Watts out

[Wxboy]

Doing some experimenting with my new battery switch it looks like when the controller is showing 7 watts it's really outputting zero watts.  Is this caused by drift within the Classic's meter?  If so, will it drift further? 

I've come to this conclusion by flipping the switch to a battery that has been sitting with no load on it.  If the controller is reading less than 7 watts then the battery voltage on the battery I'm switching to drops.  7 watts or more and it holds steady or increases. 

Is there a way for me to calibrate the zero point?

[Westbranch]

Is the 'going to' battery fully charged?  what is the voltage measured by DVM?

[boB]

Doing some experimenting with my new battery switch it looks like when the controller is showing 7 watts it's really outputting zero watts.  Is this caused by drift within the Classic's meter?  If so, will it drift further? 

I've come to this conclusion by flipping the switch to a battery that has been sitting with no load on it.  If the controller is reading less than 7 watts then the battery voltage on the battery I'm switching to drops.  7 watts or more and it holds steady or increases. 

Is there a way for me to calibrate the zero point?

Try turning off the input (PV) breaker and see if you still get 7 watts.

Yes, it can be off or drift as you say, but it's very good.

Any drift that may occur cannot be "adjusted" but in solar mode, it might re-calibrate
itself once in a while.  Now I'll have to check that further but it can re-calibrate during
sweeps.

boB

[Wxboy]

Westbranch I tried it tonight on both battery banks.  Both of them were roughly 90% charged at the time. 

boB, I noticed this 7 watt differential both yesterday and today but I will try flipping the breaker next time to see if there is a change.  It will be interesting to see if this does vary from time to time. 

I'm sure people with large systems wouldn't pay attention to this but when you have one panel and a small battery bank things are more noticeable.  That and the fact that I test everything I have from top to bottom doesn't help.

Thanks for the response.  It's not a big deal, my Prius reads 2.8 mpg too high on the display but I know it so I just compute it out when looking at the gauge. 

[boB]

Turn off the PV input breaker and see if it goes to zero most of the time.

When solar PV is on and you turn off the battery breaker, it ~may~ be measuring
its own power draw.  Can't remember exactly if this is the case.  I will check
my 200 on my desk here.

boB


PS   AHA !!   Yes, I think it is measuring its own power draw at least to some extent.

Here, I turn it on, (wind mode ) using a power supply on the bench and it's charging 387 watts.

Then, I turn off the battery breaker and it shows 8 watts !  Very close to your 7 watts.

If I then turn off the in (PV) breaker, it goes to zero watts on the display while still
running  (BULK MPPT).

boB

[Wxboy]

boB, I think I may not have been clear enough with my original post so let me start over.  The display will read zero and does so quite often.  The 7 watts is what I determined to be the point where the battery voltage will not drop when I switch the Classic to be charging that battery.  For example, battery switch is set to #1 and battery 2 is reading 12.50 volts with no load.  So if I then switch to battery #2 I would expect the voltage to either drop if there is no output from the Classic due to the draw of the Classic, stay the same if PV input matches the Classic's draw, or the voltage should rise if enough watts are coming out of the charger.  The point where the voltage remains the same when I flip the switch looks to be 7 watts or so on the display.  I thought the Classic showed actual watts going into the battery, as close as possible anyway, but maybe it is showing every watt coming from the panel so it's at 7 or 8 watts that current actually starts flowing to the batteries once it overcomes the Classics power consumption?  Or the meter is just off by 7 or 8 watts.  I'm just trying to understand it. 

[boB]

boB, I think I may not have been clear enough with my original post so let me start over.  The display will read zero and does so quite often.  The 7 watts is what I determined to be the point where the battery voltage will not drop when I switch the Classic to be charging that battery.  For example, battery switch is set to #1 and battery 2 is reading 12.50 volts with no load.  So if I then switch to battery #2 I would expect the voltage to either drop if there is no output from the Classic due to the draw of the Classic, stay the same if PV input matches the Classic's draw, or the voltage should rise if enough watts are coming out of the charger.  The point where the voltage remains the same when I flip the switch looks to be 7 watts or so on the display.  I thought the Classic showed actual watts going into the battery, as close as possible anyway, but maybe it is showing every watt coming from the panel so it's at 7 or 8 watts that current actually starts flowing to the batteries once it overcomes the Classics power consumption?  Or the meter is just off by 7 or 8 watts.  I'm just trying to understand it.

What do you mean by "battery switch" ??  Are you running two different battery banks and switching the classic (while on) from one to
the other bank ??   If so, and if the battery bank voltages are different from each other, then you may be seeing the difference because
the Classic will note what the battery current draw is when it goes from Resting to ON to take into consideration the draw needed
by the Classic.  The Classic definitely takes some power from the battery to run and ~should~ show only what it is putting out
to the battery above and beyond that draw.

That being said, it CAN drift some, but in my experience, it will usually take a while to drift, if it is indeed going to drift.

Also, the amount of change in watts can only be as small as 0.1 amps or volts when multiplied together which is where
the watts display comes from.

boB

[Wxboy]

Yes, I have a marine battery switch installed and I am switching from one battery bank to the other while the Classic is in Insomnia mode.  If battery bank 2 is reading 12.50v under no load and then I switch to that battery bank and the Classic is putting out 7 or 8 watts then it will remain 12.50v.  If it's putting out 6 watts or less then I'm seeing a reduction in voltage, 12.49, 12.48 etc. so to me it seems like the Classic is drawing more than it's putting out even when it's reading 6 watts.  Maybe it's from the drift but it is only a few months old.

[Halfcrazy]

You say you are using "Insomnia" this basically keeps the Classic awake all the time and will increase its power consumption at no power greatly. The Classic when "Resting" uses ~3-4 watts when in "Insomnia" it is going to use ~25-30 watts. Insomnia was intended for Hydro mode to give them time to open and close water valves and have the Classic awake ad ready.

If I am reading this correctly the issue is you are switching between 2 separate batteries and the voltage will not change when you switch?

I would suggest that to switch between 2 separate batteries the Classic should be powered down then the switch should be made and power the Classic back on. Also I would suggest if this is a solar array that "Insomnia" not be used as this will make weird behavior show up in solar mode.

Ryan

[Wxboy]

Halfcrazy, I know that Insomnia mode consumes more power when no power is being generated so I turn it on in the morning and off in the evening.  I use it to try to capture lost power when the sun is behind the trees in the morning and early evening and only 1-15 watts are coming in.  Even on overcast days I would rather capture those watts then lose them. 

I don't know how many watts the Classic is consuming in Solar/Insomnia mode but it doesn't seem like it's anywhere near 25-30 based on the voltage drop.  If it was 25-30 watts I think I would see a much larger voltage drop when switching back and forth between batteries.

No one seems to understand what I'm saying about the Classic not adding power to the batteries at less than 7 watts indicated so I'll drop the subject.  I guess I would need a Tri-metric or something actually measuring current flow to know for sure but battery voltage seems to be a pretty good indicator to me. 

[Halfcrazy]

Basically the Classic should harvest any available power above and beyond what is required to run itself. If "Insomnia" is used the Classic can actually consume energy instead of making energy. The only true way to know would be to install a "Fluke" style meter in series with the output of the Classic and see if you are running positive or negative when using "Insomnia" like you are.

The Classic may leave a watt or 2 on the table first thing in the AM or last thing in the PM we do error a few watts on the higher side so we do not spend a lot of time clicking on and off. I would say this is < 5 watts max.

[Vern Faulkner]

The Classic may leave a watt or 2 on the table first thing in the AM or last thing in the PM we do error a few watts on the higher side so we do not spend a lot of time clicking on and off. I would say this is < 5 watts max.

I find the Classic 150 clicks on or off frequently, sometimes as often as every 20 seconds, an hour and a half morning/evenign and worse during cloud.
I've searched for a way to change the interval, but I can't ...

[Wxboy]

Vern, as Halfcrazy said the Classic is resting during times of low solar input(approx. 12 watts or less on my 150).  About every 20 seconds it wakes up to look for solar input greater than 12 watts.  If it doesn't find it then it rests again for another 20 seconds.  The cycle continues until the input is high enough to wake it up or until the Classic senses the sun has gone down and it rests until morning(very low input voltage is probably what triggers this).  Once the Classic senses the voltage increase in the morning then it goes through the same cycle.  Insomnia mode is a way to keep the Classic awake and I've experimented with it and use it occasionally but I find most times it's best to just let the Classic do what it's programmed to do. 

Since I have a small system(255 watts) if it's a very dark rainy day and the classic never sees the power it wants I just shut it off until the next day or until the sky gets brighter. 

[boB]

Try this...

Go into the TWEAKS menu, MORE, and turn on INSOMNIA.

See if that helps the clicking.  Please let us know if that helps.

boB