Added solar power to our tractor storage building (pic heavy!)

k0ua · Nov 25, 2016

Re: Lights for the Christmas season

nikdfish said:
The wife asked if the solar charge setup in the equipment shed could support a set of Christmas lights. I took a look at the watts drawn by a small (200w) inverter and a timer, with a few strings of LED indoor/outdoor lights. The whole package looks to draw about 11 - 12 watts. We didn't have an appropriate tree, so I just set up a pole about 4' high & ran cord down to 8 stakes around the base. The lights were draped around the form & zip tied where needed.

This is what it looks like

The timer runs the lights from roughly 5:30PM - 12AM, so about 6.5 hours a night, in the vicinity of 70 watt-hours. I'll post back after a night or two's use/next day charge to report on how things balance. (for perspective, the 105 amp/hour deep cycle battery represents about 1260 watt-hours)

Nick

That looks pretty cool.

PRCWI · Nov 26, 2016

Nice!

nikdfish · Nov 26, 2016

It looks like there should be no problem running the lights this way. By 1:30 this afternoon, it had 100 watt hours more put into the battery than had been consumed since resetting the counters yesterday (225 in vs 124 out) and the charge rate was down to about 14 watts (battery getting topped off). The inverter + timer are an ongoing 3.3 watt load that jumps to 11.5 - 12 watts when the lights are on. When I checked around 10:30 this morning the total consumption since reset had been 114 watt hours.

Nick

k0ua · Nov 26, 2016

nikdfish said:
It looks like there should be no problem running the lights this way. By 1:30 this afternoon, it had 100 watt hours more put into the battery than had been consumed since resetting the counters yesterday (225 in vs 124 out) and the charge rate was down to about 14 watts (battery getting topped off). The inverter + timer are an ongoing 3.3 watt load that jumps to 11.5 - 12 watts when the lights are on. When I checked around 10:30 this morning the total consumption since reset had been 114 watt hours.

Nick

It looks like a viable solution. Of course without the invention of the LED, you would be in a world of hurt.

The first LED's were observed in silicon carbide crystals back in 1907, but it sure took a long time for commercial applications.
Light-emitting diode - Wikipedia

nikdfish · Dec 15, 2016

I made a modification to the outdoor lights/inverter setup. The combination of inverter & 120v mechanical timer was a constant 3.5 watt load, both when lights were on & when off. I also found that the mechanical timer did not like the inverter output and tended to gain a half hour + per day.

I found a nice little 12v DC timer, whose relay can handle up to 1000watts ac or dc. I paid $8 and change, delivered but you can find the same thing offered for less than $6 if willing to wait 30 days for delivery.

Along some nice programing features, a real plus is that it draws an average of about 0.01 watts when in OFF/AUTO status, mainly to keep the internal lithium battery charged. A small amount more when the relay is energized.

You can set up to 16 on/off periods & specify running on every day, every other day, weekdays, weekends, etc. I figure it will save me something like 70 watt/hours each day, running the inverter only when the program calls for the lights to be on. These timers apparently get used for lots of things like poultry watering, poultry door control, pump cycling, etc.

The small gauge wires are for powering the timer, they were piggybacked on the 10 awg main conductors.

I use small zip ties to secure the anderson power pole connection to avoid an inadvertent disconnect.

Nick