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Forum Index : Electronics : How to make an expensive MPPT unrepairable
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Murphy's friend Guru  Joined: 04/10/2019 Location: AustraliaPosts: 648 |
When I fitted extra solar panels on my caravan I knew the existing wire to the roof was too small, so an easy fix was to connect the 4 panels in series and use a MPPT controller with a higher solar input voltage. The one in a blue box was recommended and I bought a 150V solar to 24V/60A version. This worked very well until today when I checked the batteries (2 x 12v lithium in series), they were down to 12V - not good  .Disconnecting everything I found the MPPT was putting out only 12V instead of ~27V. Assuming some link inside had come adrift i tried to open it - bad mistake  . These things are designed to self destroy if one tries to open the case.   From the pictures one can see the choke wires in the lid have ripped out of the PCB. The only way they could have assembled this unit was to pour liquid resin into the cups in the blue lid and screw the thing together. Once the resin has set it cannot come apart without destroying it. I certainly would not recommend this brand to anybody. Having spent a working life repairing electrical/ electronic equipment and coming across something, which was rather expensive, made unrepairable really bugs me. I believe Poida also had a bad experience with that brand. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
That is crap but look on the bright side, it was obviously Cactus before you opened it. Is the resin such that you could melt it with a heat gun and replace the chokes or is it the proper chemically hardened type? Either they have a way of opening them or they just chuck and replace the things with no way to repair themselves.... which would indicate what their true value is worth and how cheaply they have them manufactured. I have read many less than glowing reports of this brand before. Seems another case that goes well against the old adage of getting what you pay for. More times than not these days, you pay a lot for cheap crap for something that relies on a brand name rather than lives up to past or advertised reputation. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Not a lot of ethics in business these days, unfortunately.... Cheers, Tony. |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Thanks for posting about this. I have three Victron MPPT controllers on my solar system. As I have three banks of different brands of panels I have split them. If a controller fails I will have to think seriously about buying any more of that brand. Like others here I like fixing my own things. I had a PowerJack inverter blow up twice recently, fortunately it is fairly easy to repair. I was considering replacing it with a Victron, but after seeing photos of the inside of them they look too complicated for what I want. Looks like I will keep repairing the PowerJack until I get around to replacing the boards with something like an 8010 board. They look simple and easy to repair. Not so many surface mount components, I am getting on a bit and the eyes are not what they used to be so surface mount stuff is not fun. Thanks for the heads up Pete |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
...and this is why I have helped develop home built mppt controller and inverters. I got 24 months out of the $2,700 Victron inverter. It failed on the 25th month, just out of warranty. Murph, use this to foster the anger and then that will produce more than enough energy to put into home built replacements. Which we can easily repair if needed. wronger than a phone book full of wrong phone numbers |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
That's For sure! Not a lot of quality either no matter how much you pay. |
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| Old Seagull Man Regular Member  Joined: 21/12/2019 Location: AustraliaPosts: 55 |
I wonder if the Chinese nock-off are any more repairable? As I have a bit of victron in the boat.Including a couple of the energy meter that have been quite good touch wood. And seeing that im far less likely to have an qualms about buying a clone of there product. I wonder if they make a reasonable copy of my old 60amp outback? |
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| poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
And by the way, the Victron mppt 150/70 retails for $850. Recently reduced from $912. plus GST. you can buy it here wronger than a phone book full of wrong phone numbers |
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mason Regular Member Joined: 07/11/2015 Location: CanadaPosts: 86 |
 Edited 2021-06-27 12:02 by mason |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Very few things are repairable these days, its a combination of surface mount, unmarked components, multilayer boards that are impossible to trace, microcontrollers with mystery firmware, and plastic enclosures/epoxy that require a certain amount of destruction to even get inside. And of course, no schematics or spares from the supplier. Another nice little trick is placing the main operating firmware in a battery powered ram. No charging of course, so that after a few years the battery dies, and of course whatever the program was goes with it. Cheers, Tony. |
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| Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
Yes this is on my list now. It will be a spare unit as an upcoming caravan trip forces me to buy another commercial MPPT controller. I need one with 100V solar voltage input and 40Amp charging, those can be had for under $200 trade price at Altronics... That expensive blue box was a lesson I'd rather not have learned. All my home build inverters can be easily repaired. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
Haha, welcome to my world guys. Only one I haven't seen (yet) was the last one with the battery powered ram ... all the rest are my bread and butter. Along with the openly 'anti' manufacturers who don't want me fixing their stuff ... though one did turn around early on and it felt like such a victory I was almost tempted to stick a copy of their cheques on the wall whenever I got one. I thought I'd won over another one a few years ago when they rang in a panic because something had gone wrong and blown up 40 or 50 boards ... but true to form, once I'd got them out of their pickle, they still refuse to help me. I realised they only came to me because they were going to look bad in the industry if word got out about the problem ... but once they were 'saved' they didn't need to be nice again. Doesn't bother me because I have a few friends in various spots around the world who are happy to share info freely and we look after each other well. Another issue with microcontrollers with mystery software ... it's clearly not practical with just one or two boards ... but if you need a few ... I know a place where we can get a micro copied for US$100 ... ... so send off a good micro along with the payment ... and in a couple weeks an email shows up with an attachment. Best one so far is an old PIC chip of which I have replaced several hundred now. A new board from the manufacturer is over $900 ... all for want of a $1.50 flashed micro. In the old days I would have felt guilty about copying a micro ... but when it means the difference between a new $900 board or a reasonable repair allowing a battler to stay in business ... I don't feel so bad. My aplologies for the bragging, but it's really to point out that despite the hurdles ... there are still ways to fix most things if we really want to ... there's just another level or two we have to get over. Cheers, Roger |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Not bragging at all and it's good to read you are helping others overcome the treachery of these ill intentioned companies and their purposefully shoddy built products. I realise I have a very different position and life experiences to most but I never and have not for a very long time, felt bad about fighting predatory, immoral or just plain mean behaviour with the same response. At the risk of offending those with Higher moral standards, ( which is probably most people) I think the position of "Not lowering oneself to the same standards" is the attitude of Victims and suckers. Trying to be the bigger man in cases like this is a strategy guaranteed to loose the battle every time. My position is fight fire with a goddam inferno so you not only win, but discourage the same bad behaviour again. When I'm on the side of right, Very few depths I won't sink to to scare a win over those that have ill intentions. I did a similar thing many years ago in my game. Some popular equipment required a Cable that was ridiculous over priced because of Proprietary plug that was anything but special, just designed to force people into buying their over priced Junk. and Junk it was. One thing to pay for quality that last for years and is dependable, but when you are paying for sub standard junk that even other Chines cheap equivalents left for dead, that' different. These leads were literally 40X what you could buy equivalents for. In a rare inspiration and frustration, one day I tore into one of these things and as suspected, they were nothing special at all. I got another connector, a washer and converted the equipment to take the standard leads that could virtually be bought on any corner store For $2, Literally. Took some pics, posted it on some relevant photo forums and within months people were doing it everywhere and reposting the into. It was the simplest, quickest conversion that any incompetent could do with ease and from what I saw, hundreds of people did. I have no doubt what so ever the info became so wide spread amongst users of that equipment which was the go to in the day, it must have killed sales of those overpriced leads dead. The other one I have no problem with is refilling printer ink cartridges. What Take that is! They work heard to create this misinformation and fear mongering that not using their over priced cartridges is not only going to stop your printer working, they create the impression it's going to detonate and take your home and loved ones with it. SO simple to refill these things and use them over and over. the ones I use are $25+ best price I have seen them. To refill costs literally under 3 Cents. I buy the ink in Liter bottles and get well over 100 Refils. At a $25 saving a Pop, easy to see what this is worth to me. I also do it or a few family and friends whom I put onto the right machines. Shed my dentist how to do it and gave him some ink after he complained how much it was costing him with his kids doing school assignments and got a lifetime supply of Syringes with blunt needles I use and gratitude that hasn't waned or failed to be mentioned in 3 years. The printer I am using now just passed 1000 A4 full colour pages. I expect it will Mysteriously shut down soon even though it's now working perfectly. They have a counter built in that keeps record of " Cleaning Cycles" and once the number is somewhere over 1000 Pages on the print counter in my experience is Reached, they stop in their tracks through a code the " Ink absorber pad needs changing." That requires total disassembly of the machine and a Jig to re assemble it which to the best of my knowledge and enquiry's, not even the approved service agents have even if it was remotely worth the labour cost of doing it. Something else to look after the environment with and reduce waste by throwing out perfectly good machines with who knows how much life left? Exactly what manufacturers don't want now days. Products that last. Sounds to me Roger like you are helping a lot of people and doing a public service and a very creditable one. The intention of the manufacturer was basically to sucker people and and feather their own nest at someone else's expense. They know dam well what they are doing and do it anyway so to me, all bets are off and if I can screw them over the same way they are trying to screw others, I'll not only do it, I will derive great satisfaction and enjoyment from it and share with as many others as I can how to so the same thing. Keep up the EXCELLENT work you are doing mate and feel duly proud of beating these greedy mongerals at their own game. |
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| noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 512 |
Lol, I had a similar experience.. A VERY expensive kubuto excavator my BIL owned died one day, with a faulty sensor on the boom... the replacement part was over 900 bucks !!!!! I just so happened to be there that particular day ( and he knows i dabble in electronics, lol got him off grid) so he hands me this gold plated diamond encrusted part ( insert sarcasm font ), which turned out to be a encapsulated potentiometer with 2 holes to mount on boom... I asked him what it does and he said it makes sure you dont " over reach " , but it never worked properly cause the hydrolic pump limiter would kick in long before this thing reported " too far " , so with a bit of thinking I ended up replacing it with a resistor devider ( literally 3 cents ) and never had a problem since... told him I could have replaced it properly, but he wasn't interested, said if you have half a brain you would never reach as far as this thing limited anyway even if the pump limiter allowed... But 900 bucks !!! It would be 50 cents at best for materials, how many poor sods have had to spend that ... I think it works !! |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
I don't know how many of those MPPT units shown above are likely to be around ... but it could be very handy for future reference if Murph could take some measurements. First thing I'd do is drill through the coil holes and out the back of the case ... then others could know the exact location to drill from outside in the future. How I would tackle one in future would be drill in through the case from behind the pcb ... at the four solder points for the inductors. Maybe a 8-10mm hole depending on the distance from case to pcb ... ... then unsolder the four legs ... and fight the lid off. I can see some transistors or mosfets in close proximity behind there as well ... but once you know where things are and have taken good notes and measurements ... it's amazing how accurate you can get. I first did some fully encapsulated boards about 40 years ago ... and after cutting a couple apart, discovered I could simply drill an 8mm hole, pick out the epoxy resin down to the board ... and resolder the dry joints on a particular electro. I did heaps back then and saved a lot of people a lot of money. There aren't that many different encapsulated boards that come in ... but there is one particular board that I have fixed hundreds of ... and they really don't take much longer than normal boards believe it or not. The first one I saw kinda got sacrificed and over time I fully denuded it ... and any time I have a tricky fault on one ... I get that one out to guide me as to where to dig and concentrate my efforts. Something I find amusing is that of the handful of techs I know around the world who fix this brand of equipment ... none of them will attempt this particular model. I keep egging them on and could get them a huge head start from where I started ... but somehow in their head, they believe they will be too hard to fix. Only last week I had a board arrive that I'd never seen before. I haven't fixed it yet, but Ive made good progress. Of course, as a one off it wouldn't make sense ... but there are thousands of these boards around and sooner or later there's likely to be a steady stream if I can make them work. The mess at the end of IC5 is the remains of a network resistor that I chipped ... so I temporarily stuck in some 0805 resistors on edge. I very rarely find any chips that have had their numbers removed, don't remember the last time ... it's really only micros that are programmed that are a worry ... but in the vast majority of cases they are still ok ... except for the ones I have already mentioned. Recently I had a couple of tractor column displays come in for repair ... I don't normally do that sort of gear, but they caught me at a weak moment. Apparently replacements are $5k ... and in both cases there were some 'beads' that were open cicuit and some were high resistance. Probably less than a dollars worth of parts to fix them both ... and they could have easily ended up in the trash.  Cheers, Roger |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
HA! They are all expensive! Mate and I have been looking for one for years and even the ones that are stuffed command a fortune! :0) Story reminds me of fuel pumps on cars. My Uncle years ago had his Camry Die on him. Got it towed to Dads wrecking yard which was close by. Bad fuel pump. New pump was $1400 from Repco or the stealers. I looked at it and said its a Commodore Pump. Changed a few of them in cars I had. I even know the designation, a Bosch 040. Fitted to about 100 Different Vehicles from Porches to Diesel 4WD's. $90 and the thing was fixed. Some years later mates Disco Land rover was stuttering up hills. Found the primary fuel Pump ( one in the tank, booster pump and the Injection pump) was bad. Pulled it out, another O40. Got that one even cheaper from fleabay in 3 days. Genuine pump cost.... $2500!!! Same as a headlight but the cheapest I could find for him with one of those was Still $1000 which I spose by comparison was a bargain. Found the same with Filters. Oil filter for my old Honda inline watercooled Twin mower was $84. Knowing how these things worked, I got online and looked up cross reference charts. Another common as dirt filter that fitted.... Subaru ... which I keep a supply in the shed and cost $13 genuine. Also Fits my Kubota Diesel tractor and is a trans filter for the Diesel ride on mower and Dads John Deere tractor. Don't even want to know what they are genuine.... Carb on Dads JD Mower got blocked, $500 New from JD and the same from Kawasaki whom made the engine. Found one on fleabay. Gaskets, fuel hose, filter, clamps, carb $34 inc postage. Works perfectly and has mixture adjustment which the original didn't have. Alternators are another thing. One unit fits 50 cars but one for one vehicle can be priced at $130 and the same alt for a different car can literally be $1000. At least with this stuff there is something to it in machining and manufacturing. Electronics can be so damn cheap and made for cents by the hundred thousand stamped out yet the markup..... Thousands of Percent! |
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| Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
This got me interested Davo. I just replaced my Canon printer because it started to make horrible clanking noises and refused to print. Cost of brand new printer and two included cartridges was $59.00. Now, a set of replacement cartridges costs easily that much so I wonder why they bother to have them replaceable in the first place? If it were not for the bother of setting this thing up (still have not been able to figure out the blue tooth print function  ) I'd go down this road but creating yet more electronic waste does bug me. |
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| Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
Good idea Roger but perhaps not easy with this MPPT. The inductors have 3 twisted wires (~1mm dia each) to connect to the PCB. The PCB is only 8mm above the heat sink so one would have to drill through the heat sink to get to the solder joints .I could tell you exactly where the centers of the two torodial chokes are so one could drill a pilot hole through the blue cover and then use a hole saw that cuts bigger than the choke diameter to free them from the lid. Sounds messy  .When looking at the PCB underside, where all the SMD components are fitted, I saw nothing obviously busted. I assume it was a program failure that suddenly failed to recognise I had a 24V battery connected and decided to charge it with 12V instead - which is what I measured at the battery terminals. Solar input was 80V BTW. This did no good to my expensive lithium battery but, fortunately, it charged up OK today with perhaps one of its nine lives lost. |
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Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
The internet is your friend with all this stuff. And this forum is pure gold when it comes to solar and inverter design. Rogerdw: this will be up your alley: link A 10 minute documentary on the battle of farmers trying to fix their giant expensive John Deere combine harvesters. The industry uses proprietary CAN bus messages that talk to a multitude of sensors and actuators. And the costs associated with maintenance after the warranty runs out is astronomical. So "hackers" are helping struggling farmers by reverse engineering the systems, or physically cutting out the smarts and replacing with simple on/off switches. I recently did battle with some error codes in the family car. The dealership was no help at all. The internet saved the day, but it took about 7 hours of reading various forums for the fix. Would have cost thousands if I took it to the dealership. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I saw this Vid when it first came out. I wonder How this went and if anything changed with it? I think a part of the problem at least is the Blind Paitriotism so many Americans have and their belief that anything NOT made in the US is crap and there is something wrong with owning it. Kubota make excellent tractors and in the Sub Compact to Medium market seem to be neck and neck with JD. Also lots of other brands like New Holland, Massey and even the knockoff Like Kioti all have good followings. I have a Kubota and My father has a JD and they are basically the same only different. They both have their advantages and drawbacks but overall I rate them Equal. In saying that though, some of their ways are quite backward and behind the times of the Japanese and Euro Tractors. One thing that does annoy me the JD is Typical American, The overdose of " Safety" features that impede what you are doing and create other safety problems if you are not careful and operate the equipment in a very specific way. Obviously the Japanese give people more faith and don't go overboard trying to save people from themselves. If some of these farmers were not so tunnel visioned with what they bought, they might do their cause some good. The thing I see is if they do get the right to repair, there are a dozen other ways JD can still screw them over and basically exact revenge and make the Revenue back. |
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