h a l f b a k e r y
OK, we're here. Now what?
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
or get an account
There's a lot of competing pressures on the design of
laptop computers. They should be thin, light, powerful
have good battery life. To get thin and light a small
battery helps, but the battery life will suffer, or a
compromise involving lower power components must be
around the conference table might look
with envy at the sleek object you are typing on, no-one
ever looks at the humble power brick. This allows a bit
design wiggle room.
Already I've seen quite a few adapters with USB ports for
charging, why not? it's already a switching power supply,
adding a 5V out is trivial. Since 5V is ideal for charging
Lithium cells, why not throw a nice rectangular Li-Po
into the design? 13mm extra thickness gets you a Li-Po
~8000mAh at 1s, or 44% extra charge on a Macbook Pro.
The cell should charge when the adapter is plugged into
the mains. When the mains is disconnected the cell can
supply the 18-20V to the laptop via a DC-DC step up
converter, a single ~90% efficient chip nowadays. In this
way the power brick acts as an external battery/power
This power brick can be used to partially de-couple the
location/time/mains status of computer charging. The
power brick can be left charging in your hotel room while
you have a super slim computer to take notes on, then
can pack everything away and your power brick can
your computer while you whisk yourself to the airport.
I'm aware that laptop power banks do exist, but these
more like UPS modules with inverters creating mains
Zero electricity air con
Add-on for LPBrick houses [Sgt Teacup, Jul 17 2019]
||This is a good idea!
For some computers (ie. the new one I recently bought...)
the power brick plugs in to a USB-C port anyway, so you
wouldn't need the 18V conversion. 5V out all the time,
whether using the brick as a mains connection or as a
Hmm... had a quick look at the specs; seems to output
EITHER 5V or 20V to the USB-C. The computer must talk to
the brick & ask for 20V to charge or 5V to run when fully
charged. Or something..?
||In the near future, there'll be African houses built of discarded Laptop Power Bricks, ingeniously re-configured to trickle charge from solar power, providing lights at night, fridge during the day. Presently, the top ends of 2-litre pop bottles arranged in rows on window inserts serve as passive aircon. Together, that's a classic off-grid house, except for the water/sewage. What other HB ideas can we re-purpose?!
||Obviously, bun for (b)unintentional building material. [+]
||//Hmm... had a quick look at the specs//
||yeah, USB-C is odd. You can pull 100W, there's even a USB-C
||The 2l bottle thing is not going to work in anything like the
way described. You can't cool air, or anything passively,
something else has to heat up, or volume changes, or
something changes state. The most effective feature of that
"device" is that it's acting as a window shade.
||There are also (apparently really good) soldering irons for
older kinds of USB, too. Only 10 watts or something but
everybody who's used one says it's great.
||Isn't the design goal to try and to get away from a tethered brick? To walk freely among the power supply patterns.
||One of the first laptops I used was a Compaq Armada. It had an internal power supply, so you just plugged a kettle lead straight into the back of it. If you needed more battery life, you could pull out the floppy drive and fit an extra battery into the bay.
||One of those (a Compaq laptop, at leastI'm guessing from your
description that it was an Armada, but I don't think I saw a model
name on it) showed up on the free shelf at Protospace and I tried
plugging it in. Finding a suitable thing to plug it in with was easier
than for most laptops, and the internal power supply seemed
quite novel. (It had a C6, taking a C5 cord, not the more common
C14 taking a C13 that I understand "kettle lead" to usually refer
to, though.) Unfortunately, the screen was broken, so I tried an
external monitor, but that didn't work for some reason. That was
several months ago, and I think it's still sitting on the table
nearby; maybe I should try to do something more with it, or at
least put it somewhere more suitable. The monthly clean is
tomorrow, so maybe I'll remember to do that then
||Years ago, well after the not just titanium but aluminium
PowerBook G4s were out, and after I had one, I still wanted a
PowerBook G3 with that same feature of being able to substitute
an extra battery for a drive. I think it was the Pismo I wanted, but
maybe it was the Lombard; I don't remember it very clearly now.
||When I get around to building laptops, expandable battery is a feature I
should remember to consider including.
||If capacity goes up, which it does, it is all down to form factor. Games can be played to stop upgrading(making a product better not dumping for new product).