Understand Solar Energy readings

[Lotuscamper]

We had the solar installation for 6 months and I have had the converters explain what is showing on the app ?
To be honest I still don’t understand what the hell this is saying ? I am a little dim and too ashamed to ask again as we have had problems with leisure battery and alternator in the last 6 months to add to our woes

The picture I have taken is a typical read out even with todays sunny weather
Anyone can give a real idiot guide to what I should be reading /understanding?

 

[TallPaul_S]

Do you know what your battery state of charge is? As if it's full, you won't be getting any solar watts going into your system as there's nowhere for it to go. That 0.7a could just be the draw of any small devices powered on.

 

[Stay Frosty]

Is this at night?
Sorry to be absolutely no help at all but I've installed solar and while the B2B and leisure battery are both Bluetooth the only sense I can get from what's actually happening is by looking at the Renogy shunt display across the leisure battery which tells me exactly what is going into or out of the battery in real time.

 

[DXX]

We had the solar installation for 6 months and I have had the converters explain what is showing on the app ?
To be honest I still don’t understand what the hell this is saying ? I am a little dim and too ashamed to ask again as we have had problems with leisure battery and alternator in the last 6 months to add to our woes

The picture I have taken is a typical read out even with todays sunny weather
Anyone can give a real idiot guide to what I should be reading /understanding?

View attachment 247736

Solar power generation to battery is 9w (18.74vDC x 0.5A) = actual 9.37W

Battery status is Bulk charge, so not fully charged yet, hence it’s taking the 9W available to it. 9w (13.24vDC x 0.7A) = 9.268W.

The tiny difference between 9.37W and 9.268W is probably DC loss due to resistance.

There are no consumers drawing power from the battery as the current is 0.0A.

 

[TallPaul_S]

There are no consumers drawing power from the battery as the current is 0.0A.

That's just the load output on the MPPT, not the entire system load. But I'm betting that, unless the panel is faulty, the battery is at or nearly fully charged. I'd expect much more than 9w in this weather!

 

[Lotuscamper]

Solar power generation to battery is 9w (18.74vDC x 0.5A) = actual 9.37W

Battery status is Bulk charge, so not fully charged yet, hence it’s taking the 9W available to it. 9w (13.24vDC x 0.7A) = 9.268W.

The tiny difference between 9.37W and 9.268W is probably DC loss due to resistance.

There are no consumers drawing power from the battery as the current is 0.0A.

Ok and I am still scratching my bald patch ! Is the solar panel delivering what it’s supposed ? We had no leisure battery power yesterday and we think as the van was sat for couple of weeks battery was drained ?
So our lesson is we need to hook up every week when not using van ? But then I thought the solar panel was adding power ?
I am confused I am a real dummy !

 

[Bav]

What was the state of charge when you took the screenshot from the VictronConnect app?

 

[TallPaul_S]

Ok and I am still scratching my bald patch ! Is the solar panel delivering what it’s supposed ? We had no leisure battery power yesterday and we think as the van was sat for couple of weeks battery was drained ?
So our lesson is we need to hook up every week when not using van ? But then I thought the solar panel was adding power ?
I am confused I am a real dummy !

What's your battery size, type?
Do you know what the current level of charge is?
What's your solar panel type, size?

If your battery isn't being charged and that's all you're seeing from solar, your panel might be faulty. Very common with semi flexible panels.

 

[Lotuscamper]

I don’t know my battery type I know the solar panel was 100w and it’s a rigid type not flexi ?

Does this picture help? Having spend £1k on the installation I like to know if we are actually getting some benefit ?

 

[TallPaul_S]

So you've had 190Wh out the solar today, which is nearly 16Ah. I'd say your battery is fully charged. Seeing little or no watts is normal when the battery is full.

Turn on something that draws a few amps (the more the better) and you should see your wattage from the panel increase as it fills the hole left by the device drawing power.

 

[Stay Frosty]

So going back to my shunt display would that not be a much simpler way of knowing what's actually going on at the leisure battery at a glance rather than the mind games of blue tooth graphs that may actually be wrong if the device software needs updating?
My Roamer battery will tell me via Bluetooth that its capacity is way in excess of its 230A whereas the shunt display has a much better idea of what's available.

 

[Skyliner33]

That's just the load output on the MPPT, not the entire system load. But I'm betting that, unless the panel is faulty, the battery is at or nearly fully charged. I'd expect much more than 9w in this weather!

The battery can’t be nearly fully charged or the MPPT would have changed from BULK to ABSORBTION.

 

[Skyliner33]

I don’t know my battery type I know the solar panel was 100w and it’s a rigid type not flexi ?

Does this picture help? Having spend £1k on the installation I like to know if we are actually getting some benefit ?

View attachment 247742

The type and size of battery would let people give better advice. Can you take some photos.
In the picture you posted in each bar the bright white bit is bulk charge. The middle bit is when it’s nearly full and so has dropped into absorption. The darkest part at the top is when the battery is full and it’s gone into float.

 

[ginkster]

You say it’s a typical reading but the history picture you added appears to show it’s not typical compared to 2-4 days ago. Was something (the fridge maybe) turned on yesterday? That would explain the sudden increase in bulk charging today and yesterday. Your first picture is starting to get a little late in the day (16.14) and if there is any (even a tiny corner) shading on the panel the watts will decrease massively combined with a lowering sun angle. Otherwise the history page shows good panel voltage, max wattage etc so looks ok with the limited info available. My hunch is something is drawing power over the last 2 days and the panel is just about keeping up, but not completely today. Pics of the setup and battery would help.

 

[Drive Wayne]

My van fridge is permanently on, today was a good day for fridges in vans to suck power! Mine certainly did, as my LB topped up, the fridge pulled it down, no driving today. Bulk charge all day, LB currently at 80%. I would say your figures look good to normal. I use the same victron gear as you @Lotuscamper with a 200Ah LB, 180 watt panel.

 

[Lotuscamper]

My posting of this question is really two fold ? I don’t understand the solar panel workings & how our leisure battery is performing ?
Last Sunday after 30 mins at a site we lost power to habitation area, the battery level was very low. We think as not used the van for a couple weeks battery was discharged and we should had the hook up to recharge the battery ?
I would have thought the solar panel was doing that ? Anyway I am confused

 

[Drive Wayne]

My posting of this question is really two fold ? I don’t understand the solar panel workings & how our leisure battery is performing ?
Last Sunday after 30 mins at a site we lost power to habitation area, the battery level was very low. We think as not used the van for a couple weeks battery was discharged and we should had the hook up to recharge the battery ?
I would have thought the solar panel was doing that ? Anyway I am confused

Can you give us a picture of your Leisure Battery?
Is it a lithium or an AGM?

 

[roadtripper]

I would have thought the solar panel was doing that ? Anyway I am confused

How far back does the history in your Victron MPPT go and if so what's the charging history the week before that Sunday?

If the van was unused for a couple of weeks how did you leave it? Did you turn off the leisure battery (if you have an isolator for it)? Did you leave any heavy consumers such as a fridge/WiFi/dash cam running from the leisure battery? Does the solar panel have a clear view of the sky without shade?

 

[Lotuscamper]

How far back does the history in your Victron MPPT go and if so what's the charging history the week before that Sunday

It’s AGM battery I can’t take picture as away but see photo of history of app
With the last few days sunny weather but van is parked under a palm type of tree but south facing

 

[TallPaul_S]

50Wh is only 4Ah which, if you've something running, even at half an amp, will drain the battery faster than the solar can refill it.

0.5a drain for 24hrs is 12Ah. Solar is only putting in 4Ah. That's an 8Ah deficit. Over a week, that's 56Ah. Which is half the capacity (or all the usable capacity) of a 110Ah AGM battery.

So, it's very easy to end up with a dead battery.