/diy/ - Do It Yourself

>>2522655
>if i can put any battery 18650

it'll work but it's not a good idea.
thats coz lipos self-discharge, so cant be left alone for a long time.
especially when it's hot, like in the summer in the trunk of a car.
they get weaker over time, and eventually die without a way to revive them.
so not good emergency use.
you're better off stocking a bunch of these instead, from a reputable vendor.