We have found a set of 12 volt outlets to be very useful in our off-the-grid cabin. While we have an inverter to provide our AC power needs, there’s little sense in stepping our DC power up to AC, then stepping it back down to DC to charge our computers, cell phones and other electronics. Most of these can be powered with 12 volt “cigarette lighter” chargers plugged into a 12 volt socket.
We’ve gotten by for a while with a 3-outlet bank that I picked up at a garage sale sometime in the past. However, it has proven unreliable. One of the cylinders cracked. Even with a binding of electrical tape, it held the plugs poorly. One of them shorted out and melted the housing. I fixed it, but never fully trusted it again. For all practical purposes, the bank has been reduced to one reliable outlet for a few months now.
I recently upgraded to a new set of outlets. This was simple: I merely purchased a socket extender for a car cigarette lighter, and modified it to our needs.
I got a set of 4 sockets, each with its own cover. One of the 3 is heat-shielded to take a car cigarette lighter (I doubt we’ll ever need that, but one never knows). There’s even a USB outlet on the other side of the unit.
I clipped the socket end off the cord, and tied it into the positive/negative wires I’d run from the battery bank to the area where we used the old plugs. The unit is fused in the plug, so I tied in another fuse to the positive line at the outlets. We now have 4 reliable outlets in a much nicer unit, and have been enjoying the benefits of it ever since.