Was looking at making a DIY battery bank, but I've got a

please ask /diy/

>>58881156
You should go with a reputable brand like samshit or something like that, don't buy the cheap chinese ones advertising capacities like 5600 mAh and such, in practice they literally have only 1/10 of that. Anything above 4000 is definitely fake, anything above 3000 for cheap is likely fake. Also, what do you want to use it for? If you want to charge your phone with it, you need some powerful step-down circuit to make it 5V. Also you should get a real powerful charging circuit, otherwise it will literally take 10 hours to charge the battery bank, and it should have discharge and overcharge protection (battery bank should shut off if the batteries get below ~3.3V and charging should stop if the voltage goes above 4.2V).

>>58882415
Also, if you have a laptop, you should make it compatible with its charger by getting the right circuit, because charging that thing from USB is not an option.

>>58881156
>should I be using 18650s? is there a better battery that I can use?
21700 batteries are hitting the market soon and they're billed as the replacement nextgen to 18650.

>
I like the Sanyo-ish ones, equivalent to other mid-range like NCR, and cheaper
>
Could go 26650s

Hope you're not making a 5V bank, since kits and boards are everywhere.

>>58882456
uh yeah you can step up voltage you dipshit

>>58884157
The USB standard limits the max amps you can put through USB cables to something abysmal you dumbass, so good luck finding an USB power supply that can output the ~50 watts you'd need to charge this thing in a reasonable amount of time. And even if you did find one and somehow made the thick-as-fuck USB cables that could handle 10 amps, the USB ports would still melt or catch on fire.

>>58884157
Put the cells in pairs and you get nominal 7.4V which you can step down to 5V.
Power limit is defined by resistors to the data pins or by a USB power profile.

Never knew /g/ was that stupid.