Batrium Watchmon free software to monitor your 18650 setups Screenshots Hunter's comment you kinda need the hardware to use the software thus the software is free but it's a radical free piece of software

GOAL ZERO YETI 3000 LITHIUM PORTABLE POWER STATION WITH WIFI Screenshots Hunter's comment sure it's overkill, but it's the premium offgrid battery they have and the best of all is that you can charge this