Always on/charging USB devices - looking for more education

Okay, last one for tonight folks. I promise.

Another project on my list is one that I'm not even quite sure how to google properly. I'm not even sure it's possible without spending oodles of silly money.

Here's the details:

• I do volunteer SAR work outside of my normal day to day job.
• A lot of our equipment is migrating to rechargeable format (no more alkaline batteries).
• Just basic USB charging.
• Items as simple as rechargeable headlamps and rechargeable FRS radios.
• If possible I'd like to set something up in the back of my 4Runnner that would keep these few devices charged but without draining my 4Runner battery when the vehicle is not on.

I hope that makes sense. I'm not talking about something like a mole device to physically hang the devices on. I'm asking about the electrical aspect. Is there something I can install that would keep these devices charged, but not drain my actual vehicle battery when it is not in use (and please don't say something like just use a 25,600mAh power bank) My hope was that I could literally leave something in the vehicle that would keep these small devices charged, without have to charge said charging device itself.

So, ya, I'm looking for any pointers on how to properly research/read up on this so I can learn and figure out if it is viable for me or not.

Thanks again.

 

You have a 12V outlet back there that’s on only when running. Can get a 12V outlet pigtail and wire up whatever you need

 

Oh brilliant. I did not know they were only on when running. That actually pretty much solves it.

Both the 120v and cigarette lighter follow this set up? On only when running?

If so then I can just simply connect a power bank to the 120v and then charge my USB devices off that power bank with no fear of draining the battery when not running.

 

The 120V requires you to push a button every time you turn the vehicle on. The 12V does not require that. How many USB devices do you have to charge?

 

Two. Three tops. An FRS handheld radio and one (sometimes two) headlamps.

I suppose I could even go something like this: https://ainope.com/collections/car-charger/products/usb-car-fast-charger off the 12V so I don't have to worry about the button pressing.

 

That would do it. They’d always be topped up

 

Thanks. Can't believe it was so simple. Had no clue about the on/off status of the rear 12V.