Deacon,
Your probably are not going to want to hear what I have to say, but I need to save you from yourself before you go any further.
It is really a bad idea to buy a device that uses a high-drain type of battery and not charge the batteries outside of the device, for two reasons.
The first is the battery has a finite life cycle; they are not long for the Earth, period. And the batteries used in this endeavor are being pushed pretty hard. They are like the tires on your car, and you don't want to have to replace your car every time the tires wear out. The second is an in-device charging board, which on face value is just something else to break rendering the device worthless if the batteries don't pop in and out easily. Not to mention it must be connected to a high-drain battery in order for it to function.
You fix cell phones, and I fixed radio equipment in the military as a young man. Your cell phone puts out 10th's of a watt (.1 to .6 watts say). A single 18650 can fire 50+ watts to these little coils. To put it into a cell phone perspective, you could probably get 2 watts transmit power out of a cell phone (I am guessing here), but your talk time would be in minutes before your cell phone battery was drained out.
We talk about Ohm's law, but most folks look at it in terms of numbers on a computer screen or a piece of paper. They don't quite grasp the concept of what an Ampere really is; they seem to get more fixated on Voltage as being the monster in the room, but it is the Amps that will kill you. Most circuit breakers in your house are but 15 Amp, and they will surely kill you if you get a hold of one in the wrong way. I got bit by 900 Volts by a power supply once messing around where I shouldn't have been; it hurt, and I shook for a couple of hours, but it didn't kill me. 1.5 Volts divided by .01 Ohms is 150 Amps, which is surly enough current flow to vaporize most anything in its way.
Most things only short out just long enough to open, but there are a whole lot of fireworks that can go on before it does...
I will tell you two funny stories that are true to the best of my knowledge so you don't think of me as a total pompous Ass. I knew a guy that worked as a tech at the tower of an airfield called EAF in 29 Psalms back in my service days. He tells me this story about an EA-6B pilot who flew in and got stuck at the stumps for a day or so because of weather. Being that an EA-6 is an all weather aircraft the pilot weren't real happy with the tower holding him up because of weather; lucky SOB probably had a date somewhere... At any rate, when he finally got cleared to leave, he supposedly came back over the airfield and turned on his wiz-bang boxes in the B model blowing out fuses and circuit breakers in retaliation. I always just figured it was a BS Jar-Head story passed down during beer drinking nights from one joker to the next.
It was probably 12 years ago, but I was sitting here in my house playing around with a ham radio with an 800 watt amplifier. Middle of the night, with a belly full of beer, I manage to miss tune the amp hopping from band to band. I key the the rig up and the amp squeals like a pig sending RF through out the house blowing out my home alarm system; that's right, the alarm went off and I could not shut it off! I couldn't shut it off and it wouldn't time out. I had to take my dumb drunk ass up on a ladder in the middle of the night to cut the alarm leads to restore peace in the house and the neighborhood.
Amps are the monster in the room, people. 800 Watts divided by 120 Volts is 6.66 Amps. That is all it took; just 6 .6 little Amps blew the piss out of a circuit board across the house wired to its own circuit completely independent and isolated from each other. I got to recon that pissing off an EA-6B pilot was a bad idea.
On to the next Caper,
CC