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Forum Index : Solar : Looking for Low Cost Programable controller.
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| Davo99 Guru  Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I'm wanting to do a test/ play setup with some panels and a Charge controller. I have a PWM unit I bought years ago which is great but seems no longer sold. I have bought a couple of variations of the " Blue" designs and they are all equally worthless Crap with only pre programmed float voltages which are way too high. They will happily have a battery gassing off all day till there is no more gas, or power, to give. Does anyone know any decent, low cost controllers where you have the option to set the exact voltage's YOU want? |
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| Solar Mike Guru Joined: 08/02/2015 Location: New ZealandPosts: 1138 |
I have a couple of these PCM60X controllers running continuously for the past 3 years powering a 400AH 12V lithium battery. All charge set points are user configurable; have pulled one apart to see whats in it, very impressed, extremely well built and designed. Don't know about the PWM only products, many of the alcheapo's you see are complete crap, one good reason for making your own. Would stick with named brands there. Cheers Mike |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Not what I was looking for and much more than I wanted to spend for the Project but very helpful thank you. I have been seriously thinking of an off grid ? Hybrid inverter and I see the same company makes them too.... for not much more than these the competitors. I also see they mention there are fakes and knockoffs which I do now remember hearing about. [qUOTE]All charge set points are user configurable; have pulled one apart to see whats in it, very impressed, extremely well built and designed. Great to have a referral from someone who knows what's what and recommends something. I know what to go with now. If the chargers only are good It's a safe bet the other products will be as well. They are not that different in price to the knockoffs but at least I know now the quality will be decent. This will for the initial part be a play/ Learning setup and I have decided to wait on the inverter till I can find some suitable batteries first. I don't want a full fork pack yet, just something I can learn with and upscale later. Finding some batteries will be the trick, The inverter I can order any time. Don't need the best batteries, just something decent to run in limited capacity for a while. So many PWM are labelled MPPT but none of the online sellers give a crap about misrepresentation or honesty. As long as they get their commissions, all good. The controller I have been looking for I bought probably 7 years ago and ran it for 18 Months or so then ran it again maybe the last 9 Months just as a battery charger. Just connected up some batteries and a broken panel to stop them going bad. It's is programmable and just a good unit to use. I should have bought half a dozen of them. You are certainly correct about the Cheapies. In many ways they are worse than just direct connection. Add to that the very limited and outright lies of information supplied by the sellers whom wouldn't know their arse from their elbow and are also flogging things like useless kitchen gadgets and suspect ladies Unmentionables. The design of Controller I have may still be out there but in a different colour and packaging which I suspect but the lack of info about the things, other than pure and utter garbage, makes it impossible to tell. As for making my own, I Wish. Even as a kid was fascinated by electronics but could never really get my head around it nor had the stability in life to study anything. Not being too bright didn't help. :0) I was going to look at the victrons etc but the ones I have seen so far ( and more research needed) don't seem to be programmable either. I did have the idea last night during my insomnia that just putting a couple of 10A Diodes in series may get the battery voltage down enough for the cheapies I have by fooling the thing the voltage is where it wants them but not boiling the battery. Probably not going to be so easy but simple enough to give it a go. Thanks for your help, it will be very useful for a much more important purchase than this which I now feel a lot more confident in. |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
I had a few of those little 12/24v pwm's the last one (from new) boils batteries, can see it working properly with the solar input flashing, after a short time it stops flashing and dumps everything the solar panel has, into the battery. I agree its far better to have one with programmable voltage set points. Cheers Aaron Off The Grid |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135 |
It might be possible to modify the charger you have. Trace the circuit to find the feedback voltage divider. Then put a trim-pot and series resistor in parallel with the top leg of the divider. that will reduce the voltage. Experiment with values. I would start with 10 times the top leg resistance. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I bought one of those "make sky blue" controllers from e-bay a couple of years ago as a backup if my home brew unit ever spit the dummy. The 96v 30 amp unit I have, sells today for $145, there is also a 96v 60amp version for $175. For some reason the higher voltage units cost a lot more. The more popular lower voltage controllers for 48v and below are available from $80 up. These measure the battery voltage and automatically select the right voltage operating range, 12v 24v, 48v, etc so you cannot have a voltage accident when you first power it up. This is a true power point searching MPPT controller that definitely works to find the peak. On the 12v range (for example) the various bulk charge, absorb, and float voltages for three stage charging are all independently adjustable between 12v and 17v. Two selectable modes of operation, Lithium, and Lead Acid. It works fine, and IMHO pretty good value. Only one criticism, the case is built from very light gauge sheet aluminium, and as a heat sink at full rated power, I think its pretty piss poor. There is a thermostatically operated computer fan, and automatic over temperature shut down, but its really a band aid solution for cost cutting. The mosfets are held against the rear of the case which is flat. What I did was attach the whole aluminium box to a monster flat heat sink, and it now barely gets warm even flat out. I would have posted all this earlier, but could not find the original instruction sheet. Located that just now so I can be a bit more sure of my facts, my memory after a couple of years is a little hazy. They no longer advertise on e-bay, but now have a warehouse in Australia, so delivery should be pretty quick. https://makeskyblue.com/ Edited 2021-11-09 11:55 by Warpspeed Cheers, Tony. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I got some battery Charger Boards off Ebaligood which are for 240 chargers. They simply monitor the ( user programmed) battery voltage and turn the source ( battery charger) on and off. I haven't looked at them for a while but I have an idea they will run from 12V. A lot of them were Mechanical relay but I found some that ran mosfets so the constant on off isn't going to wear them out or more importantly make an incessant ticking noise. I wanted them for something else that they turned out not suitable for but they could be OK for this. Really would like to find a programmable proper unit like I have though. That thing has just been something that worked well and logically from day one and I have enjoyed playing with. Total and complete opposite to every other POS controller I have got which just don't work anything like the Chinglish instructions in universal language, Pictures, show. They are even cheaper and crappier than they describe. With the idea in mind of running loads more or less directly off what the panels are putting out, I'm thinking of a Direct connection so I'm not limited to the 30 A or whatever of the controller but say 100A ( panels allowing ) Direct. I'd run like a dual circuit setup with a Relay for the high side. When the voltage is closer to where I want it with the load removed/ reduced, this would drop out and the controller would charge at a proper level and then float the batteries. If the voltage dropped below the close set tolerance level, the high side would kick in again so there was little power drawn from the batteries. The load itself would be controlled but the load setting on the controller and disconnected if the voltage fell below the preset level as is a standard feature on these controllers..... although I sure as ship would not have it disengaging at 10 .8 or whatever a lot of the presets are.  |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I at least understand what you are saying there. Sounds very clever and workable. My ability to trace and work out what is what on the board is infinitely more questionable. :0( I didn't get to try the Diode hack today as I got involved with other things. One quick job I wanted to knock over went from one to another till they day was gone. I'll give it a go tomorrow as it's supposed to rain all day so that's something I can do under cover. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I have read of these before as well. This is a very good Heads up. Thank you Tony. Sounds very good and the adjustable voltage is what I want. I have quite a few big heat sinks I have liberated from GTI's I have scrapped. I could easy attach one of these likewise but with my proclivity for fan cooling whole inverter units with car radiator fans, may not be needed. I am surprised even with the big heat sinks how much heat is radiated through the entire unit. Conversely gives surface area when you have a fan that covers the entire area of the inverter.  I looked at the link and they have an impressive range of products and having a warehouse here seems a BIG Plus. Looking at their products Trigged the 2V light in my head and reminded me I have a latronics 2.5 GTI / battery inverter up the back. latronics Looking at that, this seems to run off a 96V battery system being Dual Mode. I could run it off a string of 8 12v Battery's. Can get 9Ah SLA's cheap enough to play with but for practical purposes a 96V Battery bank for a 2KW inverter would be a bit overkill. I have only seen one other latronics advertised since I bought this one a while back and of course the seller wanted stupid Money for the other one. I didn't really know what I was getting when I bought the one I have, as I remember it came with a bunch of panels I got. Looking it up they have a very good reputation and were made in Qld. They are very simple internally but have a nice big Torroid. The only thing with them is they run a pretty low string voltage on the PV side which mean a lot of series arrays when Over clocking them with 250W panels and even shorter strings with the newer, higher voltage panels. Would be nice to put this unit to use and would be a good emergency backup too. I could run it in solar direct mode with the little batteries but then if I need a charger, I may as well just buy one of the Direct inverters listed there and be done with it. Bit fuzzy ATM due to some new medication that's not working out well ( and it's only for Cholesterol not even my head!) But I'd probably on the 5th hand be better off with a Regular inverter/ charger which I could still play with little batteries and then up size later on. With the Latronics, I could maybe look at those Charger boards and use a Voltage Divider and make a bang bang controller with one of the 500V/ 500A relays I bought a while back or I might be able to get away with some Paralleled MOSFETS which would be better. I was looking at this inverter Batteryless Inverter which has inbuilt battery charging facility but I can't work out if it will work from batterys as well? That would be a great unit if it could and I'd probably go for something like that or the 4 KW version for the little extra money. They say grid tie but also can't work out if that is backfeed or just battery charging from the grid? Thanks again for the Link Tony. I have now got plenty of valueable info on equipment for the next and far more important step!  |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
I don't know many details on the 24v versions of these inverters but there was a 48v unit that would run without batteries, there are many clones about that may not work as well and may not have after sales service, but others have reported to be good. The genuine seller as far as I can tell are now in Sydney,off-grid-inverters They may have a bit better explanation on what's what, I only have an old 4048HS pwm (now known as HSE) and a 5048MS that has survived dead short on the output, still going well. I have had these working as just as charge controller, leave em turned off ans with the solar connected they will start charging at sunrise. Typically battery charging from grid or generator if no solar is available. Cheers Aaron Off The Grid |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Thanks for the info Aaron. I have a lot to think through with the next step up. I tried the Diode on the controller this morning, No Joy. The thing just hunts around from one extreme to the other. Acts the same as when the panel is attached but the battery is not. Hmmm, I wonder if a cap across the output and then take the Diode to the battery would work?? I spose when I think about it the thing probably can't get the feedback from the battery to sense the voltage but I thought it would have done it on it's own side. I also opened up the unit to see if there was maybe a trimmer or somewhere to put one. HA! It's all tiny, surface mount components that I couldn't identify let alone modify if my life depended on it. On the upside, I think I did find a seller that has the old controller I have. I'll have to message because there are 2 Different units shown in the one listing. If they are both user settable, no problem but the low lifes that infect fleabay and other sites so broadly cannot be trusted in any way shape or form. Neither can fleabay for that matter and my experience with the rest is not much better. See how I go. Appreciate all the feedback. It's been REALLY helpful. |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
A capacitor on the output to the battery can smooth the pulse a bit, most PWM's don't have any and just connect straight to the battery, not usually any problem on its own. The pulse noise can be disruptive to other equipment (connected to close to an inverter) but not so bad if connected directly to the battery terminal, just something to consider when connecting when connecting a setup. The MPPT units usually have a good set of caps inside. Most of these little pwm's have a Micro controller inside and a some standard program I suspect, and all SMD, still think there is some sort of voltage divider their somewhere that could possibly changed, not so easy to find though. Had a 48v version (no longer on sale anywhere) opened it up because the LCD had pulled out of the socket due to.......ROUGH shipping. Might get time to open one up one day and have a look. Good that you might have found a shop that may have the one you want, that would be easy. Personally I have always liked the user configurable stuff. Cheers Aaron Off The Grid |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
been looking at both the PIP and MSB inverters refereed. I like the idea of the standalone that can work with no batteries but have a few questions the knowledgeable might be able to fill in my difficulty in understanding what's on the site. I'm surprised I can't find anything on these inverters on YT. Bit on the charge controllers but nothing on these particular inverters. I have read of them before, maybe on a solar forum but can't think which one now. The inverter I am looking at specifically is This one. What I'm not sure about: Can it do true stand alone as in the middle of a paddock with some panels and provide 240V Power without batteries or does it have to be grid connected to do that? I thought it was true stand alone but something I read gave the impression that running without batteries might not have meant the true stand alone I thought and it may be without batteries but WITH grid to provide power? I take it this one does not do grid Feedback? If it does not do grid feedback, does this mean if I connected it to the grid it will power a connected load to the power it is producing but NOT send any excess to the grid? I think they call that " Zero Export?" That could be useful for an application I have. If it is true stand-alone and will produce power without Grid tie, that would be great in a grid down situation and as a backup and be justifiable before I go to batteries. If it will do grid export, so much the better. If it will do a zero feedback, I have a use for that too. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
It will need a battery always. The battery can be charged from solar, from a generator, or from the grid. Solar can charge at 60 amps. The inbuilt generator/grid charger is limited to ten amps. Its not exactly clear if this is a grid tie inverter, but I take it that its not. If you click on "download PDF manual there is more info, but its as clear as mud about grid tie. Cheers, Tony. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
That made me think. It clearly said no battery needed. Stupid me, I linked the wrong one sorry. This is the one I meant to link. Was looking at other ones trying to figure them out as well. That's not showing up on my browser. I assumed it wasn't there. Just tried it in Chrome instead of Firefox and I still can't see it or find a link even clicking around. I normally have no trouble with PDF's Just can't seem to get them off this site for whatever reason. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I don't much like the no battery requirement. Running off raw solar it will have zero extra surge capability and be hopeless with motors. It depends what loads you are planning to run I suppose. Cheers, Tony. |
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| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135 |
"I don't much like the no battery requirement. Running off raw solar it will have zero extra surge capability and be hopeless with motors. It depends what loads you are planning to run I suppose." Agree, even with non-surge loads when a cloud comes over it falls over unless panel array is vastly bigger than needed. Can it handle the voltage when lightly loaded in full sun? |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
Well with all the clones of these about the labelling system is a real dogs breakfast....to put it politely, the genuine ones where made in Taiwan and clones made in China, last I read about it, could have changed somewhat. So its difficult to interpret what they are advertising, From my understanding the type that will work without batteries must have the grid available to keep the power up when a cloud block's the solar etc. Some at this site AEVA know a bit about them, they are bit different crowd at times, there is a lot of stuff there so don't get lost trying to get through it all. The ones that feed back to the grid where usually Hybrids. The one in the link is probably just standalone and needs batteries to keep it going. There may be some proper manuals at the main site. https://www.mppsolar.com/v3/download/ Getting a headache looking at how much stuff is on the main site, they now do split phase 120 volt units. Its also best to keep the total pv voltage under the maximum rated voltage for these. Looking at the one in the link, some of the specifications seem to be a little off, could be they changed something, I will be back later to see how it compares with others. I did run a 4048HS unit off old truck batteries for years just for use during the day, worked fine. The MS units have the same Mppt charge controller built into them but upgraded from 60A to 80a. maximum 145VOC. The 450voc model, I will have to do a little more research on. Personally I prefer not to connect these to the grid in any way, the grid power in SE QLD and perhaps other places has a habit of blowing up all sorts of stuff, sort of reminds me of Windoze, keep it away from the internet and it works...  Edited 2021-11-14 19:06 by Revlac Cheers Aaron Off The Grid |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Both Tony and yourself make a good point. I overclock all my inverters and pretty much was a given I would this one too. I do like it because the input voltage is high enough that I could just unplug arrays that are used on my current GTI's and plug into one of these units with no problem. Over paneling in no way means over volting. I keep the voltages of the arrays in the sweet spot for the inverters and just parallel them. One inverter atm has 48 panels on it and only running 320V loaded but the solar input is over double the inverters wattage. The arrays are also split orientation so never really gets the full output not that it would matter but it does keep that inverter pegged even if it is slightly cloudy. I was down on one phase and over on the other so I just moved some of the array leads around so one inverter is producing max power as much as possible from sun up to sun down. Those "Y leads" are very handy for paralleling array outputs like that. The other phase is still getting more power than we use so I might have to get into the meter box again and move some of the circuits around to try balance things up. Was OK before but maybe we have changed out power use or something. Maybe running some marine/ automotive deep Cycle batteries might be a good idea to fill in the generation holes and add some stability. If I program the cutoff theshold high then they will be more like ballast than supply. I was really thinking of this for Critical loads like the refrigerators and freezer but they would also have some tolerance. Power draw is also pretty low so batteries to give some surge power and over panelling should be fine. I would also like to find a low cost Zero export inverter. The mainstream units are worth a fortune but I'd look at a cheaper knockoff if they were decent. Been looking everyday for a while for some decent low cost battery's but seems even the suspect ones are at least $1 ah in 12V and most even used are over $2 Ah. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
What I ran successfully for a very long time was a three phase dc rectifier that powered my inverter directly, along with some solar panels. Any surge currents always came from the rectifier, for example starting up my refrigerator. At night the rectifier provided all of the power. During daylight hours there was almost always enough solar to carry all of the load, but on dismal days, any shortfall came from the grid. No battery is required, and that is a major cost saving. In mid summer solar provided about 80% of the power, effectively dawn to dusk, extra panels would not have improved that. In winter solar provided about 55% which helped a lot with my electricity bills. More panels probably would not have helped all that much. When there is effectively zero solar, if I doubled up on panels, twice nothing is still nothing. The system slips smoothly from grid to solar and back again at dusk/dawn, and its all done with just a couple of diodes. No power can ever get back onto the grid, so even with a smart meter you are set to go. The inverter just draws power from the highest source voltage, its as simple as that. No solar controller required. The inverter has to be able to operate from a very wide input voltage range though, and that might be a problem with many common commercial inverters. But if you can match solar panel voltages to inverter input voltage, and find a big battery charger, that would be the way to do it. I believe you have three phase, so a suitably sized three phase fork lift battery charger would be the thing to look for. Provided all your voltages are compatible its the simplest and most economical way to stealthily reduce grid power, without going full blown grid tie. Cheers, Tony. |
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