misconception. I can't see it
| being true - we'd see so many more battery fires out there if
| this was true, including in this very case (his setup would've
| burnt down within days in that case).
| hattmall wrote:
| It's not likely to cause a fire but it will ruin the battery.
| Generally it causes swelling which physically damages the
| charging connection.
| aloer wrote:
| Why is that such a problem if it's apparently fine to keep
| phones and other small devices connected 24/7? Aren't charging
| circuits standard parts? I would have expected them all to work
| more or less the same
| hattmall wrote:
| It's not fine unless it has protection built in which is
| rare. After a few years battery will swell.
|
| I wrote a script that scrapes the hotspot web interface to
| turn off a smart plug when it's at 90% and turn back on at
| 60%.
| latchkey wrote:
| I run a NetGear M5 in my campervan. It has a battery that is
| charged with the solar on the van. The thing gets stupid hot and
| I'm always afraid it is going to combust. I just leave the back
| cover off of it and put a fan on it, and that seems to help.
| fzeindl wrote:
| > External power was never quite enough, with enough activity the
| thing was liable to randomly reboot.
|
| Maybe there was a fault in the circuitry to begin with.
| Avamander wrote:
| Unfortunately the Pi-s, especially the 4 and 3, have really
| finicky power circuitry. That lack of robustness combined with
| your usual SD-cards that can't handle it either is in my
| opinion one of the worst aspect of the Pi-s.
|
| https://hackaday.com/2021/02/12/pcb-mods-silence-voltage-war...
| Brybry wrote:
| I think the article was saying the issue was the Netgear
| AC800S 4G/Wifi[1] modem rebooting if it didn't have its
| removeable battery inserted.
|
| I believe the RPi and the car battery they were using are
| still fine.
|
| [1] https://www.netgear.com/images/datasheet/mobile/ac800s_op
| tus...
| ElongatedMusket wrote:
| This post reminds me of the pre-steam days of gaming servers when
| certain clan members with fat pipes would host servers out of
| their homes or after-hours business racks, and often have little
| blog posts like this on their PHP-Nuke clan website or in-game
| MOTD, containing whatever little peril the admin had to deal with
| hosting the server... from kids tripping on wires to rats nesting
| in the chassis, it was always fun to read.
|
| When resources are scarce, interesting stuff happens. Nowadays
| most outages are either due to expired payment, disk full, or
| provider outage. That's a good thing I guess? Just much less fun.
| shadowgovt wrote:
| I remember back in the day when the something awful forums went
| down for a while because of hurricane Katrina.
|
| They had a message up for a while that said they were
| unavailable because their servers were either underwater, or on
| the back of a looter's truck that was itself underwater.
| selimthegrim wrote:
| Their colo was on Poydras St in downtown NOLA.
| ericbarrett wrote:
| When I was young I ran a Team Fortress Classic server from my
| living room. It was hooked up to 768k SDSL (symmetric). It was
| 2fort-only--still a common thing in TF2--and popular enough
| that it was full 24/7, with a 20 player limit. Had lots of
| regulars, some of whom stayed in touch for years afterward.
| Some of the things that caused downtime:
|
| The house's floor slab had a crack that wicked up groundwater
| when it rained too much, so my carpet would get mushy.
| Electronics off!
|
| The anti-cheat software I ran (PunkBusters) went crazy after an
| update and banned anybody who connected. I noticed when my MRTG
| graphs flatlined.
|
| Girlfriend once yanked out the Ethernet cable when we were
| having adult time. I didn't bother explaining that one to the
| players.
|
| Heavy web browsing would cause lag, so I ended up learning how
| to do QoS via iptables (or its precursor, whose name I forgot).
|
| At the time, the server used an astonishing _25 gigabytes_ of
| bandwidth a month. Always raised an eyebrow with the ISP tech
| when I called in, but they never complained.
| wes-k wrote:
| TFC! I ran a TFC concing server from my college dorm back in
| 2004/2005. Been dreaming of setting up my old PC to play
| again.
| ShroudedNight wrote:
| I miss TFC. I remember learning how to conc-jump with the
| medic and figuring out the detonation points for pyro, and
| ultimately getting to the point where my presence was
| materially beneficial to my team. I never managed to get
| there in TF2; they had (at least at first glance - I presume
| the meta simply changed) blunted the ability of a single
| player to significantly move objectives forward. I had
| already been burnt by the changes between Day of Defeat, and
| DoD: Source, and the TF2 changes seemed to confirm that I was
| simply not a member of the target audience for the Source
| remakes.
| Tool_of_Society wrote:
| Dude I was a double conc jumping master. Then they
| destroyed conc jumping and other fun stuff :(
| ElongatedMusket wrote:
| You might enjoy playing Junkrat in Overwatch 2 if you like
| pyro. I skipped TF2 (the playful paintbrush texture were a
| turn-off at the time) but now 10 years later some of the
| OverWatch characters give me the same joy to play I had in
| original TFC (sniper=Widowmaker, medic=Mercy,
| soldier=Pharah, spy=Sombra)
| Tool_of_Society wrote:
| I was just thinking that Junkrat's bomb reminded me of
| stuff I used to do in TFC.
| dizhn wrote:
| ipchains
| [deleted]
| [deleted]
| duxup wrote:
| My DSL line hosted so much quake except when I needed to do
| something else...
|
| So did my work computer;)
| midasuni wrote:
| Less fun, and more common.
| thathndude wrote:
| Agreed. Feel like there's a proper life lesson in here about
| enjoying the difficulties and embracing the journey. The
| destination might get a bit boring.
| CydeWeys wrote:
| The holy grail was always someone at a university with a 100
| Mbps connection. That was godlike back in the day when most
| people still had 56k dial-up and the lucky people had ADSL
| which was, iirc, 768 Kbps.
| MandieD wrote:
| 56k dialup? Luxury!
|
| 1200 bps Unix shell access from TENet (Texas Educators'
| Network) - thank you, Mr. Horner, my 9th grade US History
| teacher, for telling that nerdy girl who turned in all her
| papers in dot matrix print about what she could get her
| mother, a fellow teacher, to pay all of $5/year for.
|
| Oh, and daring to have us look at Reconstruction's sudden
| cut-off, Jim Crow and the fact that we were less than 30
| years from its legal end in Texas, the Bonus Army, our rather
| late entry into WW2, the Japanese-American internment camps,
| and various shenanigans to do with the Vietnam War - you
| taught us that it's possible to both love your country and to
| accept that it is by no means perfect.
|
| I hope you're enjoying a good retirement.
| felipemnoa wrote:
| >>Bonus Army
|
| I have tiny recollection of this this but thanks to your
| comment I became acquainted with it again.
|
| Thanks!
| leereeves wrote:
| > the lucky people had ADSL which was, iirc, 768 Kbps.
|
| I still have ADSL. It's now 5 Mbps, but I don't recall what
| it was when dial up was common.
| InvaderFizz wrote:
| 144kbps(IDSL, actually ISDN), 384kbps, 768kbps, and 1.5mbps
| were incredibly common speeds during the early days and
| especially not in major cities. I was on dialup in BFE,
| switch to 64k ISDN in 97/98, and cable came alone at a
| whopping 3mbps in 99, complete game changer.
|
| Higher speeds of DSL came along with ADSL2 in 2002/2003.
| There were higher than 1.5mbps before that, but you
| basically had to be across the street from the CO to get
| that.
| dylan604 wrote:
| I grew up in a small town that Europeans would have a
| hard time calling it a village. We were too far away from
| a CO to get DSL even with repeaters. No cable provider
| wanted to bring us service either as there were not
| enough people to ever recovering the expense of stringing
| the lines. The best I ever had while living there was
| 33.6k using a 56k modem
| mrighele wrote:
| When first ADSL came out in my country, the speed was about
| 256Kbps; 758Kpbs arrived only a few years later
| mauvehaus wrote:
| Where do you live?! I thought we had it bad with 15Mbps
| ADSL in rural Vermont. YouTube and Netflix are surprisingly
| tolerable as long as only one person is watching. How is it
| for you at 5?
|
| Do you get cell service? We don't and that's actually the
| bigger hassle. Wi-Fi calling is kind of shit, and the
| coverage outside the house is appallingly unreliable.
| iMessage is frustratingly unreliable too. I'll be on Wi-Fi,
| but it won't have gotten synched up with Verizon and it'll
| refuse to send a message until it does.
| leereeves wrote:
| At 5 Mbps, YouTube only works up to 720p. I assume
| streaming is the same but haven't seen one that reports
| the current resolution.
|
| We do have cell service. We're in an older 1950s
| development that was never rewired, but not far from
| newer developments.
|
| The biggest problem for me is that downloads keep getting
| bigger and bigger. The latest AAA games are almost 100 GB
| and take days to download.
| charrondev wrote:
| Have you considered Starlink? You should be able to get a
| ton more bandwidth there.
| hattmall wrote:
| All 3 of the major carriers have unlimited plans that
| would far outpace your DSL.
| bradknowles wrote:
| The GP may well only have 4G/LTE available, not the
| faster 5G/fixed wireless. In our neighborhood, the
| 5G/fixed wireless stuff is not yet available from
| T-Mobile or Verizon, only 4G/LTE.
|
| And either way, even that coverage is spotty and speed
| varies highly on the time of day that you're trying to
| use it.
|
| All this is fine for a tertiary backup solution (behind
| Starlink) but not as a primary method of accessing the
| Internet.
| izacus wrote:
| The initial rollout in my country was 512kbps/128, which
| later got slightly bumped to 1024/128.
|
| That was the default speed for a long time.
| time0ut wrote:
| I moved into the dorms with two computers: a gaming laptop
| circa 2001 and a cheap AMD Duron based box running Linux and
| the counterstrike server software. Good times.
| lrem wrote:
| It's not like the fun of animals nesting in your expensive
| equipment went away. You are simply paying for someone else to
| experience that.
| PragmaticPulp wrote:
| Learning the difficulties of self-hosting is a rite of passage
| for tech minded people.
|
| It seems nearly everyone goes through a "How hard can it be?"
| phase where self-hosting seems like it will be a trivial way to
| save a lot of money. Then you get to learn about all of the
| things that can, and will, go wrong over time. Great learning
| experience.
|
| And then there are the rose-colored glasses people who seem to
| forget all of the troubles they go through with self-hosting. A
| few companies back we had a guy who insisted on self-hosting
| some things on premises to save on SaaS costs. The amount of
| time we spent waiting for him to figure out why the server was
| misbehaving each week easily cost several times more than any
| hypothetical savings. Yet when you ask him, he'd claim it was
| virtually hassle-free. Management liked it because it "saved a
| lot of money"... as long as you ignore the cost of the time we
| lost to dealing with it.
| api wrote:
| Where I always go with this is to ask why our software is so
| damn horrible that it requires this much babysitting. Self
| hosting could be trivial if our software wasn't slop.
|
| I wonder how much we spend babysitting slop (either directly
| or indirectly through SaaS) vs how much it would cost to
| invest in engineering around automated and reliable
| deployment and resilient software?
|
| Highly polished distributed file systems, databases, and
| orchestration tools that incorporated automatic replication
| and fail over would be a great start.
|
| Don't just say "it's hard." Of course it is. But is it
| cheaper to do this or to babysit rickety piles of junk?
|
| Another possible way out is AI sysadmins. I wonder how far we
| are from AIs that can admin a cluster including upgrades and
| disaster recovery?
| wly_cdgr wrote:
| Our software isn't horrible. Our software is pretty good,
| but reality is horribly unpredictable, complicated, and
| replete with edge cases.
| numpad0 wrote:
| I think AI should be used to cut down crufts. It just makes
| no sense to me that Linux Kernel boot images are, how much?
| A gigabyte?
| tredre3 wrote:
| > It just makes no sense to me that Linux Kernel boot
| images are, how much? A gigabyte?
|
| I guess the reason it doesn't make sense is that you're
| living in your own imagination where nothing is obligated
| to be sensical!
|
| The current boot image (vmlinuz) on my debian system is
| 6MB and the initrd is 40MB.
| genewitch wrote:
| no.
|
| > 11M Apr 6 12:14 vmlinuz-6.1.19-gentoo
|
| > 4.6M Apr 6 12:14 System.map-6.1.19-gentoo
|
| And that's a full desktop QEMU "server" - and i don't use
| initrd, because i don't need every driver in the tree,
| just the ones that work for my system. No AI needed. You
| boot a "kitchen sink" kernel, lspci -k, note down what it
| says, then just enable those things in the kernel and
| build it.
|
| Even ubuntu being "quite supportive" is 30-45MB.
|
| The kernel _source tree_ is over a gigabyte, but that has
| to support everything it supports - arm, risc-v, x86_64,
| etc.
|
| > 2.2G linux-6.1.19-gentoo/
| [deleted]
| hattmall wrote:
| I can't imagine having to unfuck the complicated systems
| set up by an AI sysadmin when the system running the AI
| goes down.
| arcanemachiner wrote:
| Understanding how a system works is so 2022. Just let the
| AI dig you in deeper.
| [deleted]
| askiiart wrote:
| And don't forget, the issue is always DNS.
| genewitch wrote:
| Did Not Service
| devjab wrote:
| > The amount of time we spent waiting for him to figure out
| why the server was misbehaving each week easily cost several
| times more than any hypothetical savings.
|
| I'm not going to argue with your points, but we've spent
| maybe a months worth of man hours figuring out why some SaaS
| service wasn't working this year. Only for it to be because
| some Azure or Office365 or Sharepoint online service wasn't
| healthy, and, to be fair, because some of our systems aren't
| build very maintainable so that it takes a ridiculous amount
| of time to figure out what is wrong. Still, it would've
| probably cost us maybe a work-weeks worth of time if we were
| more competent, which sort of goes against the SaaS idea when
| the licensing is also approaching the cost of self-hosting
| and hiring a Sharepoint person. Well, if a Sharepoint person
| existed of course, but I bet you get my point.
| dylan604 wrote:
| >Management liked it because it "saved a lot of money"... as
| long as you ignore the cost of the time we lost to dealing
| with it.
|
| bean counters tend to not evaluate your time as lost money.
| they are paying you anyways, so sunk cost fallacy or
| something. as long as they are not having to pay an invoice,
| they are "saving" money
| uoaei wrote:
| It's the converse of Goodhart's law -- if it's not
| measured/itemized, it's not part of the objective function
| for optimizing (costs).
| EddieEngineers wrote:
| Absolutely. The number of times I've pointed out a paid
| tool for $10pm is cheaper than a days salary per month to
| build in-house and maintain...
| Eduard wrote:
| Within the runtime environment spectrum's opposing ends
| _self-hosted_ and _SaaS_ , there exist several more choices,
| of which I consider _dedicated servers at some hoster_ the
| sweet spot for most projects /businesses, big and small.
| tornato7 wrote:
| I have recently ventured into home-hosting some non-critical
| services and it's awesome. I can get 5Gbps residential
| internet and a dedicated IP through AT&T fiber, I have
| Solar+PowerWall for uninterrupted power... Once I got through
| the first few weeks of Network manager and router problems,
| I've had zero downtime the past 6 months. Since our workloads
| are very SSD and bandwidth-heavy, both of which are absurdly
| expensive on public clouds, we hit breakeven to our cloud
| services in less than two months.
| explorer83 wrote:
| It's liberating to know that my emails can't be wholesale
| data mined or someone can't take down my web project if I
| commit some ToS thought crime. But doing it for clients was a
| ball-and-chain that I have no desire to do again. So for
| personal stuff it's great. For business stuff it's like
| adopting a pet that you can't leave alone too long. I would
| keep business stuff outsourced.
| throwaway834zz wrote:
| I leave my MacBook pro plugged in most of the time. Should I be
| concerned?
| frowin wrote:
| I think not. It keeps battery cycles low and is likely better
| than some other behavior. As far as I remember, batteries don't
| like to go way below 20% and don't like fast charging from 80%
| upwards. However, to my knowledge, it is wise to drain the
| battery 1-2 times a year so that the charging controller can
| calibrate. A way to do that is to type "yes" in your terminal
| (or 3-4 terminals) and wait, it will make the CPU run at 100%.
| After your MacBook shut off, leave it for some hours before you
| charge it again.
| Mizoguchi wrote:
| I had a barely used first generation iPhone in my safe and went
| to get it the other day to show it to some friends just to
| discovered it had blown up. It didn't look charred as your modem
| but it definitely exploded. Next day I ordered a few fire
| retardant boxes where I put all of my lithium batteries and power
| banks.
| jacquesm wrote:
| The problem is that there is plenty of stuff that you probably
| don't even realize has a Lithium Ion battery in it. With a
| phone at least it's obvious. But what about that controller for
| your e-bike? Camera? Remote control? Headphones? Authentication
| token? Toy? Microscope? and so on... they're _everywhere_. And
| they are not always announced properly, especially smaller
| pouch cells.
| jhdias wrote:
| https://www.phonak.com/en-us/hearing-devices/hearing-
| aids/ly... I find this egregious: "Lyric requires no
| maintenance or batteries to change or charge." and again "No
| batteries or charging needed."
|
| But you have two tiny potential bombs inserted into your
| head.
| capableweb wrote:
| > Better yet, Lyric requires no maintenance or batteries to
| change or charge.
|
| > The battery is specifically designed to withstand the
| deep ear environment for months at a time
|
| Have Phonak/Lyric achieved the impossible building a
| battery that never runs out of power? How does that work?
| zerocrates wrote:
| Looks like rather than replacing or recharging the
| _battery_ , you have the entire thing removed and a new
| one placed.
| Dylan16807 wrote:
| If it doesn't get charged then I doubt it has a lithium ion
| battery. But i can't find any specific information.
| robertlagrant wrote:
| This is why I cringe a little when people say "you can buy li-ion
| batteries for this much, therefore scaling it up to do renewable
| energy storage is cheap enough to do right now."
| kachnuv_ocasek wrote:
| Utility-scale batteries are a little bit different from these
| units in cheap consumer electronics.
| jacquesm wrote:
| They're different in scale but the cells are pretty much
| identical. There are only so many manufacturers and so many
| form factors and just about all of them are used industrially
| as well as for consumer stuff.
|
| Where they differ is how the cells are organized, safety
| measures taken outside of the cells themselves and things
| like cooling, mechanical construction of the assembly and so
| on. And even big manufacturers get things wrong, notably:
| Bosch. They have a pannier mounted e-bike battery pack that
| has serious problems with water ingestion, boards frying and
| balancing wires catching fire.
| dangus wrote:
| Your proof that utility-scale batteries don't work is that
| some random e-bike battery pack has design flaws?
|
| Utility-scale battery packs are climate-managed and are in
| real actual use right now. O'ahu has sunsetted its coal
| power generation and added utility-scale batteries:
| https://insideevs.com/news/614726/tesla-megapacks-hawaii-
| arr...
| jacquesm wrote:
| > Your proof that utility-scale batteries don't work is
| that some random e-bike battery pack has design flaws?
|
| I have absolutely no idea how you got that from what I
| wrote.
| louwrentius wrote:
| Lithium iron phosphate is a safer but less energy dense
| chemistry that is even cheaper than li-ion and actually is used
| at scale.
| tau255 wrote:
| Seeing the carnage I thought that there were no fuses for devices
| powered from 12V lead acid battery and some few hundred amps went
| through device.
|
| But, this is not really a failure of solar power system, just
| failure of a Netgear device. It seems that it used it's battery
| as a high current source for when it needed more peak power for
| wireless transmission, thus the instability and failures when
| just plugged to USB charger. I don't think such constant drain
| and constant recharge was really healthy for the battery. I
| wonder if it was/is stated in manual that it was supposed to be
| used charged and unplugged and not really as full time usage
| device.
| louwrentius wrote:
| My solar powered blog [1] is on LiFePo4 in part for this reason:
| no risk of spontaneous combustion.
|
| [1]: https://louwrentius.com/my-solar-powered-blog-is-now-on-
| lith...
| dheera wrote:
| I have some old phones mounted on my walls in various locations
| as control panels for Home Assistant. However every now and then
| one of them gets hot and its battery starts bulging, and I have
| to toss it. It's a problem even though they are (old) flagship
| phones.
|
| I'm looking for some kind of tablet that is wall-mountable but
| doesn't contain a Lithium battery. Some other kind of safe
| battery (NiMH?) that can last through momentary brownouts and
| power cuts of a few minutes would be nice.
| spockz wrote:
| How are you powering the server running home assistant and all
| the smart devices during the brown out? Can you hook up the
| tablet to the same power source? Or if they are not powered,
| what do you expect to manage during the Brownout?
| Saris wrote:
| >I was actually aware this could happen and technically shouldn't
| have left the battery in the device while it was hooked up to
| power constantly
|
| This really isn't on them at all, a properly designed Li-ion
| system will be absolutely fine left plugged in 24/7. Netgear
| either doesn't understand how to design a safe battery powered
| device, or this was a rare case of a bad battery just going off
| regardless of how you treat it.
| samtho wrote:
| I'm not sure which SD card was chosen in the past, but I do
| recommend upgrading to an industrial one (and not just high
| endurance), and they are typically purchased through electronics
| components retailers/suppliers.
|
| One brand I use is ATP for my ruggedized systems[0]. Yes, they
| may be an order of magnitude more expensive than even a high
| endurance from SanDisk or Samsung, but I started using these in
| 2015 or 2016 and found they hold in harsh terrain, tolerate brown
| outs (these devices are solar powered and run off of super
| capacitors), and JustWorks(tm).
|
| [0]: https://www.digikey.com/en/products/detail/atp-
| electronics-i...
| brainbag wrote:
| I clicked that link expecting to see an outrageous price, but
| it appears to be $28 for a 256 GB highly reliable SD card. That
| doesn't seem right. Am I missing something?
| tssva wrote:
| Or just run it off a USB drive.
| frowin wrote:
| Or an SSD. Is easy and cheap these days.
| mastax wrote:
| For the price of a mifi and a pi you can get a cellular wifi
| router and run code directly on there. Either from "random string
| of characters" on Amazon or Mikrotik or Teltonika. Then you have
| something designed to run 24/7 and most of them will run off DC
| power.
|
| Of course the router isn't as nice of a software environment as a
| pi but that's part of the fun, no? If you want easy just use
| GitHub pages or square space or whatever.
| pengaru wrote:
| I've gone through more swollen LiPo pouch batteries at my CA
| desert property than I can count, fortunately none have caught
| fire.
|
| The cheap ZTE devices in particular seem especially bad at
| keeping the thermals within a safe range. Even with a 100% full
| battery they'll let the electrolyte boil if left plugged in for
| their charging logic to do as it wishes in a hot environment.
|
| What's so frustrating is practically every consumer electronics
| device seems to now have some form of LiPo pouch cells in them. I
| wish it were normal for manufacturers to offer chunkier variants
| using NiMH AA/AAA cells to consumers. Instead I've been resorting
| to "industrial" stuff having no battery at all like the Gl-Inet
| X300B [0] I eventually ended up with.
|
| For a while I used a hacked together pack of four NiMH AAs with a
| battery board stolen from the LiPo on a ZTE/AT&T hotspot that
| kept swelling its pack. The battery board kept the device happy
| enough to believe it had the proper LiPo connected. The now
| external AAs stayed charged more-or-less, and didn't care how hot
| the ambient temps got through summer. But it was a sprawling mess
| of wires, soldered AAs arranged like an 80s-era RC-12L saddle-
| pack, kept ~together with Duck tape.
|
| [0] https://www.gl-inet.com/products/gl-x300b/
| ed25519FUUU wrote:
| Does NiMH handle overcharging better than lithium ion? I can't
| really find cheap charge controller ICs for NiMH batteries.
| tleilaxu wrote:
| The pictures do indeed speak for themselves! Goodness me.
|
| What are the statistics on lithium-ion battery failures? Are they
| dangerous full stop, dangerous in certain scenarios (e.g. heat),
| or do we only hear about the failures when 99.9999... of the time
| they are fine as they are everywhere?
|
| Are all lithium-ion batteries created the same?
| kristopolous wrote:
| > Are all lithium-ion batteries created the same
|
| No
|
| They have different chemistries with different characteristics.
| Some are safer than others
|
| See here
| https://en.m.wikipedia.org/wiki/Comparison_of_commercial_bat...
|
| Beyond the actual chemistry there's regulators of various
| quality and strategies that can be found in many modern battery
| packs.
|
| I'm not a professional in battery manufacturing but I'm sure
| there's somebody around here who is that can give more details
| reisse wrote:
| Take a look at this guy's setup. He put consumer modem into a
| closed outdoor box under the sun without any ventilation or
| cooling whatsoever. Given there is enough sun to power the
| solar battery, I'd bet the temp inside the box is >70 degrees
| C.
|
| I am honestly amazed the whole setup lasted for so long.
| j45 wrote:
| With so many unused hotspots out there maybe it's a few
| tweaks away.
|
| Battery management aside, those portable 12v fridges are
| great at using a fan to heat or cool
| fbdab103 wrote:
| That is what you have to plan for when dealing with
| consumers. That someone will stick the device somewhere in
| the messy real world because it is easy. You have to engineer
| for people "holding it wrong" when failures can lead to loss
| of life.
| bob1029 wrote:
| I like to do a bit of napkin math when storing batteries. I
| don't care what the technology or marketing says.
|
| Think about it in terms of "A 33kWH battery roughly equals 1
| gallon of gasoline". This is the most paranoid possible way to
| look at it, but it does help to establish some perspective.
| Energy is energy and if you don't really think it through, you
| may wind up with much worse than LTE modem/router fires.
|
| Tesla power walls are an example of something I could never
| install in my home due to this simple math. I would not be able
| to sleep at night knowing there is a chance they could go up
| while bolted to my home. I've got one of those EcoFlow
| batteries (2kWH) for emergencies, but I keep it on a concrete
| slab (protected from weather) outside my home.
|
| Go look at how a datacenter does their batteries if you want to
| get a sense of this very same paranoia at scale. All the DC-
| scale UPS systems I've seen typically consist of gigantic, low
| voltage cells installed in a manner expressly designed to deal
| with the worst case.
|
| I think the density of the energy is what is most dangerous in
| my mind. A whole room full of lead acid batteries might not be
| very portable, but its a hell of a lot easier to inspect room-
| scale components, prove they are safe, and deal with
| emergencies before they turn into catastrophes.
| reisse wrote:
| > Think about it in terms of "A 33kWH battery roughly equals
| 1 gallon of gasoline". This is the most paranoid possible way
| to look at it, but it does help to establish some
| perspective.
|
| Nah, that's the wrong way to think about it. Oxidation (well,
| burning) of lithium releases far more energy than the
| electric charge of the battery. Electric (dis)charge merely
| gives the initial heat to break structural integrity and set
| lithium on fire.
|
| And even then the problem is not in the amount of energy, but
| in that it's almost impossible to extinguish a lithium fire.
| And the fumes from battery are thick and toxic.
|
| > I think the density of the energy is what is most dangerous
| in my mind. A whole room full of lead acid batteries might
| not be very portable...
|
| Nah again. Lead-acid just does not burn so spectacularly. And
| about the energy density - filled fuel tank of a regular car
| has much higher energy density than Tesla battery, but is
| significantly harder to ignite, easier to extinguish, and
| when burning, releases the energy slower.
| George83728 wrote:
| The worst case scenario with a lead-acid battery is some
| manner of electrical fault leading to electrolysis in the
| batteries, releasing hydrogen and oxygen gas which
| subsequently may cause a very violent explosion.
|
| I've never heard of a house blowing up like this, but it
| has happened with submarines.
| Tool_of_Society wrote:
| Long ago a friend's car battery exploded. The car was an
| early 70s chevy nova so there wasn't much in the way of
| electrical system to check. Everything was good and the
| next battery lived +5 years with no changes.
|
| Always figured there was some minor defect or something
| that caused the battery to start emitting hydrogen.
| fbdab103 wrote:
| If I am ever in a scenario where I could have a house-sized
| battery system, I intend to have a disconnected concrete shed
| dedicated for storing them. Seems like a simple mitigation
| which would make me feel significantly better about the
| situation.
| bityard wrote:
| You might be interested in Lithium iron phosphate batteries
| which are MUCH safer than the traditional lithium ion
| batteries you're talking about here.
| fer wrote:
| > What are the statistics on lithium-ion battery failures? Are
| they dangerous full stop, dangerous in certain scenarios
|
| If you wanna get more paranoid:
| https://www.reddit.com/r/spicypillows/
|
| Jokes aside, hard to say, but it's mostly scenarios.
|
| Some batteries have proper venting (or puffing), protection
| circuits and sensors to prevent thermal runaway, and they are
| very unlikely to fail catastrophically, they would stop working
| before, generally.
|
| Now those take more space, so such features are often offloaded
| onto the PCB designers to make them fit, and you may trust them
| more (or less) than the battery manufacturer.
|
| More or less the same can be said about the charging circuit,
| and how it might handle low voltage or trickling/stop charge.
|
| Personally I've seen flashlights that burn through the 18650
| without respecting the minimum voltage whatsoever, and that
| would put 5V to charge. There a proper battery will refuse to
| charge or just die, but an unprotected one might catch fire.
|
| As anecdotal data, after dozens and dozens of devices, I've
| only owned two batteries that became spicy (without catching
| fire), a Chinese-brand laptop and a cheap quadcopter battery.
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