Solar charging!

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Walusotu

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I have just upgradied my solar array to include a 180w and 50 w panel. They are connected in parellel and both show an open circuit voltage of around 19v.
I have a Victron 75/15 for charging. The charger to battery is fused. The wire for panels to charger has a single pole switch.
The open circuit voltage at the wires leading to the charger are also close to 19v and so there is little voltage drop between panels and charger.

I am presently in India were the sun is shining!
When charging I see a solar voltage between 14 and 17v. The maximum input after 1 day of operation was approx 2 to 3 amps but frequently less. The battery showed between 12.8 and 13.2v depending on cycling of the fridge.
Is there something wrong here?? What can I check further?
 
I may completely misunderstood but you have a fridge running 24 hours and you will be using other electric; devices, water pumps, recharging laptop, lights, if you are actually sailing then autopilot, chart plotter. Unless you define what your power consumption is it is difficult to pass any sensible comment. Your solar display only offers at maximum output during the middle of the day - assuming no shade. Being in India your fridge may be working hard, if not very hard and if it is hot you may be using your fridge, constantly opening and closing the door to enjoy cool drinks. The solar voltage data you are quoting is probably maximum values - not average (and only during daylight hours).

Superficially your power consumption and usage seem to be in balance (and I would say your fridge is working well - considering).

Tell us more

You will enjoy much more learned comments when Europe wakes up and recovers from Xmas morning - but for educated comment define your consumption.

Jonathan
 
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agree with Neeves,

however, please explain how the two panels are wired, because I *think* you may have them in a way that the 180W is actually used as a 50W.
Easy check is to unplug the 50W use the system for a day or two with the 180W only. If wired wrong, the single will work as 180W whereas the two as 2X50=100W.

Mind in Greece in the summer with 2X300W and a victron 100/30 (iirc) I break even with two fridges and other consumptions on a 43ft mobo.
fridge, a/p, lights, etc on 180W with the sun elevation not at summer levels looks like you're doing OK(ish)

V.
 
Sorry if my question seems a little dumb but I am comparing the amps readout to my previous setup which had 130w of panels with a PWM(?) charger. With the same load on the system I was seeing 5 and 6 amps of charging on the Marley HRD2 unit.

At the moment I am in COCHIN Marina using minimal power which is effectively only the fridge + led lights. I have turned off the shore power charger to test the system.

Maybe it is my unfamiliarity with the Victron system and it’s data output. Each of the 2 panels are connected together in the cockpit locker to a single +ve and -ve leading to the victron, please clarify a better way to connect.
Yesterday I did, in fact, check the system with only the 180w panel. Not significantly different.

Historically my system has worked reasonably well with plotters,Ais,radio,water pump etc but I had this crazy idea to install more power! Looks like less at present or is just an illusion.

I still believe there is something amiss that I cannot figure out. Maybe I am wrong.
 
Just to further clarify:
Domestic - 2 x 110ah
Start - 80ah

Today with only fridge working I generated 160wh of solar according to the Victron. I never saw more than 24 w on the controller.
Battery at sundown after a sunny day was 12.6v with fridge on 13.1v fridge off.

All seems very low to me and less than I was able to produce before. Surely there is something wrong.
Need to get this sorted before moving up the Red Sea.
 
Why don't you start by measuring each panel to see what voltage it give and the current with it at an angle to the sun .

If that's ok disconnect the smaller panel and see what you get over a day.
 
Just to check, 130w + 180w + 50w ? 360w total, also note that the victron needs +5v above battery v to start.
 
Vic,
I have moreorless done what you suggest before I solicited help.
As indicated in my first post, both panels show an open circuit voltage of 19v approx.
At time of highest sun the collective power output was approx 1.5amps. Seems a bit low for a battery bank still under bulk charging.
I have disconnected the smaller panel but the numbers are not much different. I suppose I could recheck this.

Daverv, the Victron needs +5v to start but after that +1 to continue. The fact that I have reading shows the Victron is working but not so well, I believe.
 
Walusotu said:
Just to further clarify:
Domestic - 2 x 110ah
Start - 80ah

Today with only fridge working I generated 160wh of solar according to the Victron. I never saw more than 24 w on the controller.
Battery at sundown after a sunny day was 12.6v with fridge on 13.1v fridge off.

All seems very low to me and less than I was able to produce before. Surely there is something wrong.
Need to get this sorted before moving up the Red Sea.
Click to expand...
Lead acid batteries? Sounds like they might be fully charged and the solar controller is just wasting the rest as heat. At morning test voltage again under load and not. Maybe try to use a bit more of the battery capacity overnight and see if the victron will put more in.

If lead acid batteries in a, 12v system, using only 50% of stated capacity for longevity, that's 110 of usable capacity with the rest running loads throughout the day. In that context, the 150Wh in one day, doesn't seem too bad to me, from 230w nominal of panels. Probably you could run more load during the day without worrying.

Worth understanding the Ah draw of the fridge and everything during the day though. Tricky without shut though.
 
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what's your continuous load? The 2-3 Amps you see going in is on top of all the continuous consumers. The solar controller if it's the bluetooth version will show you exactly how much bulk /float charge it's giving but looking at the voltage it looks like float voltage only. I have mine set to a much higher bulk voltage.
Lastly, have you tried putting your panels in series?
 
Buck Turgidson said:
No reason he can't put them in series and with an MPPT controller he might be better off with the higher input voltage.
Click to expand...
As Vics said you end up with all the panel at the lowest panel .

I know there an argument about what's best series or parellel , I have four panels all the same age , two in series two in parellel and there not been one day when the different between them been more then one or two Amps at the end if the day.
 
Does the Victron MPPT have bluetooth or do you have a cable to connect it to a laptop if its the older blue solar model? If so what is it reporting on the Victron app or Victron Connect screen on a laptop? Has the Victron app done the updates which they issue regularly? You should have a display like this.
 

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Embarrassed to say that I found a bad connection from the 180w panel? Everything now looks more normal.
With only the 180w panel connected it is producing around 80 w and 5amps at midday. Battery is up to 13v with fridge running.

However, I still wish to use my old 2 x 50w panels which I will connect in series. Is it good practice to combine these 2 arrays (1@180w and 1@100w) to the same controller?

Thanks so much for comments so far. Appreciated.
 
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