Advice on solar.

BIGWESTY · Veteran Member

Advice on solar.

Whenarewethere · Guru

Is it a 24 volt panel as 8.8 amps is about half what it would be if is was for a 12 volt setup. I get 3.9 amps from my panels, 6 x 20 watts (2 panels in series x 3 sets) or in other words 7.8 amps if the 120 watts were all in parallel. If you have a MPPT controller you should be ok.

-- Edited by Whenarewethere on Saturday 20th of April 2019 04:49:54 PM

Peter_n_Margaret · Guru

What is the solar controller make and model?
What is the solar panel voltage?
Read the instructions.
For most controllers it is necessary to connect the batteries first, so it knows what the system voltage is.
Then connect the panels.
Cheers,
Peter

BIGWESTY · Veteran Member

thank you.

Peter_n_Margaret · Guru

BIGWESTY wrote:
thank you.

If you actually want some assistance, it would be a good idea to answer the basic questions asked.

Cheers,

Peter

BIGWESTY · Veteran Member

I got the assistance I asked for (from you) and I thanked you , what more do you need.

T1 Terry · Guru

BIGWESTY wrote:
I got the assistance I asked for (from you) and I thanked you , what more do you need.

:lol: It can be a bit like that here, they want to gloat in your mistakes or something.

I think Peter has nailed it though, the panel voltage is too high for the controller to handle. By connecting the battery first, it can switch the panel straight through to the battery and that will hold the voltage down close to battery voltage. The problem will arise when the battery reaches closer to the upper charged voltage level. At this point the controller will start turning the panel off/on/off/on in an attempt to control the voltage at the battery. If the off is long enough for the panel to reach its full open circuit voltage, this is likely to be higher than the controller is designed to handle, so the over voltage error will trip again.

The fix would be to either find a controller that can handle the open circuit voltage of the panel, or a panel with a lower open circuit voltage that is within the range of the controller.

T1 Terry

Jaahn · Guru

Hi Bigwesty smile

I do not believe Peter wanted to gloat in your mistakes or anything like that. In fact perhaps he, like myself and Whenarewethere all think that you have a panel which might be badly matched to a 12V battery with a PWM regulator. But seeing it is too difficult to give the information we will not bother any more. Terry might have said that a MPPT regulator would do the job Ok but he refuses to.

Perhaps you have a 24V battery so it is OK. Forget my suggestions.

Cheers Jaahn

-- Edited by Jaahn on Wednesday 24th of April 2019 08:19:00 AM

T1 Terry · Guru

Did you have a bad Easter Jaahn, no easter eggs or something? The last line of my posts mentions either a regulator/controller that can handle the open circuit voltage, or a panel that is within the voltage limits of the controller/regulator.
You seem to give a lot of credit to all MPPT controllers that they don't deserve, a lot can't handle more than 28v for charging a 12v battery, this includes the CTek dual DC to DC and solar MPPT controller, I think its limit is 23v.
Perhaps a bit of caution with the gung-ho MPPT recommendations, maybe specific makes and models might save members running off and buying the wrong piece of equipment.

T1 Terry

Jaahn · Guru

Hmmm cry

Perhaps I should put in a Disclaimer Terry confuse

While Jaahn makes every effort to ensure that things he says on this site are accurate to the best of his knowledge, such material does in no way constitute the provision of professional advice. Jaahn does not guarantee, and accepts no legal liability whatsoever arising from or connected to, the accuracy, reliability, currency or completeness of any material contained on this website or any linked site. Users should seek appropriate independent professional advice prior to relying on, or entering into any commitment based on material published here by Jaahn or indeed anyone else, which material is purely published for reference purposes alone. You should read any and all instructions and specifications of all equipment that you use to establish they are suitable for the use you intend for them.

Cheers Jaahn

-- Edited by Jaahn on Wednesday 24th of April 2019 04:07:50 PM

T1 Terry · Guru

I wonder if I can abbreviate that enough to fit in my signature line Jaahn. if I just added it to each post I'd be in trouble for long posts.
Probably easier not to attack if you want to avoid any retaliation .......

T1 Terry

Extraordinary Rendition · Veteran Member

I know all of this can be very confusing. Anyone who requires thier technical systems to be functionally optimum only need aquaint themselves with some very straight forward Electrical Engineering. If you were to devote 40 hours of study to this topic you would be completely across all of the Physics. It would save you many hundreds of hours of asking "experts" to break it all down for you. Even if the experts are trying thier very best to give you sound advice your lack of basic knowledge might mean that a paucity in communication leads to you misinterpreting the Expert advice at first remove. Best way to fix the whole clusterf¥£ is to take a short time to learn the basics. It is interesting and fun. Lots of great scientists and history . Faraday. Ohm. And you will emerge from your studies a master in your own life.

T1 Terry · Guru

One of the most common misunderstandings I have come across at this yrs Stone The Crows, is that solar panels are not like and other power source. Where a battery charger has difficulty getting the current it has available through undersized wiring, the output voltage will increase. This doesn't happen with solar panels, unless there is a clear path for the current to flow to the battery, it just doesn't put any current out past a certain voltage.
When we explained about measuring the voltage at the output of the solar panel and comparing it to the battery voltage while the it should be charging and the max difference should be 1v if a PWM controller was used, they had difficulty understanding that measuring the voltage at the input side of the solar controller would give exactly the same readings ....

T1 Terry

Extraordinary Rendition · Veteran Member

T1 Terry... oh dont you just find it such a bore! ... these common misconceptions.. best way to deal with this is to explain to the flock how to visualise an electron. Not one in the city you understand. In the realms of free camping a proper Australian outback electron. Actually I required an electron in Tennant Creek whilst roughing it. I still have that electron in my off grid habitat. I don't find that the Cheap and Cheerfull electrons I have purchased off flea bay perform as well as the electrons that have been pontificated over by grey beards with an immense breadth and depth of experience. I am on the lookout for a replenishment of my supply of electrons. But I am not sure how many to acquire. Is there some White Knight expert that can recommend a supplier of reliable electrons? How many do I need to get back to where I need to be? I am told by my wife's boyfriend that about 2.7 E56 would be a bare minimum and he knows where an only slightly used electron can be got for .00001 of a Vietnamese Dollar. Is this a good deal?

Jaahn · Guru

Extraordinary Rendition wrote:
T1 Terry... oh dont you just find it such a bore! ... these common misconceptions.. best way to deal with this is to explain to the flock how to visualise an electron. Not one in the city you understand. In the realms of free camping a proper Australian outback electron. Actually I required an electron in Tennant Creek whilst roughing it. I still have that electron in my off grid habitat. I don't find that the Cheap and Cheerfull electrons I have purchased off flea bay perform as well as the electrons that have been pontificated over by grey beards with an immense breadth and depth of experience. I am on the lookout for a replenishment of my supply of electrons. But I am not sure how many to acquire. Is there some White Knight expert that can recommend a supplier of reliable electrons? How many do I need to get back to where I need to be? I am told by my wife's boyfriend that about 2.7 E56 would be a bare minimum and he knows where an only slightly used electron can be got for .00001 of a Vietnamese Dollar. Is this a good deal?

Hi Hanna smile

Perhaps I could give you some of my disclaimer to put on your posts. Just put your name in the boxes.

{ _______ } does not guarantee, and accepts no legal liability whatsoever arising from or connected to, the accuracy, reliability, currency or completeness of any material contained on this website. Users should seek appropriate independent professional advice prior to relying on, or entering into any commitment based on material published here by { ________ } which material is purely published for { ????? } purposes alone.

Jaahn

oldtrack123 · Guru

T1 Terry wrote:
One of the most common misunderstandings I have come across at this yrs Stone The Crows, is that solar panels are not like and other power source. Where a battery charger has difficulty getting the current it has available through undersized wiring, the output voltage will increase. This doesn't happen with solar panels, unless there is a clear path for the current to flow to the battery, it just doesn't put any current out past a certain voltage.
When we explained about measuring the voltage at the output of the solar panel and comparing it to the battery voltage while the it should be charging and the max difference should be 1v if a PWM controller was used, they had difficulty understanding that measuring the voltage at the input side of the solar controller would give exactly the same readings ....

T1 Terry

The electrical theory according to T1 confuse

Now explain the different types of power sources.

Constant potential,

Constant current

& all the variations in between

Including one where the voltage actually rises as the current increases

-- Edited by oldtrack123 on Sunday 28th of April 2019 08:53:52 PM

denmonkey · Senior Member