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  • #16
    Originally posted by Mike90250 View Post
    EV batteries get their many cycles by de-rating the battery capacity and only using the middle portion (30-80% ) of the cell capacity, as I understand it, the deeper the cycles, the less cycles you get.
    Yeah, and where exactly they set that is part of their "secret sauce." The first EV I had (a Leaf) charged to 4.1 volts per cell, max.

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    • #17
      Originally posted by Ampster View Post

      I think SK has been around Lead a long time. He knows what he is talking about when it comes to Lead Acid batteries. Less so with Lithium. He has the same attitude on another DIY EV forum and his Lead Acid views are largely ignored there.
      You are a liar.

      You cannot find one EV forum where I have anything to say negative about Li batteries other than the obvious facts. In an EV Li is the only real option. So stop you lying and quit making things up. If you would bother to look at very simple battery cut sheets, you would know Li battery cycle life is on the order of 400 to 1000 cycles at 80% DOD. So stop your BS.

      Here is the battery [U][I][B]cut sheet[/B][/I][/U] for Tesla battery. Go ahead and please look. Tell us they claim more than 500 cycles. I dare you.
      Last edited by Sunking; 03-31-2019, 10:21 AM.
      MSEE, PE

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      • #18
        Originally posted by Sunking View Post
        .......
        Here is the battery [U][I][B]cut sheet[/B][/I][/U] for Tesla battery. Go ahead and please look. Tell us they claim more than 500 cycles. I dare you.
        That is a cut sheet for a Panasonic 18650B. It is not directly comparable to the cells Tesla uses. Tesla has changed the electrolyte in their cells. Tesla warranties their car batteries for 8 years. Show me how that is not a lot more than 500 or 1000 cycles? I know, you are going to say they don't know what a full cycle is. Okay, then how many half cycles? Eight years is a long time, especially for a battery that I can use 60 percent or more of its capacity day in and day out.
        Last edited by Ampster; 03-29-2019, 04:16 PM.
        9 kW solar. Driving EVs since 2012

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        • #19
          Originally posted by Ampster View Post
          That is a cut sheet for a Panasonic 18650B. It is not directly comparable to the cells Tesla uses. Tesla has changed the electrolyte in their cells. Tesla warranties their car batteries for 8 years. Show me how that is not a lot more than 500 or 1000 cycles?
          Yep. And field data indicates that at 160,000 miles, Tesla batteries still hold 90% of their original capacity.

          https://cleantechnica.com/2018/04/16...-500000-miles/

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          • #20
            Originally posted by jflorey2 View Post
            Yep. And field data indicates that at 160,000 miles, Tesla batteries still hold 90% of their original capacity.

            https://cleantechnica.com/2018/04/16...-500000-miles/
            Bloomberg New Energy Finance recently reported that the Levelized Cost of Energy storage projects in 2018 was $0.187 per kWhr.
            Last edited by Ampster; 03-29-2019, 10:48 PM.
            9 kW solar. Driving EVs since 2012

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            • #21
              Points have been made for anyone to make up their own mind, no need to pour oil on the fire

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              • #22
                Yeah, so you experts didn't cover the differences of the hi or low dis/recharge rate types of the 18650's What type does Tesla use?
                Those who do, do it!

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                • #23
                  Originally posted by motorcyclemikie View Post
                  Yeah, so you experts didn't cover the differences of the hi or low dis/recharge rate types of the 18650's What type does Tesla use?
                  Tesla keeps some of that information closely held. From various sources I believe they have changed the electrolyte to get longer life. There may have also been subtle changes to anode or cathode. I have even less information about the new larger cells used in the Model 3.
                  Last edited by Ampster; 03-30-2019, 03:14 PM.
                  9 kW solar. Driving EVs since 2012

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                  • #24
                    Tesla uses a Panasonic NCR18650 cell Ampster. and you are proven liar.
                    MSEE, PE

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                    • #25
                      Originally posted by Sunking View Post
                      Tesla uses a Panasonic NCR18650 cell Ampster. and you are proven liar.
                      Liar? I agree the chemistry is Nickel/Cobalt/Aluminum Oxide and the dimensions are 18mm by 65mm.
                      How are you so sure Tesla has not changed the chemistry of the electrolyte? How do you know they are not NCR18650A or NCR18650BE or a custom arrangement with Panasonic? I notice you have taken the "B" off of your description. Does that mean you agree that what Tesla uses is different than the cut sheet you provided earlier?

                      How do you explain the fact that Tesla guarantees the packs in the car for 8 years?
                      What is not shown on the spec sheet is that when you partially charge and discharge, degradation of the battery capacity is reduced. Thus, you can do over 40 000 charge/discharge cycles when going from 30% to 70% only. Or over 35 000 charge/discharge cycles from 20% to 80%; 28 000 cycles from 10% to 90%; 15 000 cycles from 8% to 92%, 7500 cylces from 6% to 94%, and the capacity reduction goes faster and faster, finally reaching 500 cycles when recharging from 0% to 100%.

                      You have said yourself that this is how they get more life out of these batteries. Is that not true?
                      Last edited by Ampster; 03-31-2019, 12:52 PM.
                      9 kW solar. Driving EVs since 2012

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                      • #26
                        Actually the new Tesla Model 3 battery uses their newly developed 2170 cells
                        https://evannex.com/blogs/news/tesla...rk-in-progress
                        https://www.teslarati.com/inside-tes...m-ion-battery/
                        https://www.reddit.com/r/teslamotors...ns_calculated/

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                        • #27
                          Originally posted by Ampster View Post
                          Liar? I agree the chemistry is Nickel/Cobalt/Aluminum Oxide and the dimensions are 18mm by 65mm.
                          How are you so sure Tesla has not changed the chemistry of the electrolyte?
                          Good article on Tesla batteries:

                          Dang, can't post the link. Search "model 3 batteries cobalt volkswagen."

                          Comment from the page:

                          "This is factually incorrect. Panasonic has provided the original manufacturing equipment, the license to the original chemistry, and processes to build the cells today. The chemistry used by Tesla today is not sold in any Panasonic batteries sold today since it is exclusive to Tesla and hence is why all other manufacturers are trying to come up with their own composition. Panasonic involvement today is solely aiding in battery production and quality checks. They may end up having to license it through Tesla.

                          Tesla has a chemistry RD department that parents over the multiple subsidiaries and contracts with other international entities. This is headed by Green Bay Wisconsin raised, JB Straubel. Think of it more as a hybrid between traditional chemistry R&D and contractual outsourcing. About 2/3 of the department budgetary goes to a fluctuating, currently, 19 different partnerships and contracted engineering organizations that focuses explicitly on battery chemistry and process."

                          In other words, it's not a Panasonic NCR18650B.

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                          • #28
                            Anyone know some good crow seasonings / recipes ? I think Sunking blew this one, which is why I say he's [U]nearly [/U]always right.
                            Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                            || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                            || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                            solar: http://tinyurl.com/LMR-Solar
                            gen: http://tinyurl.com/LMR-Lister

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                            • #29
                              Originally posted by jflorey2 View Post
                              ............

                              Tesla has a chemistry RD department that parents over the multiple subsidiaries and contracts with other international entities. This is headed by Green Bay Wisconsin raised, JB Straubel. Think of it more as a hybrid between traditional chemistry R&D and contractual outsourcing. About 2/3 of the department budgetary goes to a fluctuating, currently, 19 different partnerships and contracted engineering organizations that focuses explicitly on battery chemistry and process."

                              In other words, it's not a Panasonic NCR18650B.
                              Most of what I have said on this forum about the future of Energy storage, I have learned from watching videos of JB Strauble's speeches and presentations. I have also picked up some information from technical publications. I think he has done a lot to improve the performance of the batteries in those cars. I am sure he also collaborated in leveraging the battery technology into energy storage via the Powerwall and the Powerpacks.The Powerpacks are used in commercial and industrial as well as grid scale implementations.

                              JB Straubel started at Tesla before Elon Musk made an investment and took control of the company from some of the original founders. JB actually built an EV when in college..

                              Tesla also hired as a consultant, Professor Jeff Dahn from Dalhousi University who has done some work on predicting cycle life of Lithium batteries. He is one of the consulting partners mentioned above. I think it was one of the videos of his lectures and TEDX talks that clued me into the subtle change in the ectrolyte that has contributed to the long life of those batteries.

                              Thanks [USER="30916"]jflorey2[/USER] for the above and for starting this thread in the first place.
                              Last edited by Ampster; 04-01-2019, 09:49 PM.
                              9 kW solar. Driving EVs since 2012

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                              • #30
                                Originally posted by Ampster View Post
                                Tesla also hired as a consultant, Professor Jeff Dahn from Dalhousi University who has done some work on predicting cycle life of Lithium batteries. He is one of the consulting partners mentioned above.
                                Jeff gave one of the keynote talks at the International Battery Conference I was at last week. Very capable guy.

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