hello @f1v3 and welcome to the Purism forums !
you can replace the battery only with tools (you need a cross screwdriver to detach the back and take the battery out after you carefully “detach” it from the power-line.
the phone must be in a poweroff mode while you atempt this. you also need to be stationary in order to not lose the screws when you take them out.
hot-swapable means you just pop-out the battery after you SLIDE the back-cover out. it doesn’t require ANY tools just your hands and a second charged battery of the same type.
if you aren’t too bothered by the not-hot-swapable nature of the L5 battery you can also use what i call a middle-ground solution.
bare with me please. i will atempt to explain.
first > Librem 5 battery spec : built in or replaceable?
second > Feature request: hardware switch for system power - #4 by blendergeek
third > Question about long term battery life - #6 by reC
so my solution might not work since i don’t have my L5 yet (duh!) but in theory it should work if you get a micro-usb to usb-c adapter or if you have one already. if it’s too much then you just get a power bank.
for portable power reserves (in my car) i use a “big” solar chargeable acid-lead all-in-one jack-of-all-trades battery. (12v @ 7Ah i think it is) can power 4 led 4w(12v@300lumes) LED e27bulbs for 6hrs(more or less depending on the charge level). also has radio/usb-ports etc. chinese but hey !
i hope it’s not been too much all at the same time for you and i hope you’ll make the right choice for your needs …
PS: i’m a Blackberry Q10 user currently (yes it has a hot-swapable battery and i have an extra 2 left just in case + the portable-mini charger i linked to above (just in case for ultra portability).
… but it’s not open-hardware/free-software friendly !