Tony Williams wrote: -------------------- Here's my guesstimate: *********************** Here is the Tesla 85kWh battery specs: 3100ma Panasonic 18650 cells 7104 total cells 16 battery modules are connected in series. There are 6 sections in one module also in series, and each section of 74 cells is connected in parallel. ******************* So, a 45kWh battery in the Rav4 EV will be 45/85 the number of 3100ma cells, or: (45/85) * 7104 = 3760.94 cells We need 3100/2900 more cells for the smaller 2900ma cells in the Rav4 EV, or: 1.06896552 * 3760.94 cells = 4020 cells in Rav4 EV ******************** smkettner wrote: What is stopping us from using the 3400 mAh version? Well, I expect by the time this project is actually needed, there will be 4000ma cells. 45kwh/2900*4000 = 62kWh ================================ The Rav4 EV pack is almost exactly half the size of the Tesla 85kWh one. Actually, i might be fooled to think it is exactly half, except i think they used 2900ma cells, vice 3100ma. When the car is fully charged, the cells (i don't know if this is individual, or groups of parallel cells) are 4.1 volts. At the "normal" charge of about 90%, the cells are about 4.05 volts. This, by the way, is exactly the voltages that the Nissan Leaf uses. I drove tonight about 75 miles from Orange County to San Diego. I started around 54% SOC, with cells around 3.7 volts. I drove the car all the way to "Turtle", which occurred at 2.9% SOC. I continued to drive the car to 2.4% SOC, but the battery contactors did not open and i was in my garage. For the 75 miles, the car reported that I used 21.993kWh, and regenerated 889kWh, for a net of 21.104kWh (yes, it actually gives all three values). The cell voltages sagged significantly between 2.8xx volts and 3.2xx volts while driving at this low SOC%, entirely dependent on load. Once in my garage at 2.4% SOC, the cells reported 2.930 volts low to 3.122 volts high under no load. We are compiling all the data as part of our "JdeMO" project, to offer CHAdeMO quick charging to Rav4 EV, Mercedes B-Class ED, and Tesla Model S (no adaptor required!). More tidbits: Low Battery Warning - 19.3% SOC Very Low Battery - 13.9% SOC Flashing gas can - 11.9% SOC "LO" on the GOM - 8.4% (NOTE: cell voltages 3100-3190ma) Climate Control Limited - 7% Turtle - 2.9% No cutoff by 2.4% =================================================== Can you tell us what the vehicle charges to (total pack voltage) in both standard and extended modes? With 4.1 cells, and 74 cells per module * 6 * 16 (the same 96 cells in series as a LEAF) = 393.6 volts pack voltage in a Tesla Model S. Obviously, I don't yet know the configuration of our pack, but I'll bet it's still 96 cells in series. The "80%" is about 4.05 volts per cell, and is actually about 89% SOC. I think it's about 83% in a LEAF. ------------------------------- Kohler Controller wrote: ... So I'm pretty sure it is 92S. As for the number of cell in parallel, my money is on 53P which puts it about 49kWh, with 41.8kWh usable. I'm pretty sure Tesla products are the same way, which is a 100kWh pack for the Model S85. I think you're probably right about 92S for the Rav4 EV, however we already know that the Tesla 85kWh pack is 96S, with 16 modules each of which have 6 "bricks" of 74 parallel cells. 7104 total cells = (6 * 16) * 74 4.15 volts per cell * 96 = 398.4 pack voltage (Tesla Model S-85) 4.15 volts per cell * 92 = 381.8 pack voltage (Rav4 EV) -------------------------------------------- Tony Williams wrote on 10/07/2014 I just did a full range test on #2496: 10,800 miles Full charge to Turtle mode 116.4 miles 2.9 miles per kWh from 40.14 kWh calculated burn +/- about 0.5 39.4 kWh reported net burn from CAN bus (48.2kWh burned, 9.3 kWh regen) 0.5 kWh estimated remaining usable energy (1.4% * 39.9kWh) 41.8 kWh advertise useable when new at room temperature 1.4% SOC 2.992v - 3.096v - minimum / maximum resting cell voltage 278.72v - resting pack voltage (92 series configuration) 30C - 32C - minimum / maximum cell temperatures 39.9 / 41.8 = 95.5% capacity from new (4.5% loss, however full charge was only 97-ish%) 4.2 - maximum cell voltage during regen 4.14 - maximum observed resting voltage (I believe 4.15 is probably specification) 2.5 - educated guess minimum cell voltage before auto shutdown ----------------------------------------- RAV4 degradation, Fuel Bars A brand new RAV4 EV battery - loss of 5.1% SOC per fuel bar until 48.1% SOC 12% degraded car at 50,000 miles - Loss of 5.4% SOC per bar until 51% SOC, then 4.5% SOC with variations per fuel bar below 51% ****** 35kWh / 41.8kWh = 83.83% of usable capacity when new for a full "normal charge". Full "extended" charge - 96.5%- 98% SOC, 4112mv-4114mv per cell ****** When car is turned on to READY, voltages drop to 4100-4106 with A/C pump running. Normal charge - 88.9% (12% degraded car), SOC 85% (new car) FUEL BAR SEGMENTS @ --------12% degraded ---new battery 16 gone - 83.4% ------ 78.7% 15 gone - 78.0% ------ 73.6% 14 gone - 72.6% ------ 68.5% 13 gone - 67.2% ------ 63.4% 12 gone - 61.8% ------ 58.3% 11 gone - 56.4%------- 53.2% 10 gone - 51.0% ------ 49.1% 9 gone - 46.4% ------ 43.7% 8 gone - 41.9% ------- 39.5% 7 gone - 37.4% ------- 35.3% 6 gone - 32.9% ------- 31.1% 5 gone - 28.4% ------- 26.9% 4 gone - 23.9% ------ 22.5% 3 gone - 19.4% ------ 18.3% (Low Battery Warning) 2 gone - 13.9% ------- ----- (Very Low Battery) Flashing gas can - 12.9% LO - 8.4% 1 gone - 7% SOC (Climate Control Limited) Turtle - 2.9% ------------------------------ TonyWilliams wrote: Ok, here's some real data: This is a Turtle to 100% "extended range" charge: 2012-Nov-18 Average Power: 7.202 kW (Blink 30amp EVSE) 00:57:03 until 08:10:32 - 49.909 kWh (7 hours 13.5 minutes) Looks like a little cell balancing followed by a top off charge two hours thirty minutes later: 10:40:58 until 11:07:04 0.509 kWh (26 minutes) So, what can we learn from this? 1) I'm quickly warming up to the idea that the battery is really bigger than I originally thought, which means it's a REAL PIG in efficiency !!! 2) 49.909 + 0.509 = about 50.4, but some of that was discharged during the cell balancing. I'll say 50.2kWh. Then, we have to estimate the charger efficiency, which I'll just say 85% = 42.67kWh in the battery Then, we have to add about 2.39% at the bottom of the battery of the battery = 1kWh (0.0239 * 41.8kWh) 42.67 + 1 = 43.67kWh stored energy (about 87.3% of estimated 50kWh advertised / rated size) Then, I'll take 94.75% of that (0.9475 * 43.67) = 41.4kWh calculated useable capacity Ok, I will believe that there is 41.8kWh "officially" useable in that 860 pound battery. Don't ya just love numbers? NOTE: All of this is assuming no power was used for battery temperature control (or more accurately, the 85% charger efficiency reflects all power losses). ========================================= TonyWilliams 92s * 48p = 4416 cells * (2600mah * 3.65v) = 41.9kWh (2012-2014 RAV4 EV) 84s * 44p = 3696 cells * (2600mah * 3.65v) = 35.1kWh (2014 - newer Mercedes B-Class ED / B250e) 99s * 69p = 6831 cells * (2600mah * 3.65v) = 64.8kWh (Roadster) 96s * 86p = 8256 cells * (3400mah * 3.65v) = 102.5kWh ("100" car) 96s * 74p = 7104 cells * (3400mah * 3.65v) = 88.1kWh ("90" car) 96s * 74p = 7104 cells * (3100mah * 3.65v) = 80.4kWh ("85" car) 88s * 22p = 1936 cells * (2600mah * 3.65v) = 18.3kWh (Smart ED) 84s * 74p = 6216 cells * (3400mah * 3.65v) = 77.1kWh ("75" car and software limited "70" and "60") 84s * 74p = 6216 cells * (3100mah * 3.65v) = 71.3kWh ("70" car) 84s * 64p = 5376 cells * (3100mah * 3.65v) = 60.8kWh ("60" car and software limited "40")