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Post Info TOPIC: Solar ???????


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Solar ???????


Hi guys new here and would like some help please .Ok here we go I have 300watts of solar panels on the roof of my van feeding 2x120amp agm batteries with a 30amp tps 1230 pwm controller that gets very hot to touch is this ok or should I purchase a new one with higher amps also what is a good brand to buy ???? Also is it ok to conect a seperate 200amp folding panel straight to the batteries with its own controller with the roof panels still connected or should they all run through one controller ??Thank you any help greatfully appreciated š

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Check that the wires going into solar controller are all tight as it seem like it may  be a loose or dirty connection 

Dragonfly1



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C Geyer


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Hello dickymate

I am not an Electrician

I have the same amount of solar, and the same amount of battery but a different controller/regulator/charger

There may be something wrong with your 30 amp PWM controller side of things if it is getting hot
If your controller is an el-cheapo $30 EBay one then the markings on the outside may not be what is inside
If your controller is a reputable $300 plus one then as dragonfly 1 has already said, it may be loose wires or dirty connection

My controller/regulator/charger is a CTEK DC/DC

I see something like 14 plus amps going from the solar to the battery and the controller is not warm
With the engine running the full 20 amps go to the battery and the controller is warm, but never hot

I believe that the consensus for us laymen, is that you should not have two regulators/controllers/ chargers, going to the same battery bank
Some techs say that it can be done

At the moment my system is suitable for my needs
I am thinking of a lightweight portable 200 watt, for the times I am under the shade, or not facing the sun

I have a thermal 30 amp re-settable fuse from the solar to the solar charger
My intention is to stop the roof solar going into battery, while the portable solar is connected either through the controller or direct to the batteries

Hope that this info is useful to you


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Tony

It cost nothing to be polite



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Hi

Solar reg getting hot hmm... probably not the best but u need to compare with same brand . My Mppt does not get hot but then again i dont touch the heat sink either . Not noticeable .Pumping 400watts into either single or dual 120ah . 195 fixed and 195 portable wired thru 1 x MPPT 30amp

Many people run 2 regulator setups . As u described there on board controller is maxed so they just buy a stand alone portable setup and connect straight to batts .
Not ideal but doable .

As mentioned all connections and existing wiring ccondition and sizing needs to be correct . The connectors in my panels were loose and done by a reputable company !!!!



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Is the compartment that it is mounted i well ventilated? That will have a big bearing on how hot it gets.

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PeterD
Nissan Navara D40 diesel auto, Spaceland pop-top
Retired radio and electronics technician.
NSW Central Coast.



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Hi Dick 

How hot is it getting ??

[1]Can you comfortably touch  it or put your hand on it.??

[2] is it open to cooling air  ,not contained in a cupboard or similar ?

 [3]  Definitely check connections for localised  heating



-- Edited by oldtrack123 on Sunday 6th of May 2018 05:51:02 PM

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My Mppt is under the bed near the battery I have only portable panels and being in a confined space it does not get hot at all,I would think that most regs would be inside there Rvs not outside in the air streams??...



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Ron-D wrote:

My Mppt is under the bed near the battery I have only portable panels and being in a confined space it does not get hot at all,I would think that most regs would be inside there Rvs not outside in the air streams??...


 I doubt that ANYONE is suggesting that the reg be outside the vanno



-- Edited by oldtrack123 on Monday 7th of May 2018 01:58:17 PM

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Outside cabinetry š

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Barboots wrote:

Outside cabinetry š


 Yes ,or where there is free air movement  to allow the  generated heat to escapebiggrin

All electrical equipment generates heat in use & requires adequate coolingsmile



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The bed has not gotten any warmer with the reg under it.biggrin



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Newbie

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Hi guys Thankyou for all your replies I checked connections like dragonfly1 said and seems to be ok now so far all good sorry for slow reply as our Nbn has been down again šš

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Hi dickymate, with an absolute max output of 20 amps from your 300w of solar there should not be any appreciable heat produced in a PWM controller because until it reaches the set voltage point it is just passing the current straight through to the battery. MPPT controllers do get hotter because of the inherent losses using electronics to change a high voltage @ low current to a low voltage @ high current, there is no such thing as a free lunch or electronics that don't converter some of the electrical energy into heat energy because they haven't made anything that is 100% efficient yet.

So, can you tell us the brand/nodel number of controller you have please?

T1 Terry

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T1 Terry wrote:

Hi dickymate, with an absolute max output of 20 amps from your 300w of solar there should not be any appreciable heat produced in a PWM controller because until it reaches the set voltage point it is just passing the current straight through to the battery. MPPT controllers do get hotter because of the inherent losses using electronics to change a high voltage @ low current to a low voltage @ high current, there is no such thing as a free lunch or electronics that don't converter some of the electrical energy into heat energy because they haven't made anything that is 100% efficient yet.

So, can you tell us the brand/nodel number of controller you have please?

T1 Terry


 So you are saying while passing current  it should not have any heat generated , but when not passing current it will heatnoconfuse

While conducting there is a small voltage drop across the regulator [easily measured]

Simple basic OHM's law Watts = V x Amps  , 0.5V x 20A = 10Watts

Yes , Mppt will get hotter due to extra electronics involved, so you have that right



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oldtrack123 wrote:
T1 Terry wrote:

Hi dickymate, with an absolute max output of 20 amps from your 300w of solar there should not be any appreciable heat produced in a PWM controller because until it reaches the set voltage point it is just passing the current straight through to the battery. MPPT controllers do get hotter because of the inherent losses using electronics to change a high voltage @ low current to a low voltage @ high current, there is no such thing as a free lunch or electronics that don't converter some of the electrical energy into heat energy because they haven't made anything that is 100% efficient yet.

So, can you tell us the brand/nodel number of controller you have please?

T1 Terry


 So you are saying while passing current  it should not have any heat generated , but when not passing current it will heatnoconfuse

While conducting there is a small voltage drop across the regulator [easily measured]

Simple basic OHM's law Watts = V x Amps  , 0.5V x 20A = 10Watts

Yes , Mppt will get hotter due to extra electronics involved, so you have that right


The PWM does generate a very small amount of heat, the better to quality the lower the heat generated. This does change when the unit goes into current control to stop over voltage charging damage because the Mosfet being turned on/off/on requires a diode across it to defuse any voltage spikes that would damage the Mosfet. Diodes do get hot when they are passing current and that needs to be dissipated via a piece of heatsink. The losses are still much smaller with a PWM controller so natural convection is enough the move the heat out of the heatsink and that is why the heat sink is much smaller for a PWM controller than for an MPPT controller and doesn't require a fan to stop it overheating.

This means if the PWM controller is getting hot while in bulk charging mode it is either current limiting because there is more coming in than the max current programmed into the controller, or, the Mosfet used is rather poor quality and has a serious voltage drop across it.

 

T1 Terry 



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dickymate wrote:

Hi guys Thankyou for all your replies I checked connections like dragonfly1 said and seems to be ok now so far all good sorry for slow reply as our Nbn has been down again šš





nbn down are you inferring that our 50 billion +++ dollar system doesn't work???

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T1 Terry wrote:
oldtrack123 wrote:
T1 Terry wrote:

Hi dickymate, with an absolute max output of 20 amps from your 300w of solar there should not be any appreciable heat produced in a PWM controller because until it reaches the set voltage point it is just passing the current straight through to the battery. MPPT controllers do get hotter because of the inherent losses using electronics to change a high voltage @ low current to a low voltage @ high current, there is no such thing as a free lunch or electronics that don't converter some of the electrical energy into heat energy because they haven't made anything that is 100% efficient yet.

So, can you tell us the brand/nodel number of controller you have please?

T1 Terry


 So you are saying while passing current  it should not have any heat generated , but when not passing current it will heatnoconfuse

While conducting there is a small voltage drop across the regulator [easily measured]

Simple basic OHM's law Watts = V x Amps  , 0.5V x 20A = 10Watts

Yes , Mppt will get hotter due to extra electronics involved, so you have that right


[a]

The PWM does generate a very small amount of heat, the better to quality the lower the heat generated. This does change when the unit goes into current control to stop over voltage charging damage because the Mosfet being turned on/off/on requires a diode across it to defuse any voltage spikes that would damage the Mosfet. Diodes do get hot when they are passing current and that needs to be dissipated via a piece of heatsink.

The losses are still much smaller with a PWM controller so natural convection is enough the move the heat out of the heatsink and that is why the heat sink is much smaller for a PWM controller than for an MPPT controller and doesn't require a fan to stop it overheating.

 [c]

This means if the PWM controller is getting hot while in bulk charging mode it is either current limiting because there is more coming in than the max current programmed into the controller, or, the Mosfet used is rather poor quality and has a serious voltage drop across it.

 Terry 


 Well one last go to try help you . 

[a]thing passing electrical current WILL develop heat , perhaps you have forgotten that simple fact  [OHM's LAW]: Watts = VxI 

 That law applies even with that mysterious stuff like extra low voltage DC.

When no current is flowing ,or  power being used within  unit there will be no heat generated.

IF a PWM is passing, say 20A & has say 0.5 volts drop within it [meaning the voltage on the input side is 0.5V  higher than on the output side]  there WILL be 10 WATTs of heat generated

If 50A with 0.5V drop will be 25W

That covers ALL the internal losses no matter where it is generated in the unit, [switching components   including MOSFETS ,SCR  transistor , diodes  what ever. ANY thing that has a voltage drop across it when passing current ]

The quality /amount of cooling surface   & surrounding ambient temp will determine  how hot it gets 

You seem to think the switching  generates  the heat in solid state switching ,IT DOES not ,unlike contacts which generate heat mainly due to arcing.

The diode   is there for the reason you say,but the heat generated in it would be minor  due to extremely small current it has to pass

Have you looked at the size of it ?

Yes ,the heat losses will be less in  PWM compared to a  similar rated MPPT ,which naturally must have more components carrying CURRENT.

Again using  OHMS laws,easy to work out

 

[c] no  IF it is a PWM ,[ PULSE WIDTH MODULATIONi ]t is simply switching the current on & off as determined by the SOC of the battery. It does not ,cannot alter the actual current value ,just the average [mean] value .

If a cheap one & have a amp meter in line you could even see those pulses  ON/ OFF ON /OFF

The better ones are faster & require a Scope to see the switching action.

And before you get carried away, they also have  stages,   but still with the PULSE WIDTH MODULATION of the current 

 Better quality may have an inductor  to smooth the OUTPUT  current, as all  quality MPPTS have



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Quote:

You seem to think the switching  generates  the heat in solid state switching ,IT DOES not ,unlike contacts which generate heat mainly due to arcing.

The diode   is there for the reason you say,but the heat generated in it would be minor  due to extremely small current it has to pass

 

Peter, best you don't advise or heaven forbid actually do any DC work involving solid state relays, if luck is with you it will just fail due to overheat but fires do happen. A few hrs practical experience will tell you a DC solid state relay gets much hotter when switching that it does simply passing the current through it.

 

T1 Terry



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Hi all I don't know if this will be helpful to any one but I just purchased 4 full river 150 amp Hour batteries from the automotive super store for a what I think was a good price $ 510.00 per battery buying 4 helped , their nominal price is the cheapest I had found $ 525.00 As I am new at this and will be hitting the road in August after 4 years building my motor home out of a Mercedes Benz lo812 bus we are so looking forward to our new way of life. This is the link to the super store
Cheers Stumpy. automotivesuperstore.com.au/

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Hi Stumpi 54 smile

I hope you are feeding those horses plenty of oats to pull those heavy batteries biggrinbiggrin Hope you enjoy your new way of life ??

Jaahn 



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Just curious 600 amp hrs of lead acid batteries what system of charger are you using stumpie .



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