For example, when you're camping or at another event with lots of people around. There's nothing quite as abominable as a fleet of autos chugging along in a loud cacophony.
If you have been to burning man you know there are things way more abominable.
That said, I agree cost is not the priority. Convenience is.
We started camping w/ a battery this summer and I'm definitely going to add solar charging. For me, the allure is to have the battery charging silently, and while we're away from the campsite.
https://smile.amazon.com/gp/product/B01M3S00H0/ref=oh_aui_de...
I used it while camping for the eclipse, and only had to charge it once every few days, and that was with charging all sorts of other devices as well.
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From a professional standpoint I'd nag about
> the battery is laid into the tool tray. Plenty of extra space in this toolbox, which protects the system from dust and the sun.
A closed box is not a good place to keep actively cooled electronics; less so when it's a black box in the sun.
If you seal your box in a humid environment, the cool night temps can cause condensation, so ventilation of the box would be useful to prevent this (as well as provide for active or passive cooling of electronics) or throw in some silica gel packs.
If you suppose a 12V 420Ah battery, its capacity will be of 5kWh. That would require at least 0.5l of fuel. But with a typical efficiency of 30%, it will require 1.6l, and not 0.1l.
If you have money, you can buy integrated solutions like the Xantrex XPower Powerpack 1500 + regulator + solar panels.
Let's keep in mind that a car alternator has 0.5-2kW and you need to burn <0.1l of gas to charge that battery once with the alternator. I'm not sure its worth all the extra equipment and cost to go full solar.
Edit: The solar panel probably gets you 360Wh to 900Wh per day, depending on how sunny the region you live in is. This is not enough to run a household refrigerator, but enough to charge your phones or laptops and some lights.