Electrical SETECT ST-III and Battery Capacity

mikerezny

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Sep 11, 2016
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Hi,
I am sorry to differ, but be assured that the rated output on a panel is possible and is indeed easily exceeded.

I have a 40W panel rated at a maximum of 2.23A which can regularly output over 2.5A.
Panels are rated at a solar insolence of 1,000W per sq m. In Australia on very clear days solar insolence can easily exceed this figure and if this happens in the morning or in windy conditions which will keep the panel cool, current figures will exceed the panel specifications.

So, please change the word impossible to something which is actually accurate.

Failure to achieve the rated output is regularly caused by recovering batteries that are fully charged, panels not optimally aligned to the sun, or panels supplied by a dodgy supplier.
If I was buying panels, on delivery, I would set them up optimally in good sunshine ensuring they were not hot and measure the S/C current. If it did not provide the rated Isc, they would be returned as faulty.

take care
Mike
 

Boots in Action

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Mar 13, 2017
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Ferny Grove, Queensland
Am I reading it right that the MPPT controller you linked to only has a boost voltage of 14.4V? Or does it let you select AGM to get to 14.7V?
Hi @Fallen, it does not have a setting for AGM per sec, and as I wanted higher voltage than 14.4 volts for "sealed", I spoke to technical guy at Seller, and so selected "Flooded" which has a max charge rate (Boost) of 14.6 volts. Other specs such as Float (13.8 volts) , over voltage protection (16.5v), max charge limit (15.0v), over voltage re-connection (15.0v), and Boost restart 12.6v) are the same for all other type except GEL which has a lower Boost (max charge voltage) of 14.2 volts.
 

mikerezny

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Sep 11, 2016
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Unless they are fitted to a tracker it's all academic anyway as they will never be in optimum position.
Hi,
it is not difficult to set up a portable panel in an optimal position for an hour or so.
I usually need to go do something regularly enough that I can walk past the panel and give it a nudge often enough to keep it reasonably close to an optimal position.

I just want to dispel the myth that it is IMPOSSIBLE to get the rated output from ALL solar panels.
I very much doubt that panels supplied to solar farms do not meet or exceed specification.
Relying on this myth leads many inexperienced people to accept poor solar performance and to not attempt to investigate or understand what is causing it. The solution inevitably is just to go buy some more panels.

I suspect that this myth also underlies the reason for some dealers to quote unrealistic figures for solar panels knowing that:

1: A lot of buyers do not have the ability or understanding to evaluate the panel.
2: Buyers will generally accept an inferior product claiming that all panels are overrated anyway.
3: Those that are unhappy will more than likely whinge on social media about the *&^&*^*& panel but seldom sort it out with the supplier.

I was a retailer in electronics for long enough to understand how customers think and how marketing works.

take care
Mike
 
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Boots in Action

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Mar 13, 2017
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Ferny Grove, Queensland
Hi @Boots in Action, have just ordered an MPPT controller to replace the TPS 1230 in the van.
I have chosen the same one as you have as it seems to be value for the price and I don't see that blue tooth or other new fangled stuff is a
necessary requirement.
Will let you know how I get on.
@Johnanbev , I have been more than satisfied and it does all I need. You will have to connect the LOAD through the controller to get all the data. If you have any problems, let me know and I should be able to assist. Maybe have a look back to one of my posts on how that was done. @Grandpa Gunna has been successful at the modification I have on that post also.
 
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Boots in Action

Well-Known Member
Mar 13, 2017
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Ferny Grove, Queensland
Hi,
I am sorry to differ, but be assured that the rated output on a panel is possible and is indeed easily exceeded.

I have a 40W panel rated at a maximum of 2.23A which can regularly output over 2.5A.
Panels are rated at a solar insolence of 1,000W per sq m. In Australia on very clear days solar insolence can easily exceed this figure and if this happens in the morning or in windy conditions which will keep the panel cool, current figures will exceed the panel specifications.

So, please change the word impossible to something which is actually accurate.

Failure to achieve the rated output is regularly caused by recovering batteries that are fully charged, panels not optimally aligned to the sun, or panels supplied by a dodgy supplier.
If I was buying panels, on delivery, I would set them up optimally in good sunshine ensuring they were not hot and measure the S/C current. If it did not provide the rated Isc, they would be returned as faulty.

take care
Mike
Okay Mike @mikerezny , I have to bow to that comment and have changed the wording to "very rarely"- perhaps about as likely as me having perfect weather every time I am off grid.
Nevertheless, what you say does need to be considered and the makers of good controllers take this into account. The following is taken from the instruction booklet for my MPPT controller:
"This product has limited input power function, and in theory, no matter how much power of solar panel input, the controller will limit the input power
to under the rated power, but attention is drawn to the following.
As the Open Circuit Voltage of solar panel increases with decreasing temperatures, please ensure that the open circuit voltage will not exceed 100 volts as this will trigger protection circuits to prevent damage to controller."

And other place under features quotes as follows:
"PV array limited power input function to ensure controller does not overload operation under any conditions".

As the connection of my 3 panels only reaches approx 56.0 volts under ideal conditions, I do not believe i have anything to worry about.
 

Drover

Well-Known Member
Nov 7, 2013
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QLD
www.expandasdownunder.com
Hi,
it is not difficult to set up a portable panel in an optimal position for an hour or so.
I usually need to go do something regularly enough that I can walk past the panel and give it a nudge often enough to keep it reasonably close to an optimal position.

I just want to dispel the myth that it is IMPOSSIBLE to get the rated output from ALL solar panels.
I very much doubt that panels supplied to solar farms do not meet or exceed specification.
Relying on this myth leads many inexperienced people to accept poor solar performance and to not attempt to investigate or understand what is causing it. The solution inevitably is just to go buy some more panels.

I suspect that this myth also underlies the reason for some dealers to quote unrealistic figures for solar panels knowing that:

1: A lot of buyers do not have the ability or understanding to evaluate the panel.
2: Buyers will generally accept an inferior product claiming that all panels are overrated anyway.
3: Those that are unhappy will more than likely whinge on social media about the *&^&*^*& panel but seldom sort it out with the supplier.

I was a retailer in electronics for long enough to understand how customers think and how marketing works.

take care
Mike
Yep I do the same but my roof jobs take what comes......your points apply equally to van, car and many other purchases.
and we all know about salesmen............................. I have found this to explain things pretty well https://www.gorv.com.au/10-rv-solar-myths/
 
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Boots in Action

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Mar 13, 2017
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Hey Boots. The 30A reg you mentioned has a max panel output of 400w at 12v, how would you achieve the rated 30A with 400w of panels ???
More info for you @Crusty181. A max CONTROLLER output of advertised 30 AMPS at only 12 volts would amount to 360 watts . At a CHARGING voltage of 14.0 volts amps would be around 25 amps which is what I have achieved. As voltage rises because of less load, current would increase. However, the efficiency of a good MPPT controller is able to convert any excess voltage into more current within the limits of the design of the unit.
Note also, that all wattage produced , besides charging battery (if needed), also provides power for any accessories on at the time such as fans, radio, USB charging and any light that was necessary. And who knows if the 30 amp max could be achieved or surpassed. It is only a tested rating at the manufacturing stage.
 
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Boots in Action

Well-Known Member
Mar 13, 2017
1,527
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113
Ferny Grove, Queensland
Hi,
I am sorry to differ, but be assured that the rated output on a panel is possible and is indeed easily exceeded.

I have a 40W panel rated at a maximum of 2.23A which can regularly output over 2.5A.
Panels are rated at a solar insolence of 1,000W per sq m. In Australia on very clear days solar insolence can easily exceed this figure and if this happens in the morning or in windy conditions which will keep the panel cool, current figures will exceed the panel specifications.

So, please change the word impossible to something which is actually accurate.

Failure to achieve the rated output is regularly caused by recovering batteries that are fully charged, panels not optimally aligned to the sun, or panels supplied by a dodgy supplier.
If I was buying panels, on delivery, I would set them up optimally in good sunshine ensuring they were not hot and measure the S/C current. If it did not provide the rated Isc, they would be returned as faulty.

take care
Mike
@mikerezny , amended as requested with the relevant proviso though, See earlier post.
 
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Boots in Action

Well-Known Member
Mar 13, 2017
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113
Ferny Grove, Queensland
Hi @Fallen, it does not have a setting for AGM per sec, and as I wanted higher voltage than 14.4 volts for "sealed", I spoke to technical guy at Seller, and so selected "Flooded" which has a max charge rate (Boost) of 14.6 volts. Other specs such as Float (13.8 volts) , over voltage protection (16.5v), max charge limit (15.0v), over voltage re-connection (15.0v), and Boost restart 12.6v) are the same for all other type except GEL which has a lower Boost (max charge voltage) of 14.2 volts.
More info for you @Fallen . Yes AGMs do like around 14.7 volts (max) to achieve a full charge. Attached is copy of Battery type selection on the MPPT controller I have. So I selected FLD (Flooded type) to get voltage up closer to 14.7 volts. Remember, this setting is for battery temperature of 25C and the temp sensor will adjust this figure slightly as necessary - upwards when below 25C and slightly lower when battery temp is above 25C regardless of ambient temperature. Hence the importance of a sensor ON battery, not at controller itself. Hope this satisfies your query.
 

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