Are these loose cells or do they have built-in USB charging?
The latter are pretty no-worry as I understand it, just plug in a charger.
If they don't have a built-in charger, than a certain amount of caution and do-diligence is necessary.
Some Li cells can be overcharged, to unpleasant results.
Here are some links that speak to the safety of charging Li batteries:
[
www.18650batterystore.com]
[
www.large.net]
[
www.ehs.washington.edu]
Some of this you may already know, so if so — never mind.








I am that Masked Man.
All you can do, is all you can do.
There’s trouble — it's time to play the sound of my people.
Your boos mean nothing to me, I've seen what you cheer for.
Insisting on your rights without acknowledging your responsibilities isn’t freedom, it’s adolescence.
I've been to the edge of the map, and there be monsters.
We are a government of laws, not men.
Everybody counts or nobody counts.
When a good man is hurt,
all who would be called good
must suffer with him.
You and I have memories longer than the road that stretches out ahead.
There is no safety for honest men except
by believing all possible evil of evil men.
We don’t do focus groups. They just ensure that you don’t offend anyone, and produce bland inoffensive products. —Sir Jonathan Ive
An armed society is a polite society.
And hope is a lousy defense.
You make me pull, I'll put you down.
I *love* SIGs. It's Glocks I hate.