Trying to understand

[Richard Hurst]

Hi all. Had my solar panel installed last week by @Roger Donoghue and he did an amazing job and I’m very happy with his installation.

I’m trying to get my head around how it work though. I can see the Watts changing but the load output stays on and no Amps being drawn. Not sure what this means. I parked my van up Friday night with the battery at 100% and have just had the fridge switched on at level 3. nothing else on or being touched. Just checked now (Sunday) and battery is at 80%. Shouldn’t it be 100% if the solar panel is supposed to be keeping it topped up??

Am I missing something?

 

[WelshGas]

Hi all. Had my solar panel installed last week by @Roger Donoghue and he did an amazing job and I’m very happy with his installation.

I’m trying to get my head around how it work though. I can see the Watts changing but the load output stays on and no Amps being drawn. Not sure what this means. I parked my van up Friday night with the battery at 100% and have just had the fridge switched on at level 3. nothing else on or being touched. Just checked now (Sunday) and battery is at 80%. Shouldn’t it be 100% if the solar panel is supposed to be keeping it topped up??

Am I missing something?

View attachment 49284

1. Ignore the Load, that is for seperate items powered by the Solar panel directly. That function is not commonly used.
2. You've had the fridge on for 2 nights and 1 ,day, just into the 2 nd day, so the panel has been charging for 1 day + today in quit warm conditions.
3. The % shown on the Control Panel is a Calculation and not very accurate. The Voltage is more important.
Just 1 Solar Panel will extend your time off grid but not make it everlasting.
Also how much power is generated is very dependant on the panels attitude to the sun so you might have 12 hrs daylight but only 6 or 8 hrs power generation.

 

[Richard Hurst]

Thank you. That definitely helps me with the load query. The panel has been installed since Monday but I drove back yesterday so obviously when I switched the van off the leisure battery showed 100% charged. Maybe my expectations are/where to high to think the panel would keep the battery at 100%, I have also not raised the roof so this has all been from with roof down, I understand that rising the roof and positioning the van in relation to the sun all has a effect on it

Definitely a learning curve. But am pleased to have one installed.

 

[Joker 1299]

Also how much power is generated is very dependant on the panels attitude to the sun so you might have 12 hrs daylight but only 6 or 8 hrs power generation.

My solar panel is very respectful towards the sun, will that help?

 

[kp64zl]

History tab is informative

That will show you how much time spent charging etc

As mentioned above load is an output direct from the controller - useful if you want to cut something off if battery below certain charge level

 

[Richard Hurst]

 

[Richard Hurst]

So checked the battery level just now 14:10 and it’s down to 40%. So that’s from leaving the van parked up since midday Saturday with just fridge on. Surely with a panel it shouldn’t of dropped this much? I’m sure that’s the same as when I didn’t have a panel. Pictures below of current readings

 

[Les]

So checked the battery level just now 14:10 and it’s down to 40%. So that’s from leaving the van parked up since midday Saturday with just fridge on. Surely with a panel it shouldn’t of dropped this much? I’m sure that’s the same as when I didn’t have a panel. Pictures below of current readings
View attachment 49356
View attachment 49357

Doesn't it say in Roger's instruction that turning the ignition on will cause the control panel to update.

 

[Richard Hurst]

Doesn't it say in Roger's instruction that turning the ignition on will cause the control panel to update.

Ah ok let me go try doing that

 

[Richard Hurst]

Doesn't it say in Roger's instruction that turning the ignition on will cause the control panel to update.

Yes I switched the engine on and then off and it is now showing 100%. Thank you

 

[kp64zl]

So checked the battery level just now 14:10 and it’s down to 40%. So that’s from leaving the van parked up since midday Saturday with just fridge on. Surely with a panel it shouldn’t of dropped this much? I’m sure that’s the same as when I didn’t have a panel. Pictures below of current readings
View attachment 49356
View attachment 49357

In what way is this 40% ?

Battery voltage is above 13 v - so that’s 100%+

But looks like your charging most of the time in daylight. Heavy battery use?

 

[Richard Hurst]

In what way is this 40% ?

Battery voltage is above 13 v - so that’s 100%+

But looks like your charging most of the time in daylight. Heavy battery use?

I meant 40% displayed on Control Panel not App. I was testing if leaving the fridge on and the vehicle parked up that the solar panel would keep the leisure battery topped up at 100%. The control panel kept showing a reduced amount each day so I was thinking that the panel wasn’t actually doing anything till it was pointed out to me that you have to start the ignition for the control panel to reset itself and show the true % reading.

 

[kp64zl]

Oh sorry I have a Beach so don’t have control panel- just the app.

 

[Richard Hurst]

Oh sorry I have a Beach so don’t have control panel- just the app.

Well at least I also now know that above 13v means the battery is 100% also

 

[TripleBee]

The thing is that the control panel doesn't see the batteries charging because it doesn't pass by the invertor.
While driving it detects the generator, while on hookup it detects input voltage. But when you just put a charger on the batteries (or 1 of them), the electronics just sees current drawn from the fridge, but not the load of the charger (in this case, the solar panel).
It would be a good thing if the invertor has a solar panel input, so it detects how much current is pushed in the batteries.

 

[Richard Hurst]

Yes definitely

 

[Roger Donoghue]

Indeed - solved above.

As Welshgas said really,

1) Load isn't used
2) Don't trust the VW control panel - it doesn't know abotu the solar. A quick engine start resets it
3) The panel will only charge if the battery needs it
4) In all your shots the battery is pretty much full
5) You are using lots of solar power as your fridge is on all the time. As intended.

 

[kp64zl]

Here is pic from internet showing relationship between voltage and % charged

 

[Loz]

it all depends on where you connect the earth from the solar charger. If you connect it to the chassis then the shunt will measure the charge put in by the solar charger and the control panel will show correctly, mine does.

 

[Roger Donoghue]

it all depends on where you connect the earth from the solar charger. If you connect it to the chassis then the shunt will measure the charge put in by the solar charger and the control panel will show correctly, mine does.

That's intersting. I've always recommended connecting the earth to the battery (generally good practice in case your chosen chassis earth fails for whatever reason). I'm doing a Cali install tomorrow and will chassis earth it and ask for feedback on the display.