Stealth charging 50Ah 12v Lifepo4 portable powerbank in my backpack

[Jack Mmkay]

Hey! I'm not an expert in electricity but I've been pondering for a very long time about how to solve my electrical needs while i travel with my van and I'd like to hear your opinions and perhaps safety disclaimers. I live in Spain if that matters.

So after consider ALL the options, this is the idea I've come up with.

I want to carry around a 50AH battery queen lifepo4 in my backpack and charge it with a 25 amp AC wall charger when I'm traveling. Id either sit at a restaurant , a library or even have it in my gym bag, charge it for an hour or two and head back to my van. My electric needs are minimal ( laptop, lights, phone, roof vent... and electric stove actually as i don't like burning fuels in a closed space)

I don't feel guilty for " Stealing electricity " as I'd just be taking 44 cent worth of electricity per full 2 hour charge...

I don't want solar because my van is low roof and I want to stay as stealthy as possible while city camping.

I have also a bluetti eb3a . The fan noise while charging is so loud its unusable for stealth charging at any public place. Thats why i wanna buy the lifepo with the external charger
Also it only charges at 10 amps from the alternator and I barely drive at all...

Apparently this lifepo4 charger has no fan and is completely silent! Great. On the Amazon website it says the battery queen accepts 25 amps, but on the official battery queen the charger they offer as a bundle is 10 amps ( too slow, would take me 5 h for a full charge)

Is my idea a fire hazard? What are some ideas along the same thought process? I'm open for reconsidering everything but my ideal is having a big fat fast charging ( or a few smaller ones) power banks that i quickly recharge here and there and can bring back to my van.
Huge thanks!!

 

[Vigo]

I would have assumed that any charger you end up with is also not very stealthy and makes fan noise but it sounds like you've got that covered.

In terms of having 600+wh on your person id say it's about as safe as it gets. Make sure the charger is not connected to the battery unless it is also connected to the wall because there's always a tiny chance of something like a partial short across the charge cord wires that wouldn't shut down the bms but would cause havoc in your backpack. Also no conductive pieces able to reach from terminal to terminal should be allowed in the same space (zipper? id check..).. but that's just generic stuff, in general i'd say it's fine!

If you're going to be frequently disconnecting and reconnecting battery and inverter you might look into something like XT90 anti-spark connectors as a way to minimize the accumulation of 'wear' or damage from inrush currents. Or some slightly more complicated 'precharge' scheme.

Most lifepo4 are fine long term charging at .5c which would be 25 amps in your case so no issue there.

You can get flexible frameless panels that would still be pretty stealthy, especially since a lot of people can't really see onto the roof of a large van anyway. Even 100w of charging would be far more over time than the couple hours here or there in a restaurant/cafe. I would at least consider a flexible panel in place of OR in addition to, your 'retail convenience charging' scheme.