Milliwatt: Cheap choices about energy

My 12V rechargeable string trimmer died (burnt out motor windings), but it still had a functioning battery and charger controller. So, those got recycled into a solar light for our horse arena. The battery and charge controller are housed in the "bird house". A 5W panel from the prior Solar mower project was reused. I ordered a 12W, 12VDC light and timer switch. The light certainly doesn't light up the whole arena, but gives just enough light to take the tack off of the horse after a ride at dusk, and to hook up the harrow to the tractor.

The timer lasted about 6 months. It still works as a switch, but now the timer doesn't work.