Recharge laptops tablets phones on a 12 V battery

[leftbrainstuff]

Originally Posted by hellosailor

"Most laptops need 19v DC to charge."
And try as I may, I can't ever get an answer as to why that is. Some of the Toshiba's used to use just 12 volts, years ago.
But there's nothing IN a laptop that runs on more than five volts, except of course the battery pack, and that's often only around ~10 volts anyhow.
If anyone has heard "the 19v rationale" from anyone who actually knows it, please do share.

Nearly all laptops require more than 12V on the supply side just because they always have.

Your options are:

1) wait till USB C becomes the new standard. Dont hold your breath
2) purchase a 12V transformer. Some laptop OEMs offer an option. Most have insufficient wattage and dont offer clean power.
3) Run an inverter from your house batteries to supply AC.
4) purchase a good quality fan equipped 300W inverter which connects to 12V

We have only 2 persistent AC loads now. The tv and laptops. When on the hook we use two 300W portable inverters instead of our main 2000W inverter.

We have a 2000W and a spare 2500W inverter on our 675Ah house bank which we hardly use. We only use AC for ironing, running the bar mix and running non cordless power tools.

DC to AC inverters have losses and so too does DC to DC conversion. We run a startup and associated NAS, modems, hardware firewalls, etc all direct from 12V. It's clean, smooth reliable power with no parasitic conversion losses.

Make sure your cig lighter 12V connections are good quality and wired to a bus bar with the appropriate gauge wiring. Don't use cheap, crap automotive aftermarket cig lighters. They are junk and aren't rated for continuous power draw.


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[hellosailor]

Sooner-
Wire gauge.....Not really an issue. I was inside a 50W LED floodlight looking for a loose connection yesterday, and the wiring to the LED itself was carrying over 10 amps, and still looked like "doorbell" wire. Without running the numbers, this is a non-issue, can't see that as being an engineering priority.


socald-
I use Powerpoles for many things, but for the casual user I can't recommend them. Simply because they are a flaming █itch to crimp properly, unless you buy and shelter one of the dedicated crimpers, another $50? one-trick pony.

left-
USB-C is actually deploying now. Too slowly, but deploying. And I'll bet the laptop supplies still don't change, even if the tablets do.(G)