aaron- not sure of your battery set up, but Matthew raises a good point - ie the safety of Li type batteries. Unless you know what you are doing wrt handling / charging ‘em, take real care, they are nothing akin to old fashioned Lead acid etc.
I’m ex airline, and every bloody year we’d have 2 days SEP (safety & emerg procedures) where the problems of Lithium batteries on board would be covered... each year it seemed the rules would change / tighten up. Many videos of them spontaneously combusting (laptops / phones etc) - once thermal runaway starts they’re VERY hard to extinguish... basically cooling the core is the only way possible.
And one for you Matthew... cheap (Chinese phone) chargers - a real concern!
Sorry - may be totally out of order here, just do take care.