I want available backup power for my laptop (ASUS ux51vz, 19V/4.74A), I've got a pile of 10-20k mAh power banks, and I'd like a solution to marry the two somehow.
I know that I can get an external battery with a selectable DC output & appropriate power plugs (e.g. Anker Astro Pro2) for about $100, but that also only recharges from its wall plug instead of micro-usb like "regular" power banks (and so do all of its peers that I could find: poweradd, ravpower, qi-infinity, maxoak).
From a safety perspective, I suspect I'm better off getting a "laptop" power bank and using my regular power banks to charge that instead of directly charging the laptop (that way when I inevitable mess up, I only burn up a $100 battery instead of the slightly more valuable laptop).
It looks to me like one of these (DROK LTC1781 100W DC/DC Step Up Converter) will let me boost the 5V/1A or 5V/2A output of my power banks up to 19V, but is this a valid solution to the problem at all, and will it produce enough current to charge another battery? Should I connect two input batteries in series to get more current?
I would be open to commercial solutions, but it would be nice if I can do this with a minimum of new hardware.
Similar questions, all asking if a power bank can charge a laptop directly: