 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Solar : Australian Standards and DIY solar install
  Page 4 of 5   |
|||||
| Author | Message | ||||
InPhase Senior Member  Joined: 15/12/2020 Location: United StatesPosts: 178 |
Yeah. I was thinking like one or two good thumps a day would probably be OK. |
||||
| Warpspeed Guru  Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I didn't either. I still have no idea what the Guest Book actually is or how to go there. Must be some kind of secret occult place only initiates know about. Looked everywhere for Pete's post could not find it. Did a search and I ended up in the Guest Book, wherever that is. Its very odd. There are five pages of threads that have been started there, most with zero replies and a huge number of reads. Its like entering "The Twilight Zone". https://www.thebackshed.com/forum/ViewForum.php?FID=1 Edited 2021-11-05 08:18 by Warpspeed Cheers, Tony. |
||||
| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 457 |
I don't know how my post went into the Guest book. I logged in and clicked New topic. I will have to check next time as it obviously is harder to get answer if no one can see the post. Thanks for finding my post and the suggestions, all is good now. Pete |
||||
| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Maybe its necessary to first enter one of the sub Forums before you hit "new topic". If you just hit new topic first, the guest book may be a default destination that sends you to never never land. Just a theory, I have not tried it. Cheers, Tony. |
||||
| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Yes that is it ! If you go to the Home Page and hit "new topic" it sends you to the Guest Book and your post ends up there where nobody can see it. A bit of a trap. Cheers, Tony. |
||||
| Jacob89 Newbie  Joined: 10/09/2017 Location: AustraliaPosts: 39 |
I'm going to have to bite and take you to task on a couple of these points Davo. I guess you can say I'm on the bandwagon because I recently imported some Lifepo4 cells and built myself a 14kwh bank. I would have needed at 800ah of lead acid to get the same usable capacity (if I didn't want to take them below 75% SOC). But all other considerations aside, lead acid was not a option for my use case anyway due to the size and weight. But I did price new lead acid batteries a while back and with the exception of used forklift packs I couldn't any new lead acid options that could compete with my lifepo4 on price. About $3500 for 14kwh usable capacity. Now, on paper the predicted life span is very good. Supposedly they're meant to be good for 3000 cycles to 100% DOD and still have 80% usable capacity after that. Of course that remains to be seen, maybe I'll have egg on my face in year or two. Lifep04 is at a stage where its just starting to gain widespread use. It just hasn't been around long enough or used widely enough to be able to make a really accurate judgment on their longevity. But I'm hopeful. In my case, they'll rarely see much more than 50% DOD so in theory, they should last even longer. Once again, it remains to be seen. One thing I really like about them is that they can sit partially discharged for extended periods without harm. In fact, its better for them that way. In extended cloudy periods they can suck up whatever little the solar can give and if they don't get about 60 or 70% SOC for a week it doesn't matter. Usually I can easily cut my usage back so its rare that I need to use grid power(I have that available for now, will change soon though). I don't need to worry about getting the voltage up every day to prevent sulphating. The only occasions I'm aware of where anyone got a decent lifespan (10+ years) from lead acid in an offgrid scenario, the bank was substantially oversized so they never went below 80% SOC and a generator was run every time it was cloudy to make sure they came up to float voltage every day. As for the price not going down any more, well I really don't know if it will or not, but they certainly have gotten substantially cheaper over the last 5 or 10 years. Lithium production is ramping up, and Lifepo4 doesn't contain the rarer, more expensive elements (cobalt, nickel, manganese etc) that other lithium chemistries rely on. Which I think bodes well for it. And I'm no economist, but I really don't think its as simple as increased demand = increased price. I think the demand has really on increased because the price has decreased. As in, there is a massive demand for cheaper batteries. There is not much demand for very expensive batteries. I think we saw something similar with PV. Back when PV cost north of $10 a watt, demand was much lower. I have an old Jaycar catalogue here from 2006, an 80w panel is priced at $900. And that's 2006 dollars as well. Who the hell could afford it, at that price? Of course, I am aware that that making PV much cheaper was obviously easier that reducing the cost of batteries. I'd be interested to know what prices you guys are paying for the forklift packs. If they are cheap enough, well than the shortcomings just don't matter as much. I still can't make use of one myself due to the size/weight (tiny house on a trailer) but I wouldn't mind one to build a cheap offgrid system for my folks. |
||||
Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1021 |
I'm glad you said partly discharged instead of partially charged state (had to read it twice to be sure) Lithium is usually shipped with a low SOC and should be charged asap left flat seems to stuff them up, also they don't like long slow trickle charge, bought a 12v FLA once, found it to be 9v when checked, was promptly returned to the shop for a replacement. I saw a set of 16 Lipo4 320Ah the other day, for $825 and $25 shipping plus tax on all that, To be honest they could send you a box of concrete and get away with it, be warned. As for a big forklift pack, I think they should be fine for most people without the need to shake them up, some big motor starts and running a kettle and charging should keep them stirred enough, used to see tiny bubbles in the clear case Exide cells when charging. Cheers Aaron Off The Grid |
||||
| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I bought thirty 60Ah Winstons (6Kwh) about four years ago, installed cost about $3,600. Yes they are very efficient with excellent characteristics and twenty seven of them show no sign of any degradation. BUT three cells have failed totally and suddenly dead short circuit over three years. That has been a very expensive battery, just the cell failures have cost me about the same as if I had never left the grid. I have an excellent cell monitoring and balancing system, the battery has never been abused in any way. I am not the only member of this Forum that has had identical sudden cell failures. At that rate of failure an estimated cost of $360 per year. Delivery cost for one cell only just about doubles the cost. The whole system does not save me that much in grid usage. Now for about the same money I could have bought a 500-600Ah fully refurbished fork lift battery with a five year warranty that would have had at least five times the capacity at the low discharge rates I am running. Replacement individual cells are far cheaper as well. I would definitely recommend Lipo for things like boats, camper vans and electric vehicles where size and weight are critical factors that outweigh anything else. If you are off grid and you have a big shed out the back where a huge 1100 Kg lead battery is no problem, that would be the way to go. There is no "best" it all depends on your application. But bang for your buck, I totally agree with Dave that for storage capacity and return on investment, lead still has a lot going for it. Edited 2021-11-05 12:36 by Warpspeed Cheers, Tony. |
||||
| Jacob89 Newbie Joined: 10/09/2017 Location: AustraliaPosts: 39 |
Isn't partially discharged/ partially charged more or less the same thing, depending on your perspective? Glass half full/half empty type of thing. In any case as far as I understand it would be have to a very low SOC to be harmful. From what I've read about 50% SOC is idea for long term storage. This does make them less than ideal if you wanted to use them in backup/ups kind of situation. Not great for them to sit around at 100% all the time. You do have be very careful, especially if you're ordering off aliexpress. Scammers abound there, anything that seems too good to be true will be, they won't even bother sending you a box concrete, you'll just get nothing. I went with a seller on alibaba that I found had a good reputation on another forum and even offered a (small) discount if you mentioned you'd discovered them on said forum. |
||||
| Jacob89 Newbie Joined: 10/09/2017 Location: AustraliaPosts: 39 |
I do remember reading this and it is disappointing. I wish we knew exactly why they failed. I don't think a failure rate of 10% is standard, at least I hope not. I'm hopeful that I won't have the same experience, but who knows. |
||||
| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1021 |
Also it should be said that battery technology (of any chemistry) quality can vary widely for any of these, even from the same manufacturer. 50% SOC sounds good, some have been a lot lower (perhaps 15%) when shipped, apparently people put them into service with out a charge up and expected it work out of the box, failed miserably. Currently Trying out a set of Gangfeng batteries, charge to 100% then charger cuts out, uses power from the battery to about 98% SOC, the rest of the day everything is run completely from solar, the occasional motor start takes a small surge from the battery, time will tell how long they last. Cheers Aaron Off The Grid |
||||
| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I never replaced those three cells, the system still runs with only 27 cells but I have had to turn down the inverter to 220v. I am off grid right now, but it would not work like this through mid winter. I hope to get a couple of fork lift batteries after the Christmas break, maybe mid February. The other poster here that has had identical cell failures asked the Australian supplier of his Winston cells about these failures. The reply was that he had NEVER ever even heard of such a thing. Yet I have had three identical cell failures myself. Apparently its due to dendrite formation. Sharp crystalline spikes grow and short out a cell. The voltage drops to zero with slight cell swelling. There is no information that I can find about what causes this. The most worrying feature of all is the suppliers denial that the problem even exists. Once the voltage drops below 2.0 volts, permanent cell damage occurs, and blasting away the short does not lead to cell recovery. Also cell voltages over 4.0 volts lead to permanent damage too. I have never come anywhere near that. So one little voltage mishap can cost you very dearly by destroying a battery worth thousands. I thought being paranoid with all my multi layered individual cell voltage protection, would prevent any cell damage, but not so. Its been a very expensive lesson. Cheers, Tony. |
||||
| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 457 |
I went with VRLA batteries because I wanted proven technology. I know that Lithium cells have great characteristics on paper but having had devices that use them such as Laptops, I have not had a good run with them. They have not lasted anything like the paperwork s ( ays. So Lead Acid was the way I went. I did notice quite big dips in voltage when trying to start my compressor, and wood splitter. I have a 24 volt system and a 1500 watt air compressor ran but struggled a bit to start. My solution was to add a 500 Farad capacitor bank in parallel with the batteries. Now things just fire up straight away, no struggles. This is the best setup I have had, and I have had solar power ( stand alone) now for nearly 40 years. Systems have grown over the years but then prices have dived enormously. When I first looked at solar panels a 20 watt (X20) panel was $350, that was in the late 1970s. A bit out of my reach at first. Pete |
||||
| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1021 |
I have not had a good run with lithium cells in laptops either, have used the laptop on batteries about a dozen times from new for no more than half an hour and they are not holding up well at all. I have a load of used 18650 cells that where thrown out, joined them all up and have been running the house with them for years, the youngest cell is built 2012, so why are they so pathetic in a laptop? Cheers Aaron Off The Grid |
||||
| Jacob89 Newbie Joined: 10/09/2017 Location: AustraliaPosts: 39 |
Did you actually have a voltage mishap, that you know about? Since you've gone to some length to protect against such things, and the other 27 cells seem to be doing ok, that seems unlikely. It strikes me as more of a manufacturing defect, perhaps a bad batch of cells? I don't really know much about winston cells but I what I had heard was always positive. I have EVE cells, and I've not heard of cells failing as a short circuit like that. I know some people have ended up dodgy used cells from Aliexpress, that have been abused and are all swollen up due to overcharging. But they do still seem to work and provide useful capacity, although usually not the capacity that was paid for. Apparently there's a glut of used and abused cells from all the electric buses and other vehicles in chinese cities, that get re packaged and flogged off as new by disreputable sellers. |
||||
| Jacob89 Newbie Joined: 10/09/2017 Location: AustraliaPosts: 39 |
Keep in mind though that the Lithium Ion cells used in laptops, mobile phones and other consumer electronics are not the same chemistry as Lithium Iron Phosphate (Lifepo4) commonly used for offgrid. Lifepo4 has a much higher cycle rating than lithium ion. Laptops are probably fairly harsh on batteries, too. They're often quite hot, which is bad, and if you use it plugged in most of the time, the batteries are kept fully charged for extended periods, which is also bad. I think a lot of laptop batteries are just under sized for the task as well. |
||||
| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1021 |
@Jacob89 Yes I think that would account for most of it, the phone battery charges to 4.3v the laptop ones I don't know what voltage they are getting to inside, but always subjected to a lot of heat, we are supposed to buy new laptops and phones all the time and replace batteries, much like everything else these days. Been thinking about this silly fixed batteries unlicensed work limited to 1Kwh, probably come up with some cleaver disguise, in future they are likely to come in and check the battery capacity, there might be a nice neat battery storage box with something like 4 lawnmower size batteries inside, if asked "how do you run the house with that?" Answer....everything is turned off at knight.....little they need to know.  Then later on, reconnect the others that are hidden out of sight,  Just thinking...the batteries (with solar charger) that start the genset are bigger than 1kwh capacity, so are many other installations that people would use, more of an auto electrical installation rather than a solar installation.....or are they going to cross that line at some stage. Edited 2021-11-05 19:31 by Revlac Cheers Aaron Off The Grid |
||||
| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
No perfectly normal operation one day, the next day zero volts across one of the cells. I mean truly zero, not even 0.1mV measurable. This is an old picture from Jan 2019 showing how I monitor the voltage of each of the 30 cells continuously. Upper and lower readings are the max and min voltages ever reached. Middle trace is real time cell voltage.  One day perfect, next day middle and lower traces of one cell completely gone, right off the bottom of screen. The cell just spontaneously shorted out. The other Forum member that has had this shorted cell problem is using much larger Winston cells. So its definitely not limited to one cell size or one batch. Edited 2021-11-05 19:45 by Warpspeed Cheers, Tony. |
||||
| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Sorry but to me this makes no sense. It's like saying I bought a V8 Supercharged engine because I didn't want to take it over 1500 rpm. Even then your maths is still a long way out because 800Ah would be roughly 39 Kwh @ 80% DOD and another 25% DOD if that makes any sense is still 23 Kwh so a long way from the 14 you have of which you say you are only going to use 7 ? Very confusing to me and again sorry, but your statement is not practical or creditable IMHO. Fair enough but if all you needed was 7 Kwh, the LA pack could have been much smaller to begin with so it's still a bit apples and oranges to me. Your circumstances are the decision maker but they would not apply to all as a similar requirement. I have spoken to 2 Sydney Companies that Supply Used/ refurbed/ not brand new Traction packs that will warrant them for 5 Years for solar use with the provisos they are set up with an auto watering system and kepts topped up and not run below 80% DOD. If there is a problem they will come out, test? inspect and replace any faulty cells at their cost. If Nothing wrong or they have been used out of spec, I wear it. How long warranty did you get with your New Lipos and does the seller cover all replacement costs of shipping etc if there is a problem? I take it coming from overseas there is no local support for replacements if there is an Issue and you would have to wait for a replacement to be sent? This may be a personality difference in disposition. For $3500, I'd want to be CONFIDENT rather than hopeful because that's too much money for me to gamble. with. With a 5 Yr warranty on the LA being half that period and the Many experiences I have read about and a number of people I have spoken to in person that have gone well Beyond 10 years, I AM very confident in LA and the only doubts I would have is if I did something wrong and I think that too is a minimal risk with their straightforward and tolerant nature. Forums are full of people that have had disappointing results with the lithiums and to be blunt, If Tony can't make the things work I don't fancy my chances and I don't believe for a second his experience was just bad luck or a one off. I'm not a smart man but I am just smart enough to know to follow what the smart people do and when someone like Tony says I'm going LA, doing the same is as smart as I need to be. Yes and I sincerely hope they do work out well for you. Again though, The " sleep at Night" factor is significant for me and I know I'm going to spend less time worrying with LA than litho. Good on you for being brave and giving them a go. Not meaning to sound Catty but this does come back to what I mentioned previously. If your cells turn out to be a great success, it really won't help the worry worts like me. By then the formulation will have changed and I'll still be thinking if they are just as good or has the new formulation created some other problem or.... Guess I'm just too hard to please but I can find lots of evidence that LA is more likely than not to go the distance because it hasn't changed that much and for all I know they are still making them exactly the same as they were 10 or more years ago. I don't read of 3 yr failures put it that way. That is interesting and would seem to be an advantage. That said, I and others have presumed and said that they would have a week or whatever days capacity before needing to use a generator or whatever so the implication is there they (LA) would sit for some time in a partially discharged state. My question would be, in this application, how much does that matter? I'm sure the less you do it the better but again comes back to the thing one can't say I installed them today, they will need replacing on this date. I guess this sort of thing is taken as a given in their estimated life. I agree that the ability to sit for extended periods is an advantage the Lipos have, I just don't see it as a drawback of any significance in this application of LA. I have personally spoken to a Number of people where this was definitely not the case. The Clients with the dairy farm up the coast mentioned to me they are careful not to run them below 80% as specced and generally don't get them below 60% DOD. Also said the generator only really gets run to keep it running rather than let it sit but they do try to do this on a cloudy day so as to give the thing something to do and not waste the fuel. Couple of aspects I see to this. The cheaper batteries per KWH for me and what I have seen for people in Australia is LA is cheaper than Lipo. The second aspect is your situation. LA is impractical for you so cost is less of a significant factor if you NEED things because they are the only practical soloution. That's how it's going to be for EV's, power tools, portable electronics Etc. I have a battery hanging off my battery drill that I wave around in use no problem. It has the same WH capacity as the LA Alarm/ Brick type batteries that are commnon and I use for other things.... Portable but not hand held. I'd hate to be using a drill with the weight of one of those Brick batteries and I Imagine that's why they were never made till Nicad and then the lipos came in. I did have a 12V Nicad drill back in the day, several in fact. The battery duration and life was not good. Back then I disassembled a pack, wired it to a brick battery I wore around my waist in a Bum bag and was very pleased with that. was much better than trying to drag a lead up on a roof or dealing with a mains cord. Better now all in one but it was certainly workable and practical. I think the demand for Lipo is driven through practice not price. Tradie is going to pay a good amount of a battery tool with all it's advantages not the least Now Being OH&S. The cost simply gets priced into the job. Person that spends a lot of time travelling or out of the office is going to pay hundreds more for that laptop with a battery than one without. I think the majority would. When I think back to my own game again where I modified Alkaline Battery packs with leads running to SLA's for endurance and reliability, I'd pay a premium to retain the self contained setups I have now. I really think the demand for Lipo will only continue to increase through being the practical solution and peoples requirement for convince. The way the world is Pushing the EV idealism is sufficient to ensure demand I think. $4000 will buy you a 2yo or less 5 yr warranted 48V, 700AH pack all day long where I am. Seen them for as little as $2800 and just over $5K for brand new although I think that was a 600Ah pack. For MY application, there are basically No shortcomings. The advantages in fact for MY needs far outweigh and drawbacks. The only ones for me are weight and size and they are irrelevant. I would most likely put them in a garden/ power shed of their own although plenty of room in the garage. Weight, Meh, I'd make up a frame on wheels to put them on so I could move them round although I see no reason Id want to other than to install them and remove 10+ years later. Even If I had to hire a guy with a walkie forklift or a telehandler for that and I have 2 mates with forks and Cranes that could move them anyway. I built a large wheeled Engine Crane for shifting my stationary engines a few years back that would probably do as a one off as well. Your situation is different to that of most but certainly significant to you. Do you move your tiny house around? If not, is there any reason a LA pack could not be sat outside under suitable covering in theory? If you are not moving and have the trailer hard plumbed etc, then it's not really any more or less portable than the LA pack. One might just need to make 2 trips when moving house or hire a small truck with a Hiab to move them for you. Still trying to work out what the difference is between a " tiny House" on wheels and a Caravan? I used to work in a game where the participants were on the road a Lot and lived in Semis that were decked out and had slide outs and were 2 Storey with roof area and hard walled annexes. They weren't so tiny but they sure were luxurious! Generators and AC on them would outdo the demands of most homes. You are not going to save a lot over the cost of your lipos on LA but you WOULD have a lot more capacity. The BIG thing in LA's Favour for most of us here is bang for the back. You simply get more capacity for the same price with LA and for most the confidence factor of amortising and therefore lowering the daily/ yearly cost is more favourable. |
||||
| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Thinking about it, as you say, that's a decent car battery. My 4WD has Dual N70's so by this stupid rule, I wouldn't be able to change the batteries in my Vehicle. Most house batteries in caravans and Boats would be a lot larger than a Kilo as well. Bloody Ridiculous although completely self serving to the industry that stands to profit from this BS. Won't be from me though! Nah, Just bore them to death with a lot of environmental save the planet talk and tell them You use solar recharged camping lanterns at night and talk about saving every watt of electricity and how wasteful appliances are and how you have to unplug them when you are finished using them and you bathe in just a saucepan of warm water you heat on the gas BBQ and...... They won't be able to get out there fast enough! My fathers next door neighbour saves on power... He has an LPG camping shower sitting outside the bathroom connected to the garden hose with the hose for the shower head poking through the window...... Had that a couple of years now. Just need a Wifi switch connected to a relay. You can change over soon as you see them walking up the path without going near anything. Give it time. You know how many Licences you are supposed to have to work on cars Now? One for electrical, one for AC, one for engine, one for brakes, one for steering and suspension, one for tyres, one to fit tow bars, one for Child seats..... |
||||
| Page 4 of 5 |
|||||
 Print this page |
