Replace 3 X LR44 battery requirement with a single AAA or AA battery
An LR44 is basically just a smaller version of an Alkaline flashlight cell.
So what you'd really need would be to graft a holder for 3 AAA or AA cells to the back of the control panel.
To use a single one, you'd need a boost converter, and that's likely to waste power without really sophisticated integration with the thing being powered.