I'm working out a low voltage (12VDC) lighting system for the playhouse in my back yard I built for the kids. I am going to occasionally charge a small 12V deep cycle battery and connect it to a simple system in the play house. The system is basically battery to a mechanical timer switch (so they can't leave it on too long) to a single 7 watt (60 watt equivalent) 12VDC specific light bulb. Nothing else on the circuit. Total length of the circuit from battery connection to bulb is less than 16 feet. Online calculator I found says I can go 21 ft with just a 1% voltage drop with 18AWG wire at 1A or less. It will look like this. Anyone see any issues with it as designed? Any changes I should consider?