Vandweller Forum

todays playing with solar

tested the panel to see how it was working,in direct sun 21+ volts and 4.5+ amps so all good,my extension cord the volts stayed the same and the amps dropped about 0.03

panel with some maple limb shadows the volts stayed high but the amps dropped a lot 1.8

controller was saying 14v 0.5 amps,so i dont know,walked away and then made sure the main was off,had a look and it read 17v

this controller displays the battery voltage 0.2 volts higher than it really is,would that lead to chronic under charging and should i get a hold of renogy?

this is all sternwakes fault,if he didnt keep saying 14.7 14.7 i would just plug it in and walk away with blissful ignorance but no i'm out there worried about 0.2 volts

my main "Gary" worry is i need a 20+ foot wire run just for my stereo memory so i can shut the main off and not lose my settings

Mine has been working well for several months. It seems simple and reliable for my installation.

I have two, 100 watt panels, flat mounted on the roof of my truck camper. Two, 55ah AGMs under the bunk. My power consumption has been modest, but I have just introduced a 700 watt inverter and small fridge, so after a week or so, I will have a good idea about how things are running. 

So far, so good.

But if you think your $20 controller has a chance of ruining an expensive battery, then yes, give it away and buy a nice expensive $200 controller with all the bells and whistles.

17V is excessively high unless you're reading panel voltage. Panel voltage is not your worry, the voltage/amps going into the battery is.

(11-19-2018, 03:33 PM)B and C Wrote: [ -> ]17V is excessively high unless you're reading panel voltage.  Panel voltage is not your worry, the voltage/amps going into the battery is.

yes,pv voltage

beginner solar,this is the first panel and controller i have touched so i dont know what is or isnt supposed to happen or any characteristics thus 100w panel,$20 controller,napa battery learner set up

one thing for sure,i dont have good sun in my current location,4-6 hours

If you can tilt the panel towards the sun you will get a bit more solar energy, maybe twice the amperage for most of those 4-6 hours. It makes a huge difference.

Again, PV voltage will always decrease with a higher load, that reading tells you it's working. It should range between 13 and about 20 or so, till you lose all sunlight, and it will drop to 0.0 overnight. 

Amperage coming in will change up or down with various loads, and the amount of solar energy available, but will also drop to 0.0 overnight.

Percentage, well...its a guess. Mine is all over the place. But tends to stabilize around 100% by the end of the solar day.

time to take the next step,which i fear is maths

so what is the easiest wam-bam method to determine close enough the amp hours consumed by a electrical device?

Most things say what the voltage and consumption is on them somewhere. Then there is a Killawatt for 120 volt items or a amp meter for 12 volts items. Lastly if your batteries are in float and you have enough solar you can see the output jump by the items consumption.

So if my batteries are drawing very little amps and I turn on something the remote meter sows me how much more power is needed to power it. Easy for me because I have enough solat to power almost everything in my rig in full sunlight. I turn on the A/C and it will jump 30-35 amps, two will push it up to 70 amps.The controller will try to hold the voltage until you out pace the output of the system. Kind of unfair because my system can produce up to 80 amps.

how do i do it with a 12v amp meter?

(12-14-2018, 11:34 PM)Blacktank Wrote: [ -> ]how do i do it with a 12v amp meter?

Deep sigh, long pause............