Solar stats; does this look correct? (1 Viewer)

[Damian]

I have new setup with a 200W panel going to a MPPT 75/15 controller and 2x 100AH AGM batteries. It's been nice and sunny the last couple of days and the panel has been doing a good job of bringing the batteries up to charge but I've never seen anything like 200W in the stats (15W has been the highest).

Is this what I should expect? Or do I need to have a chat with the supplier?

 

[Burgo]

I'm pretty sure mine did the same when I did the firmware upgrade the other day.

 

[Misterg]

It doesn't look right. Are the batteries also new?

If so, some sort of software glitch seems most likely, as the batteries are being brought to full charge.

^{_{Subscribers  do not see these advertisements}}

 

[pappajohn]

As usual, the more information you have the more difficult to interpret and the more confusing.
You said your batteries are charging, that should be enough......theres nothing you can do with any other info anyway so what purpose does it serve.

 

[Camping Gaza]

Lowest volts with the highest yield,. Software glitch?. or maybe you just had more sunshine hours that day than any other. That's a stat that seems to be missing. Just keep an eye on your actual battery voltages and your consumption rate.

 

[Damian]

Burgo I've just checked my firmware version and it's v1.39. Did yours used to show larger watts during sunshine and now showing less?

Misterg Batteries are brand spanking. Might have to see about resetting.

pappajohn yeah I guess if it's charging I shouldn't complain. But it'll be nice to see the correct numbers.

Camping Gaza Today was similar figures (80Wh with a max of 13W). We're up near Oban at the moment but the sun has been great.

^{_{Subscribers  do not see these advertisements}}

 

[DBK]

View attachment 322015

I have new setup with a 200W panel going to a MPPT 75/15 controller and 2x 100AH AGM batteries. It's been nice and sunny the last couple of days and the panel has been doing a good job of bringing the batteries up to charge but I've never seen anything like 200W in the stats (15W has been the highest).

Is this what I should expect? Or do I need to have a chat with the supplier?

Such as they are the figures look fine to me because they are what I would expect to see if the batteries are fully charged. The panel has the capacity to produce 200W but only if there is the demand for it. Once the batteries are fully charged then they will just get a maintenance or trickle charge of an amp or so. The 12 point something voltages will be at night and the higher figure probably earlyish in the day. The smarter controllers put the battery through a daily cycle.

If you want to test your solar panel you need to put a load on the batteries like running an inverter at full tilt for a short period.

I'm not convinced that app tells you anything useful. A NASA or Victron battery monitor will tell you the state of charge of your batteries and the state of play with respect to charging. This is useful to know.

 

[tonyl]

Those figures really don't look right.

I was just about to point out more or less what DBK has, that the figures show power used rather than power available. However, the fact that the unit spent most of its time in Bulk mode yesterday, a small amount in Absorption and none in Float suggests to me that something is wrong if it was a sunny day. If the batteries are fully charged and the system is working correctly, the situation would be almost the opposite and it would spend the vast majority of time in Float if nothing much is used.

I use a Victron BMV as well as the MPPT 75/15 and believe the MPPT is often more useful in telling me where the batteries are with respect to charge. Basically, any day where the unit fails to get through to Float is a day when the charge has been inadequate and a day when it is always in Bulk is a failure. In my experience, the BMV seems to show a return to 100% quite a long time before the MPPT goes to Float. Maybe that's because the two devices aren't set up correctly with regard to Peukert, etc, or maybe my batteries are on their way downhill (3 year old flooded lead acid).

Where the BMV comes into its own is knowing where the solar power is actually going, as it will tell you how much of your solar is going into the batteries and how much is supplying the current load.

My unit is on v1.39 as well and showed a peak power of 83W yesterday with one panel of unknown wattage but no more than 100W from its dimensions. I was fiddling with a new TV yesterday (van parked at home), and the TV was on most of the afternoon.

 

[Lenny HB]

Just on yesterday's figurers it doesn't look right, 12.45 min voltage the batteries would have been about 60% charged so would have been able to accept a full charge from the solar. 80 W yield is only 4.7 a/h in the bright sunny weather we have been having I would have expected at least 50 a/h or 850w from the panels, obviously, it varies a lot depending on sun & cloud cover.

If they had been charging properly I would have expected to see the max voltage at 14.7v.
It could be a software glitch as others have said, easy to check with a meter.
Or it could be one of both the batteries have had it, not uncommon with AGM they are pretty useless for leisure use. Got rid of mine & fitted Gels having had bad experiences with them on the last van.

^{_{Subscribers  do not see these advertisements}}

 

[Misterg]

Such as they are the figures look fine to me because they are what I would expect to see if the batteries are fully charged

I agree in principle, but as others have said, the batteries don't appear to be fully charged so one would expect to see the solar delivering a much higher power.

This is the last few days from ours (160W Solar, MPPT 75/15 into 225AH lead-acid batteries with some driving & a small fridge running)

 

[Damian]

Very handy seeing these other setups with quite different figures. It's persisting down this morning so I'll wait for some sun and get a reading directly from the panel with my multimeter to see if things are working as expected there and get in contact with the company I bought everything from to see if they know what might be wrong.

Thanks for all your feedback, everyone. I'll post an update when I know more.

 

[Damian]

Sorry for the very long delay. We're on the road and I'd blown the fuse on my multimeter and it turns out fuses are ridiculously difficult to find when you don't have an address and can't order online.

Anyway, Mike from Midsummer Energy who I bought the controller and panel from has been incredibly helpful painstakingly taking me through eliminating various areas of the setup and even downloading the EBL manual in German to check the solar wiring. If you're thinking of buying anything solar-related and value after sales support then I thoroughly recommend them.

I measured the current directly at the panel and it was fine producing the expected full voltage and amperage in direct sunlight. The controller was reporting about 1/10th of that. The van we have (Adria Twin Supreme) came pre-wired with positive and negative cables from above the fridge to the EBL and I used them instead of attempting to run my own cables through the cabin. The negative went to a shunt behind the EBL and I branched off that to the negative of the controller.

I came across a brief mention on the Victron support forum that the controller might require an uninterrupted negative so it can accurately determine loads so I disconnected it from the shunt and wired it directly to the PV -. Problem solved!

It's early morning here and the sun is hitting the panel at quite an angle and I'm getting over 60W where my previous best was 24W.

TL;DR: the controller requires the negative be directly wired to it with no interruptions in order to determine loads.

Thank you everyone for your help.

^{_{Subscribers  do not see these advertisements}}

 

[Damian]

And here's how today looked compared to the rest of the time. Roughly 10 x better.

 

[Off da Grid]

My 255w panel even on a light cloudy day usually finishes the charge cycle by 11am charging wet lead acid 110amp hab and starter batteries. Using a Votronic mppt controller. Bulk to 14.4v, float 13.5v
The figures don’t look right, I would agree that if the batteries have had a minimal amount of discharge they would charge quickly so the figures showing yield would be low as the controller will show the power that you actually used.
If there is a only a small power load the system it doesn’t need to produce as much so can actually switch off.