This post grew out of a comment I made on Reddit in response to someone
who was frustrated with the Kindle walled garden and wanted more
generally-usable books.
I like to read. I have no idea how many books I’ve read in my lifetime,
but I own hundreds and hundreds of physical books, at least half of which
I’ve read; my digital library has around nine hundred books, most of which
I have yet to read; and I’ve read many more books besides the ones I own.
(When I was a teenager I’d walk out of the public library with a literal
armful of books, read them, then return two weeks later to do the same
thing all over again.) These days I prefer to read ebooks. It’s easier
to manage my ebook library and I can carry a lot more books around with me
in ebook form as compared to physical form. (No more armfuls of physical
books.) It really helps that I have a tablet
that doubles as an excellent ebook reader.
But I also prefer to actually own the things I’ve nominally purchased.
Many ebooks, including everything in Amazon’s Kindle ecosystem, come with
digital rights management, or DRM. DRM gives a book’s publisher control
over how you use your copies of their books. It’s theoretically intended
to impede piracy, but (a) it’s not too hard to bypass if you’re actually
intent on pirating the material, and (b) it effectively means that you
don’t fully own things you’ve purchased unless you go out of your way to
bypass it. It has enabled things like Amazon removing a copy of
Nineteen Eighty-Four
from a high school student’s Kindle library.
As a matter of principle, I will not pay for DRM-encumbered digital
media. If I buy something, I want to feel I actually own it, which
means I don’t have to rely on someone else mediating my use of the
media. So here’s where I get my DRM-free ebooks.
When I want to buy a particular book, my first stop is
eBooks.com. They have a good selection
of books, and they clearly indicate whether a given book has DRM or not.
Many book publishers or imprints have their own book stores, and some of
those offer DRM-free copies of their books. Some of the ones I know of are:
InformIT for several of Pearson’s
imprints, including Addison-Wesley. InformIT ebooks are DRM-free, but
are digitally watermarked to connect them to your account.
No Starch Press has books on programming,
computers, and other “geek entertainment”. They’ve got a very
good line of books for getting kids into programming.
I don’t have a problem with digital watermarks like the ones InformIT
uses. They don’t prevent any personal use of the watermarked
ebook; all they do is allow the publisher to take a copy shared online and
track it back to the person who originally bought it. For the most
part, digital watermarking doesn’t restrict use of the book any more than
copyright law restricts use of a physical book.
In addition to their ebook store linked above, Baen also has the Baen
Free Library, which
has a periodically-rotating selection of their books completely for free
(and also without DRM).
Tor Books, another science fiction/fantasy publisher, doesn’t have its own
storefront (it sells through ebooks.com, among others, and appears to
generally do DRM-free books), but it does have an Ebook of the Month
Club. To join the club, you simply sign up
for their newsletter. Every month you’ll get a link to download a free,
DRM-free book from their catalog. [The Ebook of the Month Club may
have been discontinued. The preceding link now redirects to the main
website, and it’s been a while since one of their newsletters mentioned a
free book.]
A good resource for out-of-copyright books is Standard
Ebooks. It’s a volunteer-run organization
dedicated to turning existing books into high-quality ebooks. Because of
the nature of their operation, they mostly focus on books that are no
longer restricted by copyrights. Their books are all well-typeset, with a
uniform appearance and consistent, well-curated metadata. (If you’re so
inclined, you can also contribute your own time and
talents to their efforts.)
Standard Ebooks largely stands as as an alternative to Project
Gutenberg. Project Gutenberg also has
ebook versions of many out-of-copyright books, but Project Gutenberg
focuses more on quantity than quality. (Also, they’ve been around a lot
longer; Project Gutenberg will celebrate its 50th anniversary later this
year.) In general, if a book is available from both Standard Ebooks and
Project Gutenberg, get it from Standard Ebooks. But if Standard Ebooks
doesn’t have it and Project Gutenberg does, Project Gutenberg’s copy will
be serviceable, even if it’s not necessarily formatted prettily and has
occasional typos from the automated optical character recognition.
I also follow Humble Bundle. They
periodically offer ebook bundles which are typically DRM-free and
available in EPUB, PDF, and MOBI formats. (Their quality has been
gradually declining over time, unfortunately. For example, some recent
book bundles have not had all of the formats for every book.) Not all of
Humble’s partners have good books (looking at you, Packt), and I’m not
always interested in the style, genre, or even just the particular
selection of books in a bundle. But I have gotten some good books out of
the bundles over the years, so I keep following them.
I have, over time, received recommendations from other people for
additional sources of DRM-free ebooks. Anything in this section is from
those recommendations. I haven’t used these sources extensively, if at
all, so take these with however many grains of salt you need.
The FreeEBOOKS subreddit is more
focused on ebooks that don’t cost anything, as opposed to ebooks without
DRM, and they don’t restrict themselves by ereader compatibility.
Nevertheless, many of the free books they link to are available as
DRM-free EPUBs.
Verso Books is an independent publisher
primarily focused on politically left-oriented content. Books are
DRM-free but watermarked.
Smashwords is an ebook store that focuses
on self-published authors. Their official position on DRM is that they
think it’s a bad idea but the decision of whether to use it is up to
books’ authors and publishers, not them. But, as of 2023, none of their
books have DRM and they say if they add DRM-encumbered books at some
point, such books would be clearly labeled as such.
Leanpub is a combination storefront and publisher.
They don’t use DRM on any of the books they publish and sell.
My preference for ebooks is for the EPUB format. It’s an open standard,
has broad compatibility, and is adaptable to a variety of readers and
environments. But there are some sources for books that use other
formats, most often PDF. PDF isn’t great as an ebook format because it
presupposes a page size and that page size is quite often either A4 or US
letter paper. Most ereaders have smaller screens than that, which means
the text is either small and annoying to read or you have to zoom in and
pan around to read everything. But sometimes a PDF is the best option for
a particular book.
The Internet Archive Text Archive has
scans of millions of books. Everything they’ve scanned is available in a
web browser where you can page through the scanned images. If the book is
still covered by copyright, you have to create an account and check the
book out in order to read it. Checkouts last for an hour and they can be
renewed. This whole system is pretty convenient in my experience,
especially for doing research, when you don’t necessarily need a book for
longer than it takes to look up and read a section, take any needed notes,
and check the section’s cross-references.
Some Internet Archive books are also available in EPUB, PDF, and other
formats. In those cases, you can download the file and do whatever you
like with them.
An alternate entry point to the Internet Archive Text Archive is the
Internet Archive Open Library. It facilitates
finding books in all sorts of libraries, but the Internet Archive Text
Archive is one of the sources checked. The site tends to be better for
finding either physical or browser-readable books, rather than
ereader-compatible books, though.
Wikibooks uses a wiki as a platform for
collaborative authoring of books. Most if not all of the book on
Wikibooks are nonfiction reference material. If you read the books on
their website, you’ll always get the most up-to-date text, but many books
can be downloaded in PDF format. A handful are also available in EPUB.
O’Reilly, a publisher of high-quality computer-related and technical
books, used to sell DRM-free copies of their books. If you’ve previously
bought any of those, you can still access them through
members.oreilly.com, but you can’t buy new
copies, as far as I can tell. O’Reilly seems to be moving instead to
subscription-based access to their ebooks, while still selling the
physical versions. They still have O’Reilly Open
Books, which links to all of the books
they’ve published under open licenses of various sorts, but very few of
them are available in EPUBs. Most of the open book links go to webpage
versions of the books, which aren’t as easy to get into an ebook reader
as a premade EPUB is.
The Emisar D4S flashlights use a firmware named RampingIOS V3. (The
Emisar D4, D1, and D1S all use RampingIOS V2.) There’s
not really a manual; the only thing we get is the diagram on the right.
It’s reasonably comprehensive, but there’s a fair amount of detail it
merely summarizes, so I thought a textual manual would be nice.
The Emisar D4S only works when the head and tailcap are tightened fully.
You can physically lock it out—prevent it from turning on
accidentally—by simply loosening the tailcap a small amount. A quarter
turn will do it.
Emisar lights are known for their ramping interfaces. Rather than have a
small number of distinct brightness levels, they can vary their brightness
anywhere between their lowest and highest levels, like a light on a
dimmer. The D4S is in ramping mode by default, but it also has a stepped
mode that can be configured to be closer to how non-ramping lights work.
Each mode—ramping and stepped—can have differently-configured brightness
floors and ceilings.
The driver for the D4S has two different chipsets. At low brightness
levels, a fairly-efficient but low-power chipset (called a 7135) is
used. These lowest brightness levels are called the “regulated levels”.
Each regulated level will always be the same brightness regardless of how
much charge the battery has. Above a particular brightness level, the
light switches over to a less-efficient but high-power chipset (called a
FET). These levels are called “direct-drive”. The brightness of the
direct-drive levels is directly related to the battery’s charge level; the
more charged the battery, the brighter the levels. The light is at its
most efficient, in terms of power used for every lumen generated, at the
brightest regulated level. When the light is first powered by tightening
the tailcap, it will default to this level.
At higher brightness levels, the light’s LEDs generate a lot of heat. If
the light exceeds its configured maximum temperature, it will begin
dimming itself automatically until the temperature drops below the allowed
maximum.
The D4S has a set of cyan-colored auxiliary LEDs that can be on when the
main LEDs are off. You can configure the behavior of the aux LEDs.
The default mode for the light is ramping mode. Triple-pressing the
button (3 clicks) while the light is on will toggle between ramping
and stepped mode.
While the light is off, press and release the button (1 click) to turn
it on. It will turn on at the last-used brightness level. (This is
called “mode memory”.) Immediately after loosening and tightening the
tailcap (or after changing the battery), the memorized level will be the
light’s max regulated level.
When the light is on, 1 click will turn it off. The current brightness
level will be memorized for future use. There’s a fraction of a second
delay between pressing the button and the light actually turning off.
That’s because of the way the light processes input; it’s waiting to make
sure you’re only going to press the button once (since multiple presses
will trigger other actions).
When the light is on, holding the button down will brighten the light. In
ramping mode, the brightness will increase gradually ("ramping up"). In
stepped mode, the light will jump through increasing brightness levels.
If you press, release, and then hold the button, it will begin dimming.
In ramping mode, the brightness will decrease gradually ("ramping
down"). In stepped mode, the light will jump through decreasing
brightness levels. While the light is changing, if you release the button
and immediately hold it again, the direction (dimming or brightening) will
switch.
In ramping mode, while the light is ramping, it’ll briefly blink off and
on again at two different brightness levels: the maximum regulated level
and the brightness ceiling.
While the light is off, double-pressing the button (2 clicks) will
immediately jump to the brightness ceiling.
While the light is on, 2 clicks will jump to the maximum brightness
level, regardless of the configured brightness ceiling. Another two
clicks will go back to the previous brightness level.
While the light is off, if you hold the button the light will turn on at
its lowest level. If you continue holding the button, the light will
begin brightening from there.
The light has several different configuration modes. Each of those modes
works more or less the same way. The mode will have a series of menu
items that it will go through. For each menu item, the light will first
blink a number of times corresponding to the item number (first, second,
etc.) After that, the light will begin fluttering on and off fairly
quickly. While the light is fluttering, you can click the button a number
of times; the light will count the number of button presses and use that
number as its new configuration for that menu item. After a short period
of time, the fluttering will stop and the light will move on to the next
menu item. After the light has gone through all of the menu items, it
will return to whatever mode it was in before entering the configuration
mode.
If you don’t press the button during a particular menu item’s fluttering,
that item will remain unchanged.
While the light is on, 4 clicks will enter ramping or stepped
configuration mode, depending on which mode the light was in before the 4
clicks.
For ramping mode, there are two menu options:
Brightness floor (default 1/150)
Brightness ceiling (default 150/150)
During the floor configuration, press the button equal to the number of
ramping levels (out of 150) at which the floor should be. To set the
lowest possible floor, click the button once.
The ceiling is configured similarly, but you press the button equal to the
number of steps away from maximum brightness. To set the highest possible
ceiling (at max brightness), click the button once.
The other modes largely involve multiple clicks from off. Most of them
are not generally needed for everyday use, but they supplement the light’s
basic operations.
From off, 3 clicks will enter “BattCheck” mode, which blinks out the
current battery voltage. First it blinks the number of volts, then it
pauses, then it blinks out the tenths of volts. Thus, if the battery were
at 3.5 volts, the light would blink three times, pause, then five times.
For zeroes, it gives a very short blink.
A fully-charged lithium-ion battery is 4.2 volts. The light considers 2.8
volts to be an empty battery and won’t turn on if the battery is at or
below 2.8 volts.
The voltage sequence will continue blinking until you turn off the light
with a single click.
While the light is in BattCheck mode, 2 clicks will enter TempCheck
mode. Instead of blinking out the battery voltage, the light will start
blinking out its current temperature in degrees Celsius, first the tens
digit then the units digit. Like BattCheck mode, the light will continue
blinking out the temperature until you turn it off with a single click.
While the light is in TempCheck mode, 4 clicks will enter thermal
configuration mode. See the thermal configuration mode documentation
below for how that works.
From off, 4 clicks will enter “tactical” or “momentary” mode. The
light will flash once to show that it’s entered the mode. The auxiliary
LEDs will turn off (if they were on). In tactical mode, the light will
turn on at its memorized brightness for as long as the button is being
held down. It will turn off as soon as the button is released.
There’s no button press combination that will exit tactical mode. To exit
it, you will have to partially unscrew and retighten the tailcap.
From off, 6 clicks will enter lockout mode. The light will flash
twice to show that it’s entered the mode. There’s a separate aux LED mode
for lockout mode, so you can tell whether the light is in lockout or not.
In lockout mode, pressing the button will turn on the light at its lowest
brightness ("moonlight mode") for as long as the button is held down.
Another 6 clicks will exit lockout mode. The light will flash twice to
show that it’s left the mode.
While in lockout mode, 3 clicks will cycle through the various
settings for the aux LEDs in lockout mode. The four modes are, in order:
low, high, blink (on high), and off. The default mode is blink.
Remember that loosening the tailcap a quarter turn will also lock out the
light. Using the 6 clicks is called “electronic lockout”, while turning
the tailcap is “physical lockout”.
From off, 8 clicks will enter beacon mode. In beacon mode, the light
will blink on and off every few seconds.
By default, the light will blink every two seconds. To change the timing,
use 4 clicks while in beacon mode. The light will enter a one-item
menu. During the flickering for input, press the button a number of times
equal to the number of seconds between blinks.
From off, 10 clicks will enter thermal configuration mode.
The menu items here are:
Current temperature (every click is one degree Celsius)
Temperature ceiling (every click is one degree above 30°C)
The “current temperature” item can be used to adjust the calibration of
the light’s temperature sensor. To use it, make sure the light has been
off long enough that all of its components have cooled (or warmed) to the
ambient temperature. Check the ambient temperature using a thermometer
you trust. Go to thermal configuration mode, and enter the current
temperature by clicking the button a number of times equal to the
temperature in degrees Celsius. (If it’s 22°C, click the button 22
times.)
You can check the default calibration by entering TempCheck mode from a
room-temperature light. The D4Ss are supposed to go through a temperature
calibration at the factory, so hopefully most of them won’t need manual
thermal calibration.
The temperature ceiling is simply the highest temperature the light should
be allowed to reach. Once it hits its temperature ceiling, it will
progressively dim itself until the temperature stabilizes below the
ceiling. Note that the number of clicks in that menu option is added to
30 to reach the actual ceiling. (Thus, you can’t set a ceiling below
31°C.) The maximum allowed ceiling is 70°C.
The Emisar D4, D1, and D1S flashlights all use a firmware named
RampingIOS V2. (The earliest D4s were released with V1, but there aren’t
many of those around. The Emisar D4S uses RampingIOS
V3.) There’s not really a manual; the only thing we get
is the diagram on the right. It’s pretty comprehensive, but I thought a
textual manual would be nice, so I decided to write one.
The Emisar lights only work when the head and tailcap are tightened fully.
You can physically lock out the lights—prevent them from turning on
accidentally—by simply loosening the tailcap a small amount. A quarter
turn will do it.
The lights use a ramping interface. Rather than have a small number of
distinct brightness levels, they can vary their brightness anywhere
between their lowest and highest levels, like a light on a dimmer.
The drivers for the lights have two different chipsets. At low brightness
levels, a fairly-efficient but low-power chipset (called a 7135) is
used. These lowest brightness levels are called the “regulated levels”.
Each regulated level will always be the same brightness regardless of how
much charge the battery has. Above a particular brightness level, the
light switches over to a less-efficient but high-power chipset (called a
FET). These levels are called “direct-drive”. The brightness of the
direct-drive levels is directly related to the battery’s charge level; the
more charged the battery, the brighter the levels. The lights are at
their most efficient, in terms of power used for every lumen generated, at
the brightest regulated level. When the light is first powered by
tightening the tailcap, it will default to this level.
At higher brightness levels, the lights’ LEDs generate a lot of heat. If
a light exceeds its configured maximum temperature, it will begin dimming
itself automatically until the temperature drops below the allowed
maximum.
While the light is off, press and release the button (1 click) to turn
it on. It will turn on at the last-used brightness level. (This is
called “mode memory”.) Immediately after loosening and tightening the
tailcap (or after changing the battery), the default level will be the
light’s max regulated level.
When the light is on, 1 click will turn it off. The current brightness
level will be memorized for future use.
When the light is on, holding the button down with gradually brighten the
light ("ramping up"). If you release the button and immediately hold it
again, the ramping direction will switch, so if it had been ramping up
it’ll be dimming ("ramping down") afterward.
While the light is ramping, it’ll briefly blink off and on again at three
different brightness levels: the minimum brightness, the maximum
brightness, and the maximum regulated level.
While the light is either on or off, double-pressing the button (2
clicks) will immediately jump to the maximum brightness level. Another
two clicks will go back to the previous brightness level. If the light
was off before the the initial two clicks, the second two clicks will go
to the memorized brightness level.
While the light is off, if you hold the button the light will turn on at
its lowest level. If you continue holding the button, the light will
begin ramping up.
The other modes largely involve multiple clicks from off. They’re not
generally needed for everyday use, but they supplement the light’s basic
operations.
From off, 3 clicks will enter “BattCheck” mode, which gives the
battery level. It blinks out the current battery voltage. First it
blinks the number of volts, then it pauses, then it blinks out the tenths
of volts. Thus, if the battery were at 3.5 volts, the light would blink
three times, pause, then five times. For zeroes, it gives a very short
blink.
A fully-charged lithium-ion battery is 4.2 volts. The light considers 2.8
volts to be an empty battery and won’t turn on if the battery is at or
below 2.8 volts.
The voltage sequence will continue blinking until you turn off the light
with a single click.
While the light is in BattCheck mode, 2 clicks will enter TempCheck
mode. Instead of blinking out the battery voltage, the light will start
blinking out its current temperature in degrees Celsius, first the tens
digit then the units digit. Like BattCheck mode, the light will continue
blinking out the temperature until you turn it off with a single click.
From off, 4 clicks will enter “tactical” or “momentary” mode. The
light will flash four times to show that it’s entered the mode. In
tactical mode, the light will turn on at maximum brightness for as long as
the button is being held down. It will turn off as soon as the button is
released.
Another 4 clicks will exit tactical mode. The light will flash twice to
show that it’s left the mode.
From off, 6 clicks will enter lockout mode. The light will flash four
times to show that it’s entered the mode. In lockout mode, the light will
not turn on, no matter how the button is pressed.
Another 6 clicks will exit lockout mode. The light will flash twice to
show that it’s left the mode.
Remember that loosening the tailcap a quarter turn will also lock out the
light. Using the 6 clicks is called “electronic lockout”, while turning
the tailcap is “physical lockout”.
From off, 10 or more clicks followed by holding down the button will
enter thermal configuration mode.
In thermal config mode, the light will first blink out the current maximum
temperature. As with TempCheck mode, it blinks the tens digit followed by
the units digit. If you release the button at this point, the light will
turn off and no changes to the configuration will be made.
If you continue to hold the button, the light will then flicker for a
second or so. After that, it will turn on at its maximum brightness. It
won’t turn off until you release the button, which you should do when you
feel like the light has gotten too hot. The temperature at that point
will be the new maximum temperature. The light will blink out that new
maximum temperature and then turn off.
I listen to a lot of podcasts, usually while I’m in the car, but also when
I’m doing yardwork and similar solitary tasks. These are the podcasts I
listen to.
I break my podcasts into several categories and generally listen to the
categories in order. (I listen to all of the news podcasts before
starting on the politics podcasts, and so on.) My currently-preferred
podcast client, BeyondPod, lets me set up a “smart playlist” that puts
everything in the appropriate order automatically every time I update my
feeds.
BeyondPod also lets me speed up podcasts. I listen to most of my podcasts
at 1.5x playback speed. I can still process the information comfortably,
but it gets through them faster. Exempted are more highly-produced
podcasts and ones that are really short anyway.
First, I listen to my “News” podcasts. These are short and, well, about
news. I listen to these in reverse chronological order, so I get the
newest news first.
The NPR News Now podcast is updated every hour and
contains a recording of the five-minute news summary they make available
to their member stations at the start of every hour. I have BeyondPod
update its feeds within an hour of my normal times for leaving home and
work, so I always start off my listening with an up-to-date news summary.
Schedule: Every hour, but you (obviously) only ever need the most
recent episode.
Up First is NPR’s podcast version of a morning show. It’s
hosted by the same people who host Morning Edition, and it’s available
every weekday morning. It spends about ten minutes discussing two to four
news topics in more depth than the hourly news summary can cover them.
Schedule: Every weekday, posted by 6am Eastern time.
WAMU Local News is just what it sounds like; short news items
from WAMU in DC. (WYPR is closer to me, but the reasons I instead listen
and donate to WAMU are a whole other post.)
Schedule: Somewhat ad-hoc; it depends on what reporting WAMU has done
on a given day. In general, there are three to five short episodes
every weekday.
The podcasts in this section are ones that cover topical issues, with a
focus on politics. I try to stay up to date on all of their episodes.
Sometimes I skip individual episodes in the interest of keeping up with
all of them.
I’m a bit on the fence about 1A, hosted by Joshua Johnson. I want a
podcast that covers a wide range of relevant topics, particularly politics
and cultural issues, and I want to come away from discussions with a sense
of understanding the perspectives on all sides of an issue, regardless of
whether I agree with them. The Diane Rehm Show used to be very good at
that; Diane assembeled good panels for discussion, and she was extremely
talented at guiding the discussion for the edification of her listeners.
1A took over Diane Rehm’s time slot and covers the same sorts of topics,
to a first approximation, so I’ve been listening to it since its
inception.
1A is different in a few ways, of course. The focus of the cultural
topics is a bit different, but I generally like the topics covered by the
show. I don’t think Joshua Johnson is as good a host, though. Diane was
good, in my opinion, at guiding her guests to present useful information
and perspectives to her listeners. Joshua has often come off as
condescending or offputting to his guests, in ways that I don’t think have
contributed to genuine, useful conversations. (In more than one show he’s
asked a guest a question that basically came off as him saying, “Do you
even understand why people think you’re wrong?”) I’m a little on the
fence about what they’ve done with the podcast format, too. The radio
show is two hours long, with a different topic each hour. For the
podcast, they pick one of the two topics and edit that show down to a half
hour. If you want to listen to the other show, you have to go to the
website; it’s not available in a podcast.
I still feel like I’m getting useful information and perspectives from the
show, but not to the same degree as I got from the show that previously
filled my “topical panel discussion” need. If anyone has suggestions for
better podcasts, I’m open to them.
Schedule: One 30-minute episode every weekday, distilled from the two
shows that aired that day. There’s often a bonus episode on the
weekend taken from one of the week’s episodes that didn’t get put into
its day’s podcast.
Playback: 1.5x, on general time principles, but Joshua also speaks a
little slowly and speeding him up helps.
On My Mind is the podcast that Diane Rehm has been doing since she
retired from hosting the on-air Diane Rehm Show. Every week she records
and collects conversations with people where she discusses political or
cultural topics. Her new format doesn’t really cover the sort of broad,
multifaceted discussions that I really liked about her old show, but she’s
still informative and insightful, so I’m still listening.
Schedule: Weekly. One hour-long episode every Friday.
Playback: 1.5x. Diane Rehm was the reason I started speeding up
podcasts in the first place. She’s an excellent host, but she talks
extremely slowly. (There are health reasons for some of that, but it
still makes it difficult to listen to her show sometimes.) Speeding
her up makes it a lot easier to get past the way she sounds and get
into the communication of ideas, where she excels.
The Economist has multiple podcasts; I listen to all of
them through their “all audio” feed, available at the top of that page. I
do skip their “Tasting Menu” episodes; I find the format they use for them
jarring. (It consists of one person reading excerpts from an article
they’ve written for the magazine intercut with the host’s commentary on
the article. It feels like a conversation format where the two people
aren’t actually talking to each other and I don’t like it.)
The Economist has the nice additional benefit of giving coverage of the US
from an outside perspective. I appreciate that because pretty much all of
the other podcasts I listen to are based on the US.
Schedule: There are currently five podcasts; each one is
published weekly on a different day of the week, so the all audio feed
gets a new episode every weekday.
The FiveThirtyEight Politics Podcast doesn’t have its own page, but you
can find it on the FiveThirtyEight Podcasts page. This
weekly podcast features concrete, numbers-based discussions about
political developments. I really like their approach to trying to
understand the population’s political opinions by asking them (generally
through polls) and trying to fairly listen to the answers.
Schedule: Weekly. Episodes are recorded around noon on Mondays and
posted that afternoon. Sometimes they do “emergency podcasts” on other
days to discuss particularly interesting political news developments.
On the Media is a weekly show that discusses how the US—and
sometimes global—media is covering (or miscovering or failing to cover)
the news, particularly political news. They also tend to discuss free
speech and various other things that fall within a similar penumbra
Schedule: Weekly plus. The hour-long radio show airs on Fridays, so
they post new shows to the podcast feed on Fridays, too. The podcast
also gets “podcast extras” every Wednesday.
Playback: 1x. Although it might not sound like it at first, the show
is very highly produced and edited. Each episode packs a lot more
content into each time period than most of the other podcasts I listen
to, so I leave this one at 1x playback.
These podcasts are excellent places to learn new things. They’re not
necessarily as time-sensitive as the ones in my “Politics / Topical”
section, so I get to these only when I’ve caught up on all the topical
stuff. I am currently about five months behind on this section.
99% Invisible discusses the design of things made by humans, with
a focus on architecture. I’ve learned a lot about all sorts of things
that people have made from this show.
Schedule: Weekly. One half-hour episode every Tuesday.
Playback: 1x. This show has high production values and it’s worth
listening at regular playback speed.
Radiolab tells stories about science. I’ve learned a lot from
this podcast about new developments in science, obscure but interesting
scientific discoveries, and science history. They also do a lot to try to
express concepts and atmosphere through audio cues. At least one person I
know finds their “bleeps and bloops” offputting and can’t listen to them.
Schedule: They don’t seem to have a hard and fast schedule these days.
They usually put out two to three episodes a month.
Playback: 1x. A lot of work goes into the show’s production, and it
doesn’t sound the same when sped up.
The TED Talks audio feed is just that: an audio-only podcast
of TED talks. I’m a little on the fence about this one. I’ve listened to
some really great talks through this feed, but a lot are just okay or
worse. The ratio is not really in the feed’s favor. I haven’t fully
given up on it yet, though.
Schedule: Every weekday. Most talks are 18 minutes or less.
Playback: 1x. A lot of the talks could probably be sped up without
issue, but the good ones usually have a rhythm and performace aspect to
them that is better appreciated at 1x, so that’s where I leave the
entire feed.
What’s the Pointwas a podcast from FiveThirtyEight that
discussed uses of data in various aspects of our world. One of the early
episodes I distinctly remember was a discussion of analyzing traffic data
in New York City to optimize traffic flows in Manhattan (including closing
a street to improve the traffic). The podcast has ended, but I haven’t
yet listened to all of the episodes in the feed.
Schedule: Ended. When it was active, it was weekly, with a new episode
every Friday.
If I ever get caught up on my “Education” category, I have the “Catching
Up” category to work on. When I find a podcast that I like and want to
listen to every episode of it, I put it in this category. Once I’m caught
up on the podcast, it gets moved into an appropriate other category
(usually “Education”). 99% Invisible, TED Talks, and Radiolab all started
out here.
Intelligence Squared US holds one or two debates every month on
interesting topics, often political ones. Each debate begins with a
motion, e.g. “Video games make us smarter.” There are two teams in the
debate; one argues for the motion and the other argues against. Each team
has two members. The debate has three phases: opening statements,
answering questions from the moderator and audience, and closing
statements. The audience is polled about their opinion on the statement
before and after the debate; the side that had the greatest increase in
supporters is said to have won the debate. I don’t care so much about who
wins or loses, but the debates are generally good platforms for
understanding opposing perspectives on contentious topics.
Schedule: One to two hour-long episodes every month.
Playback: 1x. I think the performace aspects of the debate are better
expressed at normal playback speed.
Questions about buying batteries come up periodically on the
/r/flashlight subreddit. This is the guide I wish had existed when I
had those questions. The primary focus of this guide is on batteries that
go into flashlights, though some of what’s here can certainly be applied
to other battery-powered devices.
If you just want to know how to get 18650 batteries, skip down to the
Lithium-Ion section. Be careful when buying
lithium-ion batteries from marketplaces like Amazon; unsafe batteries
abound. See the section for advice on making safe purchases.
Batteries can be separated into different types that largely have to do
with their voltage. A battery’s voltage is determined by the chemical
reactions it uses to generate electricity (and occasionally with
additional circuitry added to the battery). The usual way we refer to
batteries (AA, AAA, C, etc.) specifically references their size, not
voltage. Fortunately, for the most part, particular sizes only come in
particular voltages. I’ll note a few places you might have to take care.
Flashlight batteries generally fall into one of three categories (links go
to the sections on each type of battery):
1.5V - These include the most common battery
types in use, including AAA, AA, C, and D.
3V - The most common 3V flashlight battery
is the CR123A. Many button cells (watch batteries) are also 3V, like
the common CR2032.
Lithium-Ion - This is a whole class of
batteries that have higher outputs and last longer than many other
flashlight batteries, but they require more care in handling.
Lithium-ion flashlight batteries usually have five-digit designations,
like 18650 and 10440.
I’m omitting stuff like 9V batteries and 6V “lantern batteries”, since
they’re not used in flashlights to the same degree that the above
categories are.
Flashlights that use AAA, AA, C, and D cells are very common. They’re
useful because those cells are also very common.
People sometimes refer to these batteries as either “primaries” or, less
often, “secondaries”. “Primaries” are synonymous with non-rechargeable;
you use them and then throw them away. “Secondaries” are synonymous with
rechargeable, though people will more often just call them “rechargeable”.
The main consideration when choosing 1.5V batteries is the chemistry used
inside. There are three common chemistries:
Alkaline - The cheapest and most common. Not recommended unless
they’re your only option. They’re not rechargeable, so you have to
replace them every time you use them up. They lose their charge over
time, so if you leave them alone for a while, they might not even be
useful when you do pick them up. They tend to leak, which becomes more
likely the more they discharge (and remember, they lose charge even if
you’re not using them). When they leak, they can destroy whatever
device they’re in.
Nickel-metal Hydride (NiMH) - Rechargeable. People will often refer to
“Eneloops”, a specific, well-regarded brand of NiMH batteries. Good
for frequently-used flashlights because you can reuse them rather than
buying new ones all the time. They also don’t leak, so you don’t run
the risk of damaging your devices. Standard NiMH batteries lose charge
much faster than alkaline batteries, but you can get “low self
discharge” NiMH batteries that only lose their charge slightly faster
than alkalines do. (Rough comparison: after a year without use or
charging, an alkaline battery will have 80-90% of its original charge,
an LSD NiMH will have 70-80%, and a regular NiMH will have 15-20%.)
Although alkalines usually claim more energy storage than NiMH on
paper, NiMH batteries tend to give longer runtimes in flashlights in
practice because of the way modern flashlights use electricity.
Lithium - Expensive, but long-lasting. Not rechargeable. These
typically cost three times or more what alkalines do. (So do NiMH
batteries, but those are rechargeable, so the cost is amortized over
many reuses.) They lose their charge more slowly than alkalines, they
can store more energy than alkalines or NiMH, and they don’t leak.
Good for devices you want to leave alone for months or years at a time
and still work as soon as you pick them up again.
There are rechargeable alkaline and rechargeable lithium batteries, but
rechargeable NiMH are the most common at the moment. Nickel-cadmium (NiCd)
used to be the most common rechargeable chemistry, but it’s been replaced
by the NiMH, which is better than NiCd in practically every way.
In most cases, you should get NiMH rechargeable batteries for flashlights
that get used frequently. For flashlights that sit and wait to be used
(emergency flashlights, bug out bags, etc.), use lithium primaries.
Lithium batteries handle temperature extremes better than NiMH and
alkaline batteries, so lithium is also the best choice for things like
flashlights that live in cars.
3V batteries are common in a number of more niche devices, like cameras.
There are a lot of flashlights that use 3V CR123A batteries. Pretty much
every 3V battery uses lithium, so everything about lithium in the
1.5V section applies to 3V batteries, too.
The higher voltage lets some CR123A flashlights put out more light than
similarly-sized AA flashlights. Aside from that, there’s not much to
consider about buying CR123A batteries.
Some places sell “RCR123A” batteries, which are basically CR123A-sized
lithium-ion batteries. (Specifically, they’re 16340 cells; lithium-ion
naming conventions are covered below.) Some RCR123A batteries have
integrated voltage-regulating circuitry to deliver a constant 3V so they
behave just like a regular CR123A. Others do not; like other lithium-ion
batteries, they’ll be 4.2V when fully charged. If you’re going to buy
RCR123A batteries, either make sure your device can handle voltage up
to 4.2V or check the specs on the RCR123A to see whether it has a 3V
output. (Lithium-ion batteries will often be listed as having a 3.6V
output or so.)
All of the usage considerations in the lithium-ion
section apply to RCR123A batteries, too.
Lithium-ion batteries brought a revolution in compact energy storage.
They can hold more energy and discharge it faster than any of the common
handheld battery technologies that came before them. Lithium-ion
batteries are used, in some form, in devices ranging from smartphones to
laptops to electric cars.
Lithium-ion batteries supply 4.2V when fully charged. As their energy is
drained, their voltage drops. When they reach 2.5V or so, they’re
considered empty. Lithium-ion batteries are usually referenced by the
average voltage across their entire discharge range, which is usually 3.6V
or 3.7V.
Although a lithium-ion battery can continue to supply power below 2.5V,
doing so runs ths risk of permanently damaging the battery’s chemistry.
That might reduce the energy the battery can hold when full, render the
battery useless, or cause an internal short circuit that could lead to a
fire.
Lithium-ion batteries are also potentially more dangerous than the other
batteries described above. If they get too hot, they can catch fire or
explode. Charging and discharging lithium-ion batteries both generate
heat, so doing either one too fast can cause a fire or explosion. A short
circuit—connecting the positive and negative ends without enough
resistance in between—will almost certainly discharge the battery too
rapidly. (For people who remember the Samsung Galaxy Note 7 fires, those
were caused by unsafe lithium-ion batteries.)
The above doesn’t need to put you completely off lithium-ion batteries.
They’re incredibly useful; you just need to take a little more care with
them than other common batteries. Some lithium-ion batteries are more
safe than others; that’ll be covered below.
You do need to be careful about where you buy your lithium-ion batteries.
Many large marketplaces, like Amazon and AliExpress, have unsafe or
mislabeled lithium-ion batteries for sale. Because of the dangers of
unsafe usage of such batteries, you need to make sure you’re getting them
from a reputable seller. That will be covered in the buying lithium-ion
batteries section.
Some flashlights have built-in charging circuits. If yours doesn’t,
you’ll also need a charger, covered in the chargers section.
The Lithium-ion batteries that flashlights use—at least, flashlights with
removable batteries—are generally cylindrical and are described by a
five-digit identifier, like “18650”. The first two digits give the
diameter of the cylinder in millimeters (mm). The last three digits give
the length of the cylinder in tenths of a millimeter. Thus, an 18650 cell
is nominally 18mm by 65mm. There’s some variation in those values,
particularly in the length, but they give a rough approximation.
Some common sizes are:
18650 - The most ubiquitous size for lithium-ion flashlights, as well
as for a lot of other things (laptop batteries, smartphone power banks,
and so on). Because this is currently one of the most popular sizes in
industrial use, it’s gotten the most research into making it
efficient. As of January 2018, no other shape matches the energy
density of the 18650. (e.g. a 26650 has twice the volume of a 18650,
but the best 26650 only has 1.5 times the energy of the best 18650.)
26650 - The 18650’s larger sibling. Used by some flashlights to give
more runtime per battery.
21700 - A relatively newer size that some companies are starting to
use. It seems possible that 21700 might someday replace 18650 as the
most popular (and, thus, best-engineered) battery size. For now, there
are a few flashlights that make use of the larger capacities and
discharge currents that 21700 cells have in comparison to 18650 cells.
18350 - Almost half the size of an 18650. A number of flashlights have
options for swappable longer and shorter battery compartments, so you
can decide on a daily basis whether to have a shorter light that uses
18350s or a longer light (with longer runtimes) that uses 18650s.
16340 - More or less the same size as a CR123A. There are used in
“RCR123A” batteries as described in the 3V
section above.
14500 - More or less the same size as a AA battery. Some flashlights
can use either AA or 14500 cells. Don’t use a 14500 battery in a AA
light unless the flashlight manual says you can. If the flashlight
only expects 1.5V batteries, using a 4.2V 14500 can destroy the light
and possibly start a fire.
10440 - More or less the same size as a AAA battery. Some flashlights
can use either AAA or 10440 cells. Don’t use a 10440 battery in a AAA
light unless the flashlight manual says you can. If the flashlight
only expects 1.5V batteries, using a 4.2V 10440 can destroy the light
and possibly start a fire.
A number of flashlights allow you to use either an 18650 battery or two
CR123A batteries. As with 14500/AA and 10440/AAA, don’t do this unless
the flashlight manual says you can, since two CR123A batteries in series
will give the flashlight 6V.
When speaking, most people break up the five digits of a lithium-ion
battery into three groups: xx-y-zz. Thus, “18650” is pronounced
“eighteen-six-fifty”. (“14500” is usually pronounced
“fourteen-five-hundred”.)
With 1.5V batteries, you have just one thing to decide about: the battery
chemistry. With lithium-ion batteries, there are four options you need to
consider: protection, top shape, capacity, and discharge rate.
If in doubt, you’ll probably be okay with protected, button-top batteries
of the highest capacity you can afford (ignoring discharge rate).
Dimensions of plain, button-top, and protected 18650s.
As noted above, lithium-ion batteries should not be discharged below 2.5V
or so and should not be discharged too quickly. Many manufacturers take
plain lithium-ion cells and add small protection circuits to them. These
circuits stop providing power if the battery voltage drops too low or if
the current draw gets too high, protecting the cell from things that could
damage it. This makes the protected batteries a bit safer, since it’s
more difficult to accidentally push them too hard.
A protection circuit makes the battery a little longer, and sometimes a
little wider. There are flashlights that have so little extra space
inside that they must be used with unprotected batteries. Usually such
flashlights will have their own low-voltage protection (LVP) and will stop
trying to use the battery if the voltage gets too low. If you use an
unprotected battery in a flashlight without LVP, you’ll have to be careful
not to drain the battery too far or you risk permanently damaging the
battery.
Protected batteries usually cost a little bit more than their unprotected
counterparts, typically in the realm of an extra $1.50 or so.
Some high-powered flashlights need to draw so much current that they can’t
use protected batteries because they’d trip the protection with their
power usage. For those flashlights, make sure you get unprotected
batteries with a high enough discharge rate (covered later).
Flashlights that need unprotected batteries should say so on their website
and in their manual. If there’s nothing about protection, you should be
able to use protected batteries (and you ought to do so).
Tops and bottoms of flat top, button top, and protected 18650s.
Lithium-ion batteries, like all other batteries, have a positive end and a
negative end. Putting a lithium-ion battery in backwards can damage the
flashlight, the battery, or both. In some cases, it can start a fire.
On a plain cylindrical lithium-ion cell, the disk on the positive end is a
little smaller than the disk on the negative end. Some manufacturers take
bare cells and put buttons on top of them, like the buttons on top of 1.5V
batteries. This makes the battery a little longer, but not as much as a
protection circuit does. Most unprotected-batteries-only flashlights will
still work with button top batteries.
Button top batteries usually cost slightly more than flat top batteries.
The extra cost is generally somewhere around ten to twenty cents.
Many flashlights will work with either button top or flat top batteries.
Some are shaped so that only a correctly-inserted button top battery will
work. This serves as mechanical enforcement of correct battery polarity.
If your flashlight takes more than one battery in series, you’ll need to
use button-top batteries.
Protected batteries pretty much always come with button tops.
In general, any flashlight that works with flat tops will also work with
button tops, except for rare cases where the battery compartment spacing
is incredibly tight. Consequently, I’d recommend getting button top
batteries unless you specifically know you need flat tops.
A battery’s capacity, most commonly measured in milliamp-hours (mAh),
governs how long it can continue providing power. More mAh generally
equals more flashlight runtime. Even if you don’t expect to run a battery
all the way down, keep in mind that as a lithium-ion battery discharges
its voltage drops. In many flashlights, that means that a
partially-discharged battery can’t support the brightest modes on the
light. A higher-capacity battery will continue to provide higher voltages
for longer periods of time.
If all else is equal, you should get the highest-capacity battery you want
to spend money on.
Many disreputable battery vendors claim impossibly high capacities for
their batteries. As of January 2018, here are the highest manufacturered
capacities for some common lithium-ion sizes; if a battery claims
significantly higher numbers, it’s probably lying (and if it’s lying about
capacity, it’s a lot more likely to be lying about other things, like
safety):
16340 - 700mAh (see the note below about Efest)
18350 - 1200mAh
18650 - 3600mAh (but see the note below)
26650 - 5500mAh
(Note: Efest, a reasonably reputable brand, sells “850mAh” 16340s, but
testing indicates that they’re more than a little optimistic about that
claimed capacity. In practice, 700mAh is the most you’ll get out of
a 16340.)
(Note: Only one 18650 cell claims a 3600mAh capacity, and it’s arguably
cheating a little to get that number. For most practical purposes, you
can regard 3500mAh as the highest available 18650 capacity, and consider
any “3600mAh” battery to really be 3500mAh.)
Depending on their particular chemistry, lithium-ion batteries can have a
maximum discharge rate anywhere from 3 amps (A) to 40A. Most flashlights
stay under 3A-4A, so pretty much any battery will be fine for them. Some
of the higher-output flashlights need or can benefit from 10A, 15A, or
even 20A batteries.
There’s a tradeoff between battery capacity and discharge. The
chemistries that do very well on one metric are not as good on the other.
As of January 2018, the best high-capacity batteries store 3500mAh with a
maximum discharge of 10A, while the highest-discharge batteries can
sustain 40A but only store 2000mAh.
The most-demanding flashlights I’ve seen top out at about 20A, so you
probably don’t need to go out looking for batteries with higher discharge
rates than that. (Unless you’re also using the batteries in your vape or
something.) Many people with high-drain flashlights like to use Sony VTC6
or Samsung 30Q batteries; both are 3000mAh/15A.
Some people refer to high-discharge batteries as “IMR” batteries, after a
commonly-used chemistry for such batteries.
In general, you should see if your flashlight has a maximum current drain
listed. If it doesn’t, ignore discharge rate and get the highest capacity
batteries you want. Otherwise, get the highest-capacity batteries with a
high enough maximum discharge rate.
There are all sorts of other characteristics that people care about with
their batteries, but those are less relevant than the above four things,
especially if all you care about is getting your flashlight to work.
There’s actually a really complex relationship between batteries'
capacity, voltage, and current. Batteries are a little less efficient at
higher amperages, so a flashlight that’s constantly used on its turbo
setting will generally drain its battery even faster than the numerical
difference between the light’s brightness levels would indicate.
Similarly, batteries providing higher amperages will have their voltage
drop a bit relative to the same battery with the same charge but at a
lower current draw. Different batteries will have different balances
among those relationships (e.g. Samsung 30Qs exhibit slightly more voltage
sag than Sony VTC6s, even though their top-line ratings are the same).
These sorts of things only tend to matter to people who want to squeeze
every last lumen out of their lights, and those are just a small subset of
the people who use lithium-ion flashlights on a regular basis. If you’re
interested in this level of detail, though, you will want to look at
HKJ’s battery and charger reviews. The website is a little
confusing in its layout, but there’s a wealth of information about all of
the batteries HKJ has tested, and HKJ has tested a lot of batteries.
Don’t just go to Amazon, search for “18650”, and buy the first search
result. There are a lot of cheaply-made and more-unsafe-than-necessary
batteries in large marketplaces like Amazon. You should buy from a vendor
who will only sell properly-labeled stock from trusted manufacturers.
One of the easiest ways to do that, as well as to search for batteries
that match all of the options you need, is to use the
Parametrek Battery Database. The person who
maintains the database has links to purchase batteries from reputable
sellers. For a search example, here’s all of the protected 18650
batteries, with the highest-capacity ones first:
Note that to search for capacity, the mAh numbers I’ve talked about are on
the “mAh” category. The “capacity” section sorts by watt-hours (Wh)
instead. (The basic difference is that milliamp-hours are only directly
comparable for batteries at the same voltage, while watt-hours give
meaningful comparisons even between batteries with differing voltages.
Lithium-ion batteries are generally marketed with their mAh rating—since
the voltage is known—so that’s what this guide uses, too.)
If you have questions about a particular battery seller, you can always
come ask about it on the /r/flashlight subreddit.
Unprotected batteries are pretty much all made by LG, Panasonic,
Samsung, Sanyo, or Sony.
Some of the more popular brands for protected batteries include AW,
EVVA, and Keeppower.
(As mentioned previously, these companies buy
unprotected batteries from the above vendors, add their own protection
circuits, and sell the resulting batteries.)
Many flashlight manufacturers have their own branded batteries. Those are
generally of good quality, but they’re often more expensive than
equally-good batteries from other reputable sellers. Some people prefer
to pay the extra amount just to avoid trying to figure out whether a
particular other seller is reputable or not.
Batteries from Olight are a little unusual. They’re a reputable
manufacturer (and seller, if you buy directly from them), but they do some
extra things to their batteries. The tops of their batteries have a
positive button, like any button top battery, but also a negative ring
around the button. This is required for the batteries to work in their
proprietary flashlight charging cradles, but it increases the chances of
short-circuiting the batteries. (The protection circuit should prevent a
short-circuit from starting a fire, but it’s still not something you want
to do to a battery.) Unless you’re using an Olight flashlight with an
Olight charger, you probably don’t want an Olight battery.
Ultrafire batteries should be avoided. They’re known to cut corners
on their batteries in order to make them cheaper. If you buy one of their
batteries, you might get something that works, but you also might get a
battery with a defective protection circuit, or a battery that contains a
smaller, cheaper battery, and a lot of sand to fill the extra space.
Given the care that needs to be taken with lithium-ion batteries, the risk
isn’t worth the lower prices.
If you go with rechargable batteries, you’ll need a charger. (Some
lithium-ion flashlights have built-in charging, but even with those an
external charger can be useful sometimes.)
The best option is to look at the list of
chargers reviewed by HJK, pick one with the features you
need (number of bays, NiMH, lithium-ion, etc.) and a good rating (two or
more smiling faces), and buy it from one of the reputable battery vendors
discussed above.
