Thanks Cupie for the link I just wanted to see a tec report on the subject that was well explained and this one seemed to be right on the money ,theres no doubt in my mind now that mppt is is in a league of its own...

Thanks Joe I see your using a pwm reg with your set up so obviously your happy with your reg,it would be interesting to see a report from a real techie on the subject,we have one here thats knowledgeable but he promotes pwm with his systems thats fair enough,but that goes against everything that I have read on the subject, it would be nice to hear from a techie that could give an unbiased slant on the Mppt reg ,I think from what I have read just about everywhere,most would use the more modern tec reg even on Rvs..

-- Edited by Ron-D on Tuesday 8th of May 2018 09:33:46 AM

Ron-D wrote:

---

Thanks Joe I see your using a pwm reg with your set up so obviously your happy with your reg,it would be interesting to see a report from a real techie on the subject,we have one here thats knowledgeable but he promotes pwm with his systems thats fair enough,but that goes against everything that I have read on the subject, it would be nice to hear from a techie that could give an unbiased slant on the Mppt reg ,I think from what I have read just about everywhere,most would use the more modern tec reg even on Rvs..

-- Edited by Ron-D on Tuesday 8th of May 2018 09:33:46 AM

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 On my previous van I had a tech based in Adelaide that fitted 300w solar to 2 x 120 amp AGM's and I asked him about MPPT controllers and his view was that I was my money I was spending but for my situation the PWM would be fine.

His statement was that while MPPT was great on large house type installations the PWM would be fine on my set up.

I went PWM and it worked fine.

edit; just to make it clear I didnt use T1 Terry because I didnt know of him at that time however I believe Terry is a "real tech" as is the guy that fitted my solar.

Phone around and ask some "real techs" and form your own opinion from there.

If you have made your mind up on MPPT then buy a good unit and go that way.

-- Edited by Dickodownunder on Tuesday 8th of May 2018 11:04:07 AM

T1 Has designed his system around Li batteries, [Almost constant voltage]& Panels who's PPP is low & leaves little power for a MPPT to make use of

A rather complicated way to explain it is that his panels & Li batteries are very close to being IMPEDANCE matched which means the system is operating @ max performance

Impedance matching of sources to loads does require some advanced technical knowledge, not something that many average electricians would understand & of course T1 is not an electrician.



If you could keep the LA batteries fully charged little will be gained by a MPPT.
But LAs are a totally different story, with the voltage dropping as they discharge.

The question one needs to ask themselves is .:

What is the best way to go ,

[a]Add more panels IF you have the space & weight allowance & use a PWM or  the extra cost of a quality  MPPT??

Of course IF  if you do not  have the roof space or weight allowance that option is out

HE is not comparing apples with apples!

Many of us have tried to explain that to him for a loooong time
A quality MPPT with suitable panels will ,overtime ,outperform a PWM. when used with LA batterries
The fact that every roof top solar system uses MPPTs is so they get the max available output from the panels

-- Edited by oldtrack123 on Saturday 12th of May 2018 05:25:41 PM

Good post oldtrack thats a very good explanation.

Cupie wrote:

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Ron-D wrote:

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Good post oldtrack thats a very good explanation.

---

 I agree  .. except that I had to re read it a few times before I got it,   ie LA means Lead Acid.  Then it all made sense.

"Impedance matching" ... gee that term takes me back 1/2 a century or so when I used to try to teach barely understood principles to very un-interested trainees/apprentices.  The only way that you could gain their attention was to say 'now this would make a good exam question'.  Up would come the heads & they would start scribbling furiously for a bit before nodding off again.  Unfortunately I too had been just like them & only learned enough to get the 60% pass mark so my knowledge was paper thin. Add to that is that my memory is piss poor.

  

---

 Hi Cupie 

You were a naughty boy  you should have worked harder 

I had a good start in  my tech life

My father was an Electrician & radio mechanic

From a very early age I use to sit & watch him doing radio repairs Asking questions all the time & even reading his Radio magazines & books

All stood me in good stead when I started  my electrical apprenticeship , got honours or credits in every exams

I knew a lot more  about electronics than any  of the electricians or more senior apprentices & by my third year was  doing ALL the company's service work on products they sold  & they sold just about every thing for engineering 

such as :

resistance welders With timers

Electronic flame failure devices

Photo electrical devices

Instrumentation of all type 

Westinghouse /Mc Kensie & Holland rectifying equipment   

Westinghouse /Rosebery  switchgear & motor control systems ,electrostatic air cleaners  & many other of their products 

Brown & Boveri instrumentation  & controls 

& that is only about half the list

 I also started doing an Electrical engineering  diploma course but after a few years had to give it up as I was on 24hr a day callout for the service work just could not handle it all & the company's Electrical Engineer & a director reckoned I was more a hands on person  [which was true] & that I had a job for life with the Co. 

That turned out to be true retired from them age 60Years ending up as a works manager

-- Edited by oldtrack123 on Sunday 13th of May 2018 12:59:58 PM

A few interesting bits in that video, the first bit @ 1.13mins shows a label from the back of a set of 3 panels that they sell. The specs are all STC ratings from a light box flicked on for a few secs and the panel temp at 25*C, yet a little further down the listing they show an NOCT of 47*C+/- 2*C so they are admitting the panel doesn't actually operate at 25*C yet they show no NOCT output readings, so you can take the outputs listed on the label with a grain of salt.
At around the 6 min mark it gets even more ridiculous, using their suspect figures the 100w panel will run at close enough to 100% efficiency. No MPPT manufacturer claims better than 80% panel efficiency, the 97% efficiency they spec is a cherry picked figure showing the difference between power in and power out, so they are really saying at the very best they are 3% inefficient or will waste 3% of anything that comes in .... and these are their very best figures, not the average or the worst, ya gotta wonder right there eh :lol:
The fact that no one in their right mind discharges their battery down to 11v regularly and the fact as soon as you start charging a battery it won't remain at 11v seems to be completely over looked.
A genuine video with 2 identical solar panels charging 2 identical batteries, one with a quality PWM controller and the other with a similar priced MPPT controller would show the reality rather than the nonsense, even swapping the batteries over between one and the other, then the solar panel between one and the other to clear up any doubts about one battery or panel being better than the other.
As far as using 24v or 36v panels to charge 12v batteries, why would anyone want to do that? You can't fit a grid tie solar array on the roof of a caravan that has a TV antenna, air con and a few vents fitted, so no point in pretending that you could buy them cheap and use them. Unless you can fit a decent array of large identical panels on your RV roof you can't connect them in series either, so no gain to be had with smaller cabling yet all the problems with high voltage feeding back into the panels and destroying them .... I have a few photos for those that don't believe it happens and I'd be happy to post them if anyone wants to see them.

T1 Terry

T1 Terry wrote:

---

oldtrack123 wrote:

---

T1 Has designed his system around Li batteries, [Almost constant voltage]& Panels who's PPP is low & leaves little power for a MPPT to make use of

A rather complicated way to explain it is that his panels & Li batteries are very close to being IMPEDANCE matched which means the system is operating @ max performance

Impedance matching of sources to loads does require some advanced technical knowledge, not something that many average electricians would understand & of course T1 is not an electrician.



If you could keep the LA batteries fully charged little will be gained by a MPPT.
But LAs are a totally different story, with the voltage dropping as they discharge.

The question one needs to ask themselves is .:

What is the best way to go ,

[a]Add more panels IF you have the space & weight allowance & use a PWM or  the extra cost of a quality  MPPT??

Of course IF  if you do not  have the roof space or weight allowance that option is out

HE is not comparing apples with apples!

Many of us have tried to explain that to him for a loooong time
A quality MPPT with suitable panels will ,overtime ,outperform a PWM. when used with LA batterries
The fact that every roof top solar system uses MPPTs is so they get the max available output from the panels

-- Edited by oldtrack123 on Saturday 12th of May 2018 05:25:41 PM

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 Really Peter? Are you sure you don't actually mean grid tied solar systems rather than all roof top solar systems? If you have 5kW or 10kW or 15kW of solar on your RV and feed it back into the grid rather than using it to recharge your batteries then listen to what Peter has to say. If you don't then ask to see Peters side by side actual real life testing that backs up what he is saying actually applies to RV size systems charging lead acid batteries.

T1 Terry is an Automotive Mechanical Engineer and part of that training involves extensive hands on knowledge involving the use of 12v and 24v battery systems. To get a 97% entrance exam pass into the Institute of Automotive Engineers and to hold that membership for over 20 yrs means you need to know a lot about DC voltage, wiring and batteries, very few licenced electricians would get a pass level in extra low voltage DC knowledge. That is where the problems seem to occur when an ex sparkie who spent most of his time in the office ties to apply what he thinks he knows to answer a question rather than applying knowledge he has gained actually testing his theories in a real life situation using the actual equipment used by the average RV owner. There is no value in using a controlled power supply as the input and a controlled load as the output to verify the value of any particular controller, you need to use actual solar panels and actual batteries to get genuine results.

 

T1 Terry

 

T1 Terry 

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 Oooh that nasty DC stuff , real electricians don't know about it ,but an auto mechanic does!! 

There is it is folks NO Real Electrical experience , No electronics knowledge  ,  but Lots of knowledge about those very complicated things called batterries even the nasty 24V  ones.  And low voltage solar panels

Not even an Auto electrician.

I wonder when Terry will accept  that the basic electrical principles applies to EXTRA low voltage DC & are the basics of every electrical apprentices first year apprentice ship .

THAT is how complicated it is .And why no license is required to work on it.!!!

 

Terry does not like theory for one simple reason it is beyond his understanding,  as many of us have seen with his posts here & elsewhere

 

Terry , I have given you the compliment  of having experimented with & developed  a system that is very suitable for use with LI batteries.,  in the van & motor home situation , but the red herrings are jumping every where ,trying to escape from your posts.

Lots of words do not indicate real knowledge but are  commonly called Bull S*#t, though  they may fool those who do not  know /understand the real facts 

For those who do not know , T1 interest in Lis & solar started about 5years ago from memory

.Compare that with some one who has spent a life time dealing with  all types of electrical equipment ranging from  Extra low voltage Dc & Ac up to thousands of volts Dc & AC

On two other forum , he demonstrated his lack of basic electrical theory  & simply could not accept he was ever wrong

Those Forums have some very qualified people on them,  but T1 took the same attitude there as he does  here ,

In the end he was removed from those forums.

Every one who does not agree with him is denigrated ,no matter what their qualifications. 

 

PS I am not sure where you get the idea that I spent most of my time in an office   that is total BULL S--t 

 But I will repeat the compliment I made previously

T1 has EXPERIMENTED & developed a system that is very suitable with LI batteries , much of that is due to the relatively constant output voltage of LI s over their working range, plus panels  whose MPPT point leaves little  power for a MPPT to convert .

No Magic , No voodoo  just very simple  basic electrical principles. [perhaps beyond a first year electrical apprentice  but certainly should be well understood by 3rd year

-- Edited by oldtrack123 on Sunday 20th of May 2018 07:39:20 PM

-- Edited by oldtrack123 on Sunday 20th of May 2018 07:53:06 PM

T1 Terry wrote:

---

Sadly Peter you don't know near as much as you think you do. An auto electrician is a part of being an Automotive Engineer, an Auto Electrician only gains a partial licence where an Automotive Engineer is tested and licensed in all aspects of the trade and must pass very stringent testing in all of the fields to gain a full membership into the Automotive Mechanical Engineers Institute, to get a 97% test result means you need to know and understand all the subjects.
Let's face it, if they train 1st yr sparkies in the extra low voltage field they all either forget what they learnt or weren't taught very well to start with. A sparkie considers 5% voltage drop to be well within the acceptable range, anyone who is skilled in extra low voltage work knows that is far from acceptable, yet the sparkie who wired you RV will argue till they go hoarse the wiring they used is adequate.

Peter, I don't dislike the theory side and I did gain high level passes in the Advanced Diploma in Electrical and Computing Technology and that does include a number of elements in the electronics field as well as AC & DC extra low voltage, low voltage, high voltage and 3 phase power. However, I do argue with those who rely on the theory side and don't test their theory to determine if they actually have the correct numbers in their equations, this will always result in an incorrect theoretical answer, garbage in will always result in garbage out.
Until the theoretical equations can verify your theories with actual test results using the actual equipment used by the RV owners you are try to look clever in front of, I will continue to call out your theoretical results as B/S because you simply do not understand the dynamics involved. That requires yrs of experience with extra low voltage work, not sitting in the office writing technical jargon for those who are really doing the work.

The problem you have Peter is to get any confirmation you ever actually worked hands on apart from during your apprenticeship you would have to disclose your real name and not the pseudonym you use on line. Anyone enquiring about your expertise using your real name may well find many who would not agree with your opinion of yourself or uphold your claim regarding actually working in the field in the disciplines you claim you have worked in.
On the other hand, I use my real name and my work is open for all to see and comment on both from the outside looking in and from actually using systems I have designed that can either confirm my skill level or deny what I'm putting forward as not working the way I claimed.

T1 Terry 

-- Edited by T1 Terry on Monday 21st of May 2018 04:09:02 PM

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Desperation now showing &  with lots of garbage

I'll let others on this & other forums determine the extent of my knowledge & skills [especially those  who have the qualifications to understand & decide]

But I will not  further debate on any subject with YOU,as it seems to be pretty useless!!!

-- Edited by oldtrack123 on Tuesday 22nd of May 2018 10:59:01 AM

T1 Terry wrote:

---

So you won't give your real name on this forum either Peter. For those that don't know, Peter gets real nasty when the people he is attacking start dropping bits of his real name into their replies. Seems Peter needs to hide behind a false name for some reason yet expects people to still trust that he knows all he babbles on about. Probably best to stay out of these type subjects until you actually have verifiable data to back up your theory talk, just because it looks good on paper doesn't mean the end results will match the hypothetical findings and to date you have never shown any actual photographic evidence of your experiments that back up you hypothetical chatter.


For those who enjoy a laugh, check out some of these videos www.youtube.com/channel/UC9v7v79mAlvKCrjrJvj-Fww where really smart people twist findings by other people into supporting their ad hoc hypothesis, the catapult baby is a good one as well as the alternate view on the handshake :lol:

T1 Terry

---

 Best be careful Terry " It seems Peter needs to hide behind a false name for some reason yet expects people to still trust that he knows all he babbles on about. ""  You are sinking pretty low now

And "Peter" is the name ALL my friends  & family call me, But my birth name & location are readily  seen on this forum  , so again you are starting to look like a desperate idiot

 

You use your real NAME ,NOW, ON this forum to advertise your business.!!!!

I  let others, who have a lot more knowledge & qualification than you ,to decide if I am just a theorist

But your true believers should start to have a good think about  what you really know. 

I doubt you could even past a 3rd year electrical  apprentice test 

They should also wonder why you no longer post on some similar forums 

You know the ones you were kicked OFF because of your attitude , when others tried to explain the real facts to you

My working life  was working on  probably the biggest range of electrical equipment than you could even imagine. 

Far from  spending my life sitting in an office doing paper work,  don't know where you got that from!!!

So I don't know  on what basis you keep posting that bu**"£t .

   

Oooh by the way that video is great

I,'m sure the babies name begins with a T

 

-- Edited by oldtrack123 on Tuesday 22nd of May 2018 11:19:59 PM

Glad someone is enjoying it, Peter doesn't seem to be :lol: Never mind, I doubt there was much more to add when the whole thread went south or what ever direction threads go when they loose their way, but if anyone wants me to explain something I've posted in clearer English I'm happy to do that if it helps clear up any foggy spots.

T1 Terry

Ron-D wrote:

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I dont think your enjoying this pee-ing comp either Terry  if your honest about it...but I am  ...

-- Edited by Ron-D on Wednesday 23rd of May 2018 04:57:41 PM

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I'm waiting for Peter to change direction and start digging up  I need some entertainment while on rest breaks trying to get all the aches to settle down so I can do a bit more so the on going battles with Peter are a great distraction ... and probably keeps Peter entertained as well.

Every so often a bit of valuable knowledge gets mixed up in these typing battles so it makes for good practice for all sorting the wheat from the chaff, as the knowledge base grows the chaff gets easier and easier to identify

 

T1 Terry 

-- Edited by T1 Terry on Wednesday 23rd of May 2018 05:09:14 PM

I think its harmless banter. John ,although I understand where your coming from ,look at the post count its been a very interesting debate  ,by two well educated guys that hnow each other well.theres not a lot of tec info but heaps of entertainment, just my view and I could be wrong...

-- Edited by Ron-D on Wednesday 23rd of May 2018 05:32:42 PM

Ron-D wrote:

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I think its harmless banter. John ,although I understand where your coming from ,look at the post count its been a very interesting debate  ,by two well educated guys that hnow each other well.theres not a lot of tec info but heaps of entertainment, just my view and I could be wrong...

-- Edited by Ron-D on Wednesday 23rd of May 2018 05:32:42 PM

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 Hi Ron 

Glad you see it that way  

But I think Terry will win out 

I'm loosing my stamina & concentration & loooong posts like Terry's are getting beyond me,

Too much having to read backwards & forwards & type correcting

Age is starting to take it's toll, but still cannot complain too much with 90th birth day coming up this year