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Solar panels not charging batteries


Southeast Boater

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Hi there,

 

I’m wondering if someone can help me. I’ve just installed 2 solar panels (in series) and they don’t seem to be charging my batteries. 

 

2 x 320w panels (mono crystalline) 

1 x 60A outback MPPT charge controller

4 x 6v Trojan t-125 240AH batteries in series and parralell connection giving 480AH in total. 

 

Ive checked all the connections. Seems fine. Battery monitor is saying the voltage from the charger is what the batteries are at. However the perctage on the monitor has stayed the same. 

 

Can someone please help?! I thought I’d have full batteries everyday with 640W of solar but so far nothing! 

 

Hope thats enough info, thanks in advance!     

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What sort of battery monitor? Model? Is it one with a shunt? If so, which side of the battery monitor shunt are the solar panels connected? If the negative lead from the solar controller is connected to the battery negative side, then it will be charging the batts, but the monitor won't know it and report the same state of charge. What voltage are the batts at?

Jen

Edited by Jen-in-Wellies
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is there any voltage from the panel into the outback? 

Have you configured the outback settings to array and battery. 

Are fuses ok, and any switches on? 

Does the outback display any charge current? 

Edited by rusty69
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have you disconnected all other means of charging, isolated the solar panels from the charge controller, checked the controller is connected to the batteries and set to 12v, then switched the panel isolating switch to ON, and then observed if they are charging?

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18 hours ago, Jen-in-Wellies said:

What sort of battery monitor? Model? Is it one with a shunt? If so, which side of the battery monitor shunt are the solar panels connected? If the negative lead from the solar controller is connected to the battery negative side, then it will be charging the batts, but the monitor won't know it and report the same state of charge. What voltage are the batts at?

Jen

Hi Jen, it’s a Victron Energy BMV-501, I believe it has a shunt. Although I’m not sure where it is or exactly what it is but a quick google says this model has a shunt. There is one cable which comes from the battery monitor and it connected to the negative terminal at one end of the battery bank.

The solar panels are connected to the controller which is then connected to the batteries. The negative lead from the controller is connected to the battery negative terminal. 

If I use power, lights, pump, inverter etc then the monitor reports the percentage going down. 

In the sun currently they are at 13.7v.

The outback controller seems to go straight to float charge every morning also. Not sure if this is because the batteries are very full or if I haven’t set the settings correctly. I entered the recommended voltages from trojans website for absorbtion and float. Couldn’t see an option for bulk charge on the outback controller.

 

Thanks for yor help. 

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19 hours ago, rusty69 said:

is there any voltage from the panel into the outback? 

Have you configured the outback settings to array and battery. 

Are fuses ok, and any switches on? 

Does the outback display any charge current? 

The outback controller says 75.3v in (and 0.7A) from the solar array. 

It says out 13.5v and 3.6A. 

I added trojans recommended voltages for charging. I’m not sure how to configure settings to ‘array and battery’? 

I haven’t added any fuses to the set up. I’m concerned I should have done? I bought a breaker but wasn’t sure where to wire that in? 

Outback says 3.6A out. I assume that’s out to the battery bank? 

11 hours ago, matty40s said:

...are you on a landline??

 

No I’m not on a landline, I’m a CC’er

2 hours ago, Murflynn said:

have you disconnected all other means of charging, isolated the solar panels from the charge controller, checked the controller is connected to the batteries and set to 12v, then switched the panel isolating switch to ON, and then observed if they are charging?

I have not tried this yet no. I will give it a go asap. A little difficult as I’m at work during the hours of sunlight! I don’t have a panel isolating switch! Should I? I can disconnect other means of power and then check. I have set the controller to 12v. 

 

Could this be something to do with the battery bank? As in the series/parallel combination maybe? I thought 620w of solar would be ample for my bank size.  

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1 hour ago, Southeast Boater said:

Hi Jen, it’s a Victron Energy BMV-501, I believe it has a shunt. Although I’m not sure where it is or exactly what it is but a quick google says this model has a shunt. There is one cable which comes from the battery monitor and it connected to the negative terminal at one end of the battery bank.

The solar panels are connected to the controller which is then connected to the batteries. The negative lead from the controller is connected to the battery negative terminal. 

If I use power, lights, pump, inverter etc then the monitor reports the percentage going down. 

In the sun currently they are at 13.7v.

The outback controller seems to go straight to float charge every morning also. Not sure if this is because the batteries are very full or if I haven’t set the settings correctly. I entered the recommended voltages from trojans website for absorbtion and float. Couldn’t see an option for bulk charge on the outback controller.

 

Thanks for yor help. 

I also have a Victron BMV501 battery monitor. Here is a picture of my shunt. It is upside down, but that is just the way it is on my boat and irrelevant. The battery is connected by the thick black cable on the right hand side. There are several thick black cables on the left hand side and these go to the 12V system (and solar controller, a Morningstar on my boat), the inverter and to the hull earth connection.

The shunt is the actual thing that measures current, via the twisted thin blue and black cables you can just about see going to the shunt. The shunt is a low value precision resistor and the twisted wires are used by the BMV501 to measure the tiny voltage drop across the shunt (50 milliVolt at 500 Amps) and from that infer the current passing through it either from, or too the batteries.

It is very important that all the things that either take in, or add electricity to the batteries are connected on the correct side of the shunt and with nothing added to the battery negative terminals but the other side of the shunt. If the negative from the solar controller is connected direct to the batteries as you describe, rather than the other side of the shunt, then the BMV501 won't know about the current the solar controller is supplying and won't include it in the charge % it reports.

You can also see two medium size red wires also in the picture. These go to the batteries and are used by the BMV501 to measure battery voltage and to supply power to the BMV501. They have 1A fuses in line to protect the BMV501.

You should have a fuse in the battery plus to solar controller connection to protect the wiring if the solar controller gets an internal short circuit. The batteries can supply huge currents that could potentially set the controller, or wires on fire. Size it for the maximum current that the controller can supply.

It is worthwhile reading the BMV 501 installation and use manuals. You can still download it from Victron. This will help in understanding how to connect to the shunt and how the battery monitor works.

I can't help with any questions on your solar controller itself as it isn't one I know.

Hopefully this will get you part of the way there.

Jen

IMG_20180423_113650.jpg

Edited by Jen-in-Wellies
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2 hours ago, Southeast Boater said:

The solar panels are connected to the controller which is then connected to the batteries. The negative lead from the controller is connected to the battery negative terminal. 

If the solar panels are connected directly to the battery, then they may well be charging, but the current won't pass through the shunt, and so the BMV501 will not show the solar charge currents.

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We have an outback 60 with 600w of panels.  It looks to me as if you are not getting much out of your panels, from the figures you quote.  You need to check that the panels are completely unshaded and see what you are getting with the sun overhead, i.e. midday.  The controller negative out should be wired to the other side of the shunt.

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1 minute ago, Boredrider said:

We have an outback 60 with 600w of panels.  It looks to me as if you are not getting much out of your panels, from the figures you quote.  You need to check that the panels are completely unshaded and see what you are getting with the sun overhead, i.e. midday.  The controller negative out should be wired to the other side of the shunt.

As The OP's Outback goes into float mode quickly my guess is that it's nothing to do with the panels or outback.   My guess is that the outback is not really connected to the main batteries but only the starter?   If you (the OP) has a multimeter checking the battery voltage should confirm.

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2 hours ago, Southeast Boater said:

I don’t have a panel isolating switch! Should I? I can disconnect other means of power and then check.

AFAIK it is good practice to be able to isolate the panels, both for setting up the controller, and whenever using a separate charging source (landline or engine alternator).  That is certainly the case for my Victron controllers (one controller for each set of 3 x 100W panels and each bank of batteries 3 x 110AH).

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3 hours ago, Southeast Boater said:

The negative lead from the controller is connected to the battery negative terminal. 

That is your problem. It should be connected to the shunt. 

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Thank you all for your kind assistance with my solar issues! 

So I have returned home and I’m not entering sure where my shunt is. I gather I’m meant to wire the negative PV from the controller to the negative side of the shunt before it goes to the batteries and the positive PV from the controller to the shunt also before it goes to the batteries?

I have a Webasto connected directly to the batteries negative and postive ends. I assume that’s should go to the shunt first also? 

Below are some pictures of my electrical installation. I have an Electrolux travel power 3.5kw, a Victron multiplus 12v 2000VA 80amp, and a Kuranda power kit which I believe houses the shunt. 

Please could some point out where I should be wiring what? It all looks a bit terrifying with so many different wires and I don’t want to blow anything up! 

My guess would be as follows, wire positive from controller to the terminal bottom left on the kuranda unit, you can just about see the red tape and behind (not shown in picture) it says battery +ve. And then wire the negative from the controller to the terminal which has the large black cable (that comes through from the bottom right) which is on one side of what looks like the shunt? 

Thanks so much D1F2141D-4635-4FA6-B16C-4A0CFAC37097.jpeg.bc9388a6140b8d59de7a270e03bdf543.jpegagain! 

886EFB61-C366-4C38-872D-70AE760D3FDF.jpeg

E73222EF-2229-4197-BACB-47C5DCC3653E.jpeg

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I don’t know whether this has any bearing on anything either. Monitor read 12.65v and 96%. I just isolated the batteries as I was planning on connecting controller to shunt. As I wasn’t sure what I was doing I posted on here. I have now unisolated batteries. Monitor reads 12.85v and 100%. This seems odd

7 minutes ago, rusty69 said:

Bottom right pic looks like a shunt connected to a negative bus bar.

So the negative from the controller would be connected to one of the terminals on the bus bar on the right hand side? The left side goes off to the negative terminal on my battery bank  

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9 hours ago, Southeast Boater said:

Hi Jen, it’s a Victron Energy BMV-501, I believe it has a shunt. Although I’m not sure where it is or exactly what it is but a quick google says this model has a shunt. There is one cable which comes from the battery monitor and it connected to the negative terminal at one end of the battery bank.

The solar panels are connected to the controller which is then connected to the batteries. The negative lead from the controller is connected to the battery negative terminal. 

If I use power, lights, pump, inverter etc then the monitor reports the percentage going down. 

In the sun currently they are at 13.7v.

The outback controller seems to go straight to float charge every morning also. Not sure if this is because the batteries are very full or if I haven’t set the settings correctly. I entered the recommended voltages from trojans website for absorbtion and float. Couldn’t see an option for bulk charge on the outback controller.

 

Thanks for yor help. 

On the outback, you need to program either the tail current at which point you wish the controller to change from absorption to float mode, or if you have a constant drain on the batteries, you can program a set period of time at the absorption voltage before it reverts to float.

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5 minutes ago, Southeast Boater said:

So the negative from the controller would be connected to one of the terminals on the bus bar on the right hand side? The left side goes off to the negative terminal on my battery bank  

Yes

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27 minutes ago, Southeast Boater said:

So I have returned home and I’m not entering sure where my shunt is. I gather I’m meant to wire the negative PV from the controller to the negative side of the shunt before it goes to the batteries and the positive PV from the controller to the shunt also before it goes to the batteries?

 

No. The positive doesn't go to the shunt, only the negative!

Edited by rusty69
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Your pictures suggest a well fitted set of electrics. The shunt seems to have only one cable at one of the ends which presumably goes to battery negative.

Your monitor seems to show your batteries are fairly full, so they won't draw much from the solar controller.

Are you sure there is something wrong?

Given that you don't seem to know much about electrics, and people here are suggesting things which you might interpret incorrectly, I would tend to leave well alone, and perhaps get an expert who knows how it all works to have a look. Said expert could be a paid electrician, or a boater who does a good deed.

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1 minute ago, Richard10002 said:

Given that you don't seem to know much about electrics, and people here are suggesting things which you might interpret incorrectly, I would tend to leave well alone, and perhaps get an expert who knows how it all works to have a look. Said expert could be a paid electrician, or a boater who does a good deed.

That sounds like good advice.

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11 minutes ago, Richard10002 said:

Your pictures suggest a well fitted set of electrics. The shunt seems to have only one cable at one of the ends which presumably goes to battery negative.

Your monitor seems to show your batteries are fairly full, so they won't draw much from the solar controller.

Are you sure there is something wrong?

Given that you don't seem to know much about electrics, and people here are suggesting things which you might interpret incorrectly, I would tend to leave well alone, and perhaps get an expert who knows how it all works to have a look. Said expert could be a paid electrician, or a boater who does a good deed.

In particular, you have the front cover of the Victron inverter removed. This has mains voltages inside and is definitely not a place to be poking around if you aren't very sure what you are doing.

Jen

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