Backup power supply

I have long had the idea of making myself a backup power source on a battery, a kind of high-capacity “Power Bank” with a voltage of 12 V. You can take it with you on a hike or fishing and charge your phone, laptop, flashlight or other gadgets there.
Yes, even keeping one at home can be very useful if your power suddenly goes out.

What is required to make a Power Bank?

First of all, the battery. The type that is used in an uninterruptible power supply for a computer. I found a 12V battery with a capacity of 7 Amp-hours. Of course, there are more powerful batteries, but I took what was at hand.

The second is a mini box or tool case. You can buy one like this at a hardware store. It is relatively inexpensive.

The third is a panel with a cigarette lighter and USB connectors. which I bought - HERE.
Everything is connected very simply. There are three switches on the panel, the first one I made common - it cuts off the entire load. The second one uses the cigarette lighter socket. Well, the third one is a socket with USB outputs. USB 5V converters are built into the cigarette lighter body itself and are not visible.

I cut this entire control panel into the side wall of the tool case.

How is the battery attached?

A layer of construction insulation is laid on the bottom of the box. The battery is on it. On the sides, the battery is also secured with the same insulation, but in several layers. The reconciliation is also pressed by a thicker piece. The battery holds up perfectly, the Power Bank is almost shockproof.

My backup source turned out to be very compact and convenient, especially for carrying, as it has an excellent handle.
I took such a source with me to the campsite and charged it there from solar panels. During the hike, the Power Bank showed only good results.