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  • nebster
    replied
    Originally posted by SunEagle View Post
    I am not saying that a used Tesla battery can't be installed as a home energy storage unit that will last a long time.

    What I am saying is that the average person or even some that are electrically educated could still have a problem keeping the system going and above all SAFE.
    I was responding to the post by Sunking suggesting that there was no data on Tesla pack longevity.

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  • SunEagle
    replied
    Originally posted by nebster View Post

    There is a ton of user-submitted data from all over the world showing Tesla pack maxranges versus distance driven.

    https://docs.google.com/spreadsheets...Psg/edit#gid=0
    I am not saying that a used Tesla battery can't be installed as a home energy storage unit that will last a long time.

    What I am saying is that the average person or even some that are electrically educated could still have a problem keeping the system going and above all SAFE.

    Leave a comment:


  • nebster
    replied
    Originally posted by Sunking View Post
    Nice try Jeff, but all conjecture and not one documented case. Is a Green Mafia Blog site the best you can do?
    There is a ton of user-submitted data from all over the world showing Tesla pack maxranges versus distance driven.

    https://docs.google.com/spreadsheets...Psg/edit#gid=0

    Leave a comment:


  • Sunking
    replied
    Originally posted by jflorey2 View Post
    Agreed. That's why Teslas with ~160,000 miles on them
    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.

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  • bcroe
    replied
    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 Roe
    Last edited by bcroe; 10-31-2018, 11:50 AM.

    Leave a comment:


  • jflorey2
    replied
    Originally posted by nebster View Post
    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!)
    Agreed. That's why Teslas with ~160,000 miles on them (i.e. about 600 "full cycles" if you go from 0% to 100% each time, assuming a starting range of 240 miles) will still have, on average, 90% of their original range - because most of those cycles were shallower than that.

    (google "Tesla batteries will live longer than expected, survey finds" for more info on that)

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  • nebster
    replied
    Originally posted by Sunking View Post
    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.
    This is incorrect.

    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.

    Leave a comment:


  • Sunking
    replied
    Originally posted by magic8192 View Post
    This 500 cycles are full discharge, you get much more for partial discharge.
    I knew you would come back to counter punch with no data or facts to back up your claims. I get it, I am a Lithium Ion Battery advocate too. 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.

    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.

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  • J.P.M.
    replied
    Originally posted by magic8192 View Post
    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.
    Another endorsement and testimonial for u-tube - the new idiot's bible.

    Leave a comment:


  • magic8192
    replied
    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.

    Leave a comment:


  • Sunking
    replied
    Originally posted by magic8192 View Post
    evtv.me Those guys are using the tesla battery packs for home, he built a 100kW battery backup.
    I know Jack Rickert, owner of EVTV, for several years and met him at Bat-Com back in the 90's an we became friends. Jack is a Licensed Professional Engineer like myself and the countries leading premier custom EV builder. He is sharp and knows his stuff. However, and hate to tell you there is absolutely no compliant way you or anyone else can use salvaged EV batteries in their home. Real simple they are not listed to be used that way, and impossible for it ever to pass any inspection. That is just a fact of life, deal with it.

    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.

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  • jflorey2
    replied
    Originally posted by BoloMKXXVIII View Post
    Can't some EVs be used as emergency power for homes?
    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.
    Why not just buy an EV, use it and then if you ever need it for backup power - use it for backup power? That way you aren't paying for two cars.

    (BTW PHEV's and hybrids are even better, since they will run for days on a full tank of gas.)

    Leave a comment:


  • BoloMKXXVIII
    replied
    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.

    Leave a comment:


  • jflorey2
    replied
    Originally posted by SunEagle View Post
    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.
    Agreed.

    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.

    Leave a comment:


  • J.P.M.
    replied
    Originally posted by SunEagle View Post

    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..
    I'm not as concerned when people harm themselves after everyone with a brain and experience warns them. That just improves the gene pool.

    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.

    Leave a comment:

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