Question everyone: Do you happen to still own any electronics and/or gadgets that are ONLY battery-powered? If you do, it sure does suck when you get to a point with those devices when the batteries are dead, you have no replacements, and there’s an opportunity for AC power, BUT your device has NO AC power input! OH NOES!!11!! No worries, though, you could always try to convert them to run on the grid by building a fake battery pack and hooking it up to an AC power adapter….
All Instructables user Jason Poel Smith wanted to do was run his electronic baby swing off a wall outlet, however the swing did not have a standard barrel jack. Fair warning though: this do-it-yourself hack isn’t for the faint of heart, so if you don’t feel that comfortable tinkering around with electronics, it would be best if you’d pass on this. In a nutshell, you’d have to convert an off-the-shelf power adapter and properly wire it directly into your fancy fake battery pack. This job would require soldering on resistors in order to match your target voltage necessary for the device. After your power supply is properly prepared, you can create your own fake batteries just by cutting some dowel rods, add some screws to each end to serve as contacts, wire the screws to the power supply, and finally insert the DIY battery pack into your gadget. Check out the complete set of instructions at the source link below.