Tesla battery pack?
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Awww... and just when it was starting to get interesting and I was about to add him to my "YouTubers who Use Raw Tesla Packs and I'm Waiting to See Who's House Burns Down First" List. But I know, Safety First! I am clearly in the "99%" group, but it is amazing to me how many people come here with and idea that gets tweaked or shot down as dangerous but want to argue their method anyway. You Mods and Super Contributors certainly do have your work cut out for you here, and I appreciate your guidance in putting safety first (not that you need my thanks or acceptance)
I have just seen to many people get hurt because they got complacent with electricity and batteries and then made a mistake which blew up in their face or electrocuted themselves..Comment
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You are welcome. I am always looking for new technology or ways to improve the use of solar hardware but am cautious when people make claims too quick when they say it is safe.
I have just seen to many people get hurt because they got complacent with electricity and batteries and then made a mistake which blew up in their face or electrocuted themselves..
The sad part to me is the dumbasses' lack of consideration that puts others in jeopardy or causes others to struggle or pickup after the assholes.Comment
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Actually I made the statement that 99% of the people would not be able to "safely" use a Tesla battery for home energy storage. I think that number is really high because without a good electrical circuit knowledge and some common sense most people will kill themselves playing with something like that.
Used EV batteries are a great source of raw battery packs. Unfortunately people hear that, and they jump to the conclusion "so I can just hook it up to my inverter and away I go!" Then they order it and start working on it with uninsulated tools, without cooling and without a BMS. And they are shocked when a dropped wrench causes a fire. Then they start looking around for someone to sue.
On another board a guy related how a bad Ebike lipo battery burned his garage down. (He was VERY lucky that it didn't burn his entire house down; kudos to the fire department.) That was a commercial pack, relatively well designed as these things go. I hope that doesn't become commonplace due to people who "found a good deal" on a used, unprotected EV battery.
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Can't some EVs be used as emergency power for homes? I always thought if I was going to use an EV as a energy source/storage for my home I would pick up one and park it behind my garage (put a shed over it), remove things that were not related to the battery/charging system (tires, seats, etc.) and use it complete. Maybe not the most energy efficient way of using the batteries but it has to be a lot safer than yanking out the batteries and rolling your own system.Comment
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Sure. Install a good connection to the 12V battery (like some 100A Anderson connectors) and have a 12V inverter ready to go. Most EV DC/DC converters will handle about a kilowatt, so you can likely draw 500-800 watts from the EV.
I always thought if I was going to use an EV as a energy source/storage for my home I would pick up one and park it behind my garage (put a shed over it), remove things that were not related to the battery/charging system (tires, seats, etc.) and use it complete. Maybe not the most energy efficient way of using the batteries but it has to be a lot safer than yanking out the batteries and rolling your own system.
(BTW PHEV's and hybrids are even better, since they will run for days on a full tank of gas.)
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Can it be done? Sure it can if you are foolish enough and do not value your life. I really do not care if fools kill themselves, makes the world a better place. Next in line is why would you want a used battery that the battery manufacture only claims 500 cycles? Are you that silly? Yeah I know you are laughing right now along with the rest of the uniformed public that Tesla Batteries are only good for 500 cycles. Every battery manufacture data sheets are notorious overly optimistic and exaggerates cycle life. So anyone who tells you thousands of cycles does not know what they are talking about with respect to Tesla EV batteries or any other EV manufacture, and if you bothered to click the link from Panasonic data sheet and did your homework, you would know they only claim 500 cycles and that is a FACT JACK. So why anyone would use used EV batteries has not done any homework of cost evaluations. Wanna buy used Condoms and save some money? They deserve to loose their money.
Tesla uses Panasonic NCR 18650PF Cells. The reason they use those cells is real simple; Energy Density. It is the only way they can get 300 miles. It means they are the highest energy density cells you can buy. It also means they are the most dangerous and unstable cells, and the type that gives Lithium Ion Batteries a bad name and banned from air shipments. Tesla has to use use thermal management to keep them from catching fire.
Want Tesla EV batteries to run your home? Well Elon has a SCAM made for you he calls the Powerwall. Listed and tested to be used in RE systems in your home. Point here is you can certainly used Lithium Ion Batteries for your home Solar Systems. Many manufactures make them, but that will be be a fixed voltage much higher than you can assemble and make yourself, that are listed and tested for residential use.
As for the forum shutting down and calling out unsafe practices is in their best interest. They can be sued into bankruptcy otherwise if someone takes bad non-conforming advice from the forum, the survivors will find the best Ambulance Chasing Attorney the Forum cannot afford.
Last edited by Sunking; 10-30-2018, 03:47 PM.MSEE, PEComment
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This 500 cycles are full discharge, you get much more for partial discharge. The capacity goes down in a linear fashion as time and cycles add up. There is a good deal of data on Tesla batteries and most of it is looks really good for lithium-ion. The guy on teslanomics has looked at the data on tesla batteries and suggest that tesla batteries will last up to 25 years. https://www.youtube.com/watch?v=Gb_i4ihsJ1w This will most likely be less if you are doing a charge/discharge daily, but if you get 1/2 of that, then that is 12.5 years, not bad for batteries.
I think you are being a little dramatic with the "foolish and do not value your life" statement, but if there is some liability I am not aware of, then I will stop posting about Lithium-ion. BTW, I am not an advocate of burning down my house either.Comment
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This 500 cycles are full discharge, you get much more for partial discharge. The capacity goes down in a linear fashion as time and cycles add up. There is a good deal of data on Tesla batteries and most of it is looks really good for lithium-ion. The guy on teslanomics has looked at the data on tesla batteries and suggest that tesla batteries will last up to 25 years. https://www.youtube.com/watch?v=Gb_i4ihsJ1w This will most likely be less if you are doing a charge/discharge daily, but if you get 1/2 of that, then that is 12.5 years, not bad for batteries.
I think you are being a little dramatic with the "foolish and do not value your life" statement, but if there is some liability I am not aware of, then I will stop posting about Lithium-ion. BTW, I am not an advocate of burning down my house either.Comment
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But I do not give a rats behind what you claim or think, and the flip or Counter Punch is Lithium only claims 500 cycles to 80% DOD with absolutely no warranty or 1 year at best is pretty piss poor because there are many Pb batteries that will give 1000 to 2000 cycles to same 80% DOD. Treated it like apples to apples comparison being up front, Pb up against a NCA Lithium limiting daily discharge to 25 to 30%, with PB you go up 2500 to 5000 cycles smoking any Lithium cycle life for 1/2 the cost of used condoms, and cum with real 7 and 10 year warranties with several of those years full replacement cost.
To be up front I do own used Leaf Batteries for a good reason, they are in my golf cart where the economics and sacrifices are justifiable with 1/4 the weight @ 1/3 the volume. I have had them for 2 years now, and they need replaced. If not for that, EV manufactures would not use Lithium. When the day comes economics and safety issues are equalized, I will be right behind using Lithium for off grid systems in homes. As for now I can only advise lithium used in rare RV or mobile applications where life safety and economics are relaxed. Pretty easy getting out of an EV RV, or Toy Hauler on fire. Now if you have the knowledge, experience like Jack and experts have willing to take a chance and accept the consequences, gofferit. But to go and suggest DIY to go buy used EV batteries and use them in your home is plain and simple dangerous and irresponsible. If a person is willing to pay up for it, there are quite a few manufactured Lithium Off Grid Batteries on the market made listed, and tested to do what it is intended to do. They will be in cabinet you cannot get into, have the required safety controls, and thermal management systems required. The only one I would stay away from is Powerwall made by Tesla.Last edited by Sunking; 10-30-2018, 08:01 PM.MSEE, PEComment
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You are correct about partial discharge extending cycle life, but very misleading and exaggerating a great deal. The 500 cycles is stated at 80% DOD, not full discharge as you said. I agree if you limit charge to 90% SOC and DOD to 20%, you can double to quadruple cycle life. That is a known published fact backed by real data Far short of your exaggerations and no case history of any EV battery lasting more than 5 years to 80% rated capacity. Anyone ever seen a 5-year old year cell phone or laptop battery? You have no data to back up what you claim, just YouTube pretenders and wannabees.
The Panasonic 18650s are rated to ~70% of their original capacity after 500 full cycles: 100% to 0% SOC and back. Of course, lifespan increases dramatically if one elects a narrower charge regime. And lifespan increases if temperature is kept lower. And lifespan increases if cells are held at less than 100% SOC during periods of non-use. (And, by the way, 70% of nominal capacity is far from used up!)
None of that is to say that cobalt chemistries are super safe or that everyone should just go wire some crashed packs into their house. But, setting thermodynamic risks aside for a moment, it is clear that NCA and NMC chemistries can be cost competitive in a wide range of use cases.
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The Panasonic 18650s are rated to ~70% of their original capacity after 500 full cycles: 100% to 0% SOC and back. Of course, lifespan increases dramatically if one elects a narrower charge regime. And lifespan increases if temperature is kept lower. And lifespan increases if cells are held at less than 100% SOC during periods of non-use. (And, by the way, 70% of nominal capacity is far from used up!)
(google "Tesla batteries will live longer than expected, survey finds" for more info on that)
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What I saw on lead acid was that a battery could be exercised a certain number of AH (or KWH) and
then it was worn out. That total varied only a small amount between deeper discharge cycles and
shallow. Sure it will go more cycles with shallow discharge, because you have not handled
nearly as much energy (per cycle).
I suppose other limited cycle batteries are similar in this respect. It is going to take so many KWH
to move an EV 160,000 miles, whether you recharge it at 50 miles or 150 miles, and the battery
wear is going to be about the same. Bruce RoeLast edited by bcroe; 10-31-2018, 11:50 AM.Comment
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Nice try Jeff, but all conjecture and not one documented case. Is a Green Mafia Blog site the best you can do?Last edited by Sunking; 10-31-2018, 10:16 AM.MSEE, PEComment
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Nice try Jeff, but all conjecture and not one documented case. Is a Green Mafia Blog site the best you can do?
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