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Solar question-help needed

S

Stea

New member
Im a solar newby and need some help.

Currently have a single 100 watt panel going to a charge controller and then to 2 12 volt deep cycle batteries. (Next summer the plan is a total of 8 100 watt panels and a lithium ion battery) From there i use a 3oo watt inverter to power a cell signal booster.

When Im there its fine because I bring a generator to power everything and I usually bring an extra battery with me.

I now have a cell enabled game camera that I am using to keep an eye on the yurt. It fantastic. It seeds pictures to my phone when there is movement or when i send a command to it.

But, in order for the camera to work the cell booster needs to be running. I dont want to run the booster 24/7 because I dont think I have enough solar capacity at the moment to keep the batteries charged. I plugged the booster to a timer to turn the booster on at certain times of the day to conserve battery but obviously the timer is 120 volt and the inverter is still running the timer. The inverter never does pull enough juice to get the cooling fan running but obviously it is still converting 12 volt to 120 volt for the timer..

I have found a 12 volt timer i could use BUT can i use the 12 volt timer between the batteries and the Inverter?????? That way there would be zero power used except when I set it to run.


Thanks for any help.
 
Interesting idea/setup. If you could post a link to your 12v timer spec's I might be able to comment more.

Also, what inverter are you using? Do they give a standby current usage or just the peak efficiency? Or do you have some current monitoring on the DC side going to your inverter? Any of those can give you an idea of how much energy you're 'wasting' by leaving the inverter on 24/7...
 
Now you're thinking! Inverters have that standby current draw, so using that voltage regulator (buck converter) for your 5 V electronics is an excellent idea since you'd just be rectifying the AC back to DC anyhow. As long as the voltages match and the regulator can supply as much or more current then needed it's fine--the load (your booster) will set the current used.

One big thing to watch out for is nominal vs actual voltages--'12 V dc' solar means the actual voltage can vary between 10 V up to 18 V dc on the panel side! With the batteries hooked up, you probably won't get above 15 V though. The voltage regulator is spec'd for up to 23 V, so that's fine. The 12v timer just says '12 V dc' so I can't really say--someone else selling the same product might give better information, or there might be hints in the reviews.
 
One thing to double check--look at the booster power supply and verify that it's outputting just 5 V 1 amp. In some images of your booster there's a '12 V' symbol on there along with the '5 V'--could be just an internal thing but it doesn't hurt to double check...
 
I think I am going to try the panel to controller to Battery to 12 volt timer to inverter to booster set up.

Not sure if I want to hack up the booster cord on an experiment. lol
 
You will want to make sure your controller can handle 800 watts or consider configuring your array for 24 or 48 volts by wiring them in series.
 
Jafo, right now it's just a cheap off brand 100 watt panel, a cheap controller and a couple 12 volt deep cycle batteries.

When I do the "real" system next summer . I will probably buy a package deal so it will all match up.
 
I second the idea of using DC->DC converters instead of 120V if you really don't need it. They make them for various laptops, along with the stuff already show here.

However, it's also worth just running it all the time and seeing if it keeps up. It might seem wasteful, but the solar power is free at this point. Naturally it will vary by time of year. If it keeps up in the darkest average times, you can avoid all the extra complexity.
 
Also, adding a second cheap panel that's mostly compatible is probably easier and cheaper than all the timers, etc. Or trading the one you have and a little cash for two that are compatible and can be wired in parallel.
 
Just playing with the components right now. In the spring i will get a full system in and then just powering the cell system and camera won't be an issue.

Snow has started to fly up at the yurt so the best I can do is maybe trying the 12 volt timer to limit the time the inverter and booster run. However, it's been over 7 days now and I'm still up and running so maybe the one panel is enough or its just adding extra time until the 2 batteries drop in voltage.

We shall see, I don't think I will be able to get up there for a couple weeks.

I sold the snowmobiles and bought tracks for the side by side at the wife's direction . She didn't like the snowmobiles.

 
If you don't mind, please update us on how well that works in deep snow. I have been contemplating buying one, but only if I can ride it in like 3-4 feet of snow. :)
 
Just thought I would post an update..

System dropping the voltage to to 5 volt is working fantastic.

The 100 watt panel is keeping the battery charged and Im actually powering the booster 24/7.

Jafo no update on the side by side with tracks yet. Just a skiff of snow so far. Drove up yesterday in the truck.
 
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What stepdown are you using for the 5v? Do you have a photo of it? I am considering doing the same thing.
 
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