Powerwerx MEGAbox2 Portable Power Box for 30-70Ah Bioenno Batteries

I use mine for portable Ham Radio setups. I have a Valance 38 AHr battery in mine and there is plenty of room for extra power cables and misc USB cables. I have used all of the connections and the USB connections. It’s nice to have the on/off switch to eliminate any phantom loads.

This unit helped me out when my car got a flat tire one night.  I had the Megabox in the back seat with a Bioenno Power 50Ah. I turned on the cool strobe lights on it and the trooper saw me from a mile a way with the LED lights on it.  Said it was super bright. Great product!

I do like the product, it's well made and saved me a lot of time making my own.

My only comment is about the placement of the 12V auto socket and the USB sockets. These three protrude a LOT in the height department. If we were to move all three vertically along the left edge of the lid, we'd have the 3 tallest sockets in a single column. The on/off switch could go right in the center (line between the padlock hole and the handle, between the reinforcement ridges).

This way, we'd have a product that's not only meant for bioenno, but it would easily accommodate other batteries, such as 3 or even 4 of the popular 20Ah packs in parallel. These packs are 7.1 x 3 x 6.8 (incl terminals), and by moving the DC USB sockets along we allow at least 3 of them together. We only need 9 inches of clear height to accommodate them.

Better yet, if we moved the flashlight along with the switches to the latch side of the box (OR rotate the whole "new" top layout by 180 deg), we'd keep all the protrusions "together", and likely allow for a fourth 20Ah pack, potentially opening an 80Ah option total.
I'm going to modify my box a little to allow 3 packs, by moving the on/off switch to the centerline and drilling a 1 1/8 in hole where the switch used to be, moving the tallest DC socket (USB A + C) to that spot. I will be left with an open hole which I'll simply mask out. This will give me enough clearance for 3 x 20Ah packs.

I do have an ammo box of exactly the same type and might attempt the proper drill pattern in the future to demonstrate whether my ultimate plan is correct. So far, looking by the "maximum possible interior" dimension of 12.5 in this all seems doable if only we move the protruding components into a single column. In the worst case if a fourth pack didn't fit height-wise, we should easily be able to find a smaller pack (in the 10-16Ah) range that's <3 in wide, 7.1 in long and <6 in tall.