It's not often that we see a DIY battery box as well-executed as this one. The creator thought of almost everything!
First, gotta love the unique paint job and style. The box is used as a power source for the creator (a DJ) at music festivals and events.
You can see the internals from a couple of different angles:
There's a Renogy solar charge controller (paired with an external monocrystalline panel, not shown), a 400w inverter, and some various parts to both get the power out of the box and to monitor the charge on the battery. This box can only be charged from a solar panel as well, only the creator noted in comments on Reddit (link below) that he intends to build a newer version that can be charged from a 12VDC source.
According to its creator, the "juice box" is portable in name only. He comments on Reddit "this thing weighs like 100 pounds." Buried in the comments you'll also find discussion about the cost of building a similar box with a sale price of $400-500, only it's not at all clear if that price is materials only or materials + labor.
It's also important to note that this device does not have any sort of ventilation system. This is important because batteries can emit hydrogen gas and the electronics inside the box need air to circulate in order to stay cool. The creator points out that he usually leaves the lid off the box to ensure no gas build-up, as well as keeping all the internals running cool.
Our point in talking about this box on our blog isn't to compare the ArkPak to a cool, DIY battery box. Our company spent substantial sums engineering and designing the ArkPak over a period of years, and it's neither fair nor particularly useful to compare our device to this one.
All we want to do here is recognize a job well done on our blog, a blog that's all about portable power systems. Kudos to the Juice Box! (the creator's username on Reddit is "xxbiohazrdxx")