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Forum Index : Solar : Li -ion battery
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Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I have no experience with lipos other than using hem in equipment they were installed in. Nothing with building battery packs and charge/ Discharging them. What you say fly's in the face of about everything I have read of them. Hardly surprising though given I do know about LA and the facts of those batteries are completely misconstrued as well. Seems so many people will say anything to prove their position is right. What I have read repeatedly is with charging the Lipo packs you just set them at whatever rate up to C1 and they will charge at that rate till they hit end voltage and you then turn them off. Matter of fact, the common folklore touts this as an advantage as you don't need " Complicated" chargers that back off once the battery hits 80% Like you do with LA and therefore the Lipos will charge in a fraction of the time LA will. May be true to a degree but then I also read it is extremely wise if not essential to have a BMS so what the imagined difference is I don't know. Obviously not the case as made out and as you quite rightly say, Most people don't have a clue . Won't stop them parroting everything they ready though to push their vested interests. I have never denied Lipo has a lot of advantages but I don't know why the proponents have to outright lie and exaggerate the the facts. They are an inanimate object, they are what they are, that's it. The other thing I read every singe time in a most discussions with house hold batteries is that lithium will become cheaper. I find that a laughable statement. They have already had their initial price drop from when they were a new technology and to think they would keep endlessly becoming cheaper, usually under the flawed assumption that increased production is the only cost factor, is ridiculous. I point out that LA has been around many decades, are made by the 10's of Millions in the automotive sector alone but every time I go to buy one they have gone UP not down in price so why should Lipo be different. Of course most suggesting this cheaper fantasy overlook the basic fact that any product in High demand and limited availability is only going to go up or maintain price, not go down. Supply and demand which the real world operates on in manufacturing is the controlling force not Ignorant Opinions trying to push a cause. Everything I read from real worlds sources says Lipo production can't keep up with demand and they want to build more production facilitates but are also hitting problems with supply of raw materials. Only a few relatively politically unstable countries with questionable labour and environmental practices in the refining of the materials produce the raw product so not like it's available in unlimited supply. Tesla power walls went up twice last year so increased production certainly wasn't making them any cheaper. Lipo certainly have their advantages but cost over LA is not one of them and I can't see it really being one in the real world despite what many make out. |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
I guess Its time for an update. After the first few attempts at charging appeared to have some effect on deflating the cells, they charged a little and then self discharged till completely flat, generating heat in the process. The next attempt was the capacitor shock treatment......just experimental to start with. The packs are divided into a set of 3, so working with one pack in my spare time,I set the battery charger to 17v connected to telephone wire between the charger and a 34000uH 40VDC capacitor, with some (sacrificial) copper wire connected to one cell in the pack. Charged up the cap and then SPLAT the wire onto the connector on the cap (went to the battery terminal on the others), for about one second (any longer and the wires would produce too much smoke), Did this a few times then let it sit over night and that cell was holding .4volts. I did the rest of them with about 9 dumps from the capacitor and the cells when to about .5 to .8volts each, left for a few days and checked the voltage, all of them were showing some voltage still, so charged them as a pack to about 2.5v each, left them sit for a few days and checked again, voltage varied a bit over all of them, but 2 cells where much better than the others, after this it looked obvious that the other cells need a bit more help......I give all the cells another 9 hits (a total of 18 hits) each and then charged them some more up to 2.8v each and left them sit, of course they dropped back a little due to resistance. Charged the pack again to a little higher voltage and they are holding quite well, still not at full charge yet, next it was time to see if the same procedure works with the rest of the cell"s I hadn't taken any proper power reading's up until now as it was experimental to see what happens. With a battery charger that can supply large amperage and a clamp meter over the wire going to the cell, the first zap measured about 50Amp as it is almost a dead short, just to confirm that, the amp meter needle on the battery charger went past 40Amp and hit the stopper. The next zap (measured on the clamp meter) was about 45A then next was 40A and so on as the resistance of the cell increased. The last pack of cell's, I only give them 9 dumps from the capacitor & charger, just to see if the results would differ. As it turns out, the last pack has a will not charge as high or fast as the others. After leaving all the cell packs sitting for some time, checked the voltage of each cell to see if the voltage is close enough to parallel wire the lot, so yes they were, wired them together and left them sit for a day to equalise. After the Cell's Been sitting for a week or so, it was time to put them into the flat pack and connect up the balancer, I had tried charging the cells when connected to flatpack balancer previously, but it was unresponsive, Initially I thought it might want some decent amount of voltage in the cells before it would work......but no, it would not respond with 40v from the battery, and still no response with a pair of solar panels connected to the flatpack terminals. Time for some fault finding, Underside of the balancer, can see a row of balance resistor's, couldn't see anything unusual. More checking and probing around on the common port under over voltage MOSFET board, found a shorted diode on the power supply section, this took out the PTC fuse that supplied that section. It was a bugger to trace this thing, there is a middle layer in the pcb that carries the positive power. Could not find information on this diode, so replaced in with another smd diode of similar size....well it all fired up when connected to the batteries, looks promising, after about an hour all lights are out on the circuit boards, bugger. Checked and found the diode shorted again, (I do not have any SMD stuff around, just grabbed something from old unused circuit boards) replaced it with another different one that was a little larger looking but unknown value, soldered it in, connected power and the diode failed immediately, something else may be wrong? Just get a 1n4004 bend&cut the legs and solder that in place...it will fit. Ok it now works with that diode in place and no heat on components, still don't think its doing what it should, some of the LED's are not as bright as the rest, for what ever reason. The 2 LED's on this board indicate the charge and discharge mosfets low voltage cut off, one led will go out, the other will be off when voltage goes high....normal operation.....what is not normal is that either of them will switch off with know reason at all that I am aware of, started at 48.4 I had the inverter running off it for a short time, and it just cut power to the inverter at 48v, could be SOC setting that is not working or setup. Charging the flatpack the row of LED's indicate the cells that have a higher voltage than others and are in the process of lowering the voltage of those cells, This section appears to be functioning normally.....enough to burn a finger on those resistors after a short time. Another issue or several....charge will often cut out and restart for no apparent reason, don't what to blowup an inverter connected to it when that happens. When the (cells are full) charge exceeds what the balances can handle it cut the input power.....as it should, however the fault led comes on and shrieking noisy buzzer starts up and as yet, will not turn off without actually removing the positive power wire. What we could do is put an external switch on this positive wire to either reset when this fault occurs, or it will also be used to turn the power off to the unit, as there is no other way to turn it off. The large black wire is negative power in and out of the battery, what we could do here is splice a heavy wire into that and run that to an inverter or appliance or whatever, to avoid all the strange on off behaviour, however this would bypass the low voltage cutout rendering it useless....use an external low voltage cutout, should do the job. For charging, the normal ports (outlets) should be used, this will still use the battery protection and work in its normal way...Normal? Whats that? The reason for this flatpack's behaviour, with its power on off on trickery, could be that the flatpack in supposed to have a control unit connected to it, that connects to net where setting and commissioning of the system is performed, also according to the manual the power led should flash and the button should put the flatpack into sleep mode when pressed for a few seconds, but NO it wont do that. These are not build to be stand alone, as far as I can workout. The user manual "sonnen-943-user-manual.pdf" has some info in it, but I see this. Not sure what was the cause of the flat cells, could have been left sitting on the shelf too long and discharged till completely flat, or some fault on the control boards. So after all this, giving these cells some shock treatment has revived all of them, but still many unknowns, they have swollen back up a little (wouldn't be noticed with cylindrical cells), the capacity is unknown although I did put in over 400Wh into each of the 3 packs (about 1.2Kwh overall) there was some time spent charging after that, don't know how much. The batteries prefer to hang around 3.33 volts each, so just shy of 50volts total, as this is 15 cells instead of the 16 that most others use. Some cells are different than others, but there is some usable capacity there. Don't know how long it will work or last, it could improve or it could fail after a few cycles, it might want another ZAP from a capacitor again. At the beginning nothing was working at all, So I think it was worth trying this method out. Cheers Aaron Off The Grid |
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi Aaron. You certainly are gifted with patience, and ,of course the intelligence to figure out faults ,well done. Thanks for all your work, maybe one of us will find a home for it...or a boat , that needs an anchor,LOL. I'm progressing steadily with my inverter, am doing metalwork to fit the DC input switch and the capacitor soak function. So, have fun with the flatpack, Bruce Bushboy |
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Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I believe one ( or more) of these Lipo type chemistry's can also go off in spectacular fashion if they get wet or have water ingress. Tossing it overboard and getting Boiling seas reaction may be fun but don't think it would do the Fish population a lot of good! |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
I had a discarded, but new 40v Li battery (think it was a Ryobi 40v battery), it was a bunch of 2.2Ah 18680's, I divided it into 2, so I could use them as 20V packs, left one sitting at the edge of the table outside where I was working, days later went out to get it!...wasn't there, thought I must have shifted it. A few days later the Stainless steel bucket of watered down molasses near the table had a good amount of bubbles and foam in it, didn't think much of it at the time, later on I needed the bucket, tipped it out and found the 20v battery with a good amount of electrolysis eating through the cells, Turns out It was the birds (little green Lorikeet's) playing with it and knocked it off the table. On the Spectacular scale, I give it a 1 out of 10. Cheers Aaron Off The Grid |
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Rest assured, Dave99, as Aaron or myself would never throw batteries into ponds.creeks , dams, or the salt seawater areas... Looks like I'll have to take care when I'm posting such sensitive suggestions . Bruce,just a dumb busboy. Bushboy |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
Not to worry, It reminds me of some electro fishing I did in a small dam, used probes. Edited 2021-10-27 14:57 by Revlac Cheers Aaron Off The Grid |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
Edited 2022-02-05 06:13 by bob.steel |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
I see you are a newbee . This is mostly rubbish and should be withdrawn or at least strongly edited . Its gossip spreading . |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
If you are silly enough to short any battery it will smoke . Why not weld up your car if you are going to do that. |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
I don't know why you insist on posting this rubbish . Its gossip and wowserism dave. Water dilutes ethylene carbonate . There is no reaction it just takes longer to evaporate . Toss any battery in water and it will likely discharge as and if the terminals are shorted ,like in salt water perhaps ,but nothing you will notice. |
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bob.steel Senior Member Joined: 27/02/2020 Location: AustraliaPosts: 188 |
Bugger . This silly no edit rule catches me every time . Why the hell do that Admin? I wanted to go back and remove the duplicated pictures but can't.Your editor is the worst I have seen.It needs fixing. Forgive my enthusiasm fellas. I just came across this topic again and wanted to share something with you but started reading and saw the comments needed correcting . Did not see I had started correcting it before . Anyway News First go to lfp for really good info on LFP /LiFePo4 batteries and On Ebay , States and Australia is a seller called Digi-Marker. Their 200 Ah 12 volt battery for instance sells for about $800 AUD That battery has Alloy Prismatics in it . All their other models below that have cylindrical cells made by them of about 136 mm by 33.5 mm . They are cheap and directly price comparable to lead acid stuff NOW. 10 years at least life and 100% discharge without damage ! On that site above I have pulled most of the models apart to verify the truth of their claims and they have checked out. No excuse now to change over when your next set of lead batteries destroys itself. Cheers. Edited 2022-02-05 07:19 by bob.steel |
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noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 512 |
ok, lets get this straight.. you say they are " comparable " with lead acid on a stationary system.. i just purchased a 2nd hand 48v 700ah forklift battery from CEIL Australia for $5600 delivered to my door... with test papers and warranty... to get the same capacity from your lipo cells by your maths (800ah) would cost me $12800, then bms etc on top... not really " comparable "... lipo is great, but in this instance its not viable ... I'll easily get 20 years out of these cells, they are extremely hardy for forklifts and are rated at 5 hr rate... but each to their own I think it works !! |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
SECOND HAND FLA batteries COMPARED to NEW price Lipo Batteries? last I looked it was $11,000 to $16,000 PLUS Delivery for new 750AH lead batteries. New price for either is not a viable option, Most of us would go for the cheaper option, no point in spending big $$$ depending on circumstances. Cheers Aaron Off The Grid |
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noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 512 |
all i was saying is exactly that, unnecessarily expensive when FLA CAN be loads cheaper and just as reliable, heck for solar my personal experience is they are wayyyy more forgiving... yes i will concede that " new " may be " comparable " but it is unnecessary when there are far better / cheaper options... as many on here have come to experience, lipo batteries can be a right pain and don't live up to the hype with longevity and dod... I think it works !! |
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I plan to get a rebuilt and reconditioned and warrantied battery from Ceil very soon. Thirty to thirty five Kwh storage is vastly more than I really need, but the capacity can gradually fall away over the years, and it will probably last longer than me anyway. Cheers, Tony. |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
The LYP cells require one to come up with one's own strapping method and, if not done very well, will swell in the middle too.I think you mean LFP No, its *LYP*, look up 'Winston' sells |
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Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I'm on an off grid forum and you can't even Mention LA or traction batteries or 20 tryhards will just down your throat and call you an idiot for even thinking of them and then make up every lie and talk endless crap to make Lipo seem beyond perfect and LA beyond useless. I don't know what the Obsession many have with Lipo these days. I keep hearing the " Lipo is cheaper story but I have Challenged a Number of people now to show me where they can get lipo, in Australia from a bricks and mortar store Cheaper than the same usable capacity in Traction batteries. Of course the excuses and Insults are plentiful but the answer to the question remains unanswered. I can't remember seeing anything people were so utterly obsessed with pushing the barrow for and getting so upset if people should have a Differing opinion. The lies alone to champion their position are incredible. Even when you link them to manufacturers information they just dismiss anything that is no complimentary to what they want to believe and talk opinion which they can never back up a a law of the universe. It's worse than religion or politics. If you prefer Lithium, great, no skin off my nose what you use. Likewise, If I prefer LA, why are others getting their panty's in such a twist? Does not affect them one little bit. I just don't get why these people are so hung up on inanimate objects like batteries and why they are so hell bent on pushing their proclivities on everyone else?? BTW mate, you do know according to these tryhards on this other forum I look at and some others I have seen, Your La pack is only going to last 3 years tops, You will be maintaining it 12 hours a day and if you discharge it any more than 20% it will be ruined. Trust them, they know cause they read the same thing 3 Times on the net so it has to be inarguable Fact! Love to see some pics and a write up when you have it set up mate. How many panels and what size are you hooking up with it? |
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