Leaving batts unattended while charging is a bad idea IMO.
Li-Ion batts can and do over heat,vent etc, and cause fires.
That includes cell phones,laptops,and flashlights that use LI-Ion.
There are several vape suppliers who sell charging bags that will contain the heat
so you may want to invest in one or two if you can't stay close to your batts while they charge.
JMO HTH