Great job Kyle! I find it hard to explain that the BMS can only estimate SOC, it cannot report “actual SOC.” Most people, even engineers, don’t seem to grasp the concept. I will be interested to see how you get voltage and current measurements to measure phantom drain. Are you going to have a special jumper HV harness made that will allow you to tap in to the HV circuit? Will you use a shunt to get maximum accuracy for Coulomb counting? I think it also will be necessary to measure 12 V drain, since anything taken from the 12 V battery will have to be replenished from the HV battery.
Your fuel gauge in an ICE car is also just an "estimate". If the fuel tank gets filled with dirt or gets a dent, it will also misread if it shows the contents as "Gallons / Liters", which may be why "E" and "F" are used. And the "estimated range" of ICE cars on remaining fuel is only an estimate. I don't see why many people are so upset about not getting the 100% correct number. They've never had it before, so what's the problem. Just the desire to complain because you can? And yes, you have to consider the 12V recharging from HV, as it is a known comsumption and the other things often runs on 12V.
17:01 Not only powering other systems. Also internal loss of the cells and also loss on the pack level (BMS by ballancing looses energy and also consumes energy).
The Outlander PHEV I had used to recharge its 12V battery once per day from its driving battery, at 2PM. It was slowly beeping while doing it. I imagine this is because the onboard electronics drain some juice out of it permanently and if not regularly recharged, it would drop too low. Imagine: on a BEV, the onboard computer works on 12V and needs to be working out of this same 12V power source to start this, again, same power source's recharge process. An electric car with a huge 400V battery can be incapacitated if its 12V battery fails!
Kyle, I'll be very interested in seeing your 'Phantom Drain' test on your Rivian. I've heard folks complain that it varies from 3-4 Kwh per day which seems pretty excessive.
I'd like to hear more about best practices for home charging and battery maintenance. BMS calibration, charging to 100%, off peak charging practices, etc. And Level 1 charging practices, for those of us that don't have access to at home level 2.
Two ways on measuring current: Having the electrons pass thru a meter that is now part of the current path and the second is a clamp that attempts to measure current passing through its hoop that is clamped around the wire. Being in the electron path typically is limited to 10A internal fuse of the meter but dead accurate. Not as familiar with clamps but looping the wire through the clamp becomes a multiplier to more accurately measure smaller amounts of current I suspect would be found in phantom drain. Doing either is going to be a challenge if not dangerous. 💯 charging your Rivian in your garage three days in a row with little to no driving it and then letting it go three days (or more) to see what drains is the easiest. You should be able to slow (AC) charge the Rivian with reduced current setting on the EVSE (or Rivian) to 💯SOC with a clamp meter on the charge cable going in. Shouldn’t have much heat losses and the top balanced pack should stop charging when truly at 💯 with almost zero losses due to the AC to DC conversion. The truck may even give an accurate charge added at this point but AC measured at the cable going in should tell you hold much power VxI=W was added (again without much in way of losses). Test the clamp meter on the EVSE charge cable attached to the truck not the AC from the wall to make sure you can pick up an accurate reading when adding current. Good luck.
I love you two, you are simply precious. And really, Phantom Drain (PD) is not quite understandable as: The lost energy in the battery minus (loss caused by chemistry and known consumption), both parts are things that can be explained and calculated. For pure theory, a battery that is left with a certain amount of energy, at a given temperature, will still have that same amount of energy when measured at the same temperature, regardless of whether the battery has been warmer or colder in the meantime. But even here, a very minimal loss may occur, solely due to the temperature change in the batterychemestry. And therefore, I think, PD is the loss that is described here as the decrease in energy that is NOT recognized as used and as we know is lost in chemistry (we know that a battery loses energy over time - this also applies to Alkaline batteries, for example). My claim is therefore that what is lost in chemistry and what is lost by real consumption (sentry mode, leaving the light on, having an OBD dongle plugged in) is NOT Phantom Drain, because it is logical to explain it as a chemical process and / or a physical drain of energy, since we consume via one or the other - so no traces of a "Phantom" about it. Best regards from Denmark
Before you talked about BMS sway your dad was correct. There is no actual energy loss in the pack, its just the environmental conditions will cause the released energy to only be a usable 75% when really cold. Look at lithium discharge charts that do several different temps on one graph. You'll see 0 to 45 Celsius all stay semi similar but -20 C is a huge dip in usable capacity or capacity discharged.
Battery gets colder, voltage drops, bms guesses lower. Tesla does show it as blue if the battery gets to I think 40f but you could be parking it with a quite warm battery after charging or a long drive and still get an almost 40f drop overnight before it would show blue. Also, when the battery is cold it has more internal resistance so when you drive with a cold battery it’s not as efficient.
Hey Kyle I have a new Model 3 with the LFP battery pack. I have been charging like Tesla says to 100%. Does the BMS calibrate everytime I charge that high? I have been watching ev video's so long now I feel like I'm hurting the battery going so high. But with new tech comes new charging requirements. But still there is doubt in my head.
Charge to 80-90% most days of the week and charge to 100% once a week (or every few days). The cool thing about LFP batteries is that they actually like their packs to be at higher state of charge compared to the older Li-ion (NCA) packs. > Does the BMS calibrate everytime I charge that high? Your BMS is calibrating all the time! The reality is that you don't need to worry about this too often. Just remember that in the winter you use more energy heating up battery pack and car, so you won't get full charge as rated in mild-hot conditions.
I can’t remember the exact number but I think some people were charging to 98% or just leaving a little bit of free space so that you still have that little bit of room left to get energy from regen breaking. Although I have no idea about battery health, so the point of the person above where you could charge to 100% every now and then could perhaps be a way of doing both, if regen isn’t getting you to 100% often enough.
There is a paper out there that investigates the possibility of memory effect for LiFeP04. That might be part of it. Life cycle # is so high that you won't ever kill the pack from cycle degradation
Current Transformers (not "Current Clamps") would allow you to measure Parasitic drain/draw (there are no Phantoms in science) roughly defined as the amount of current flowing from the battery when the vehicle is in the "Off" state. With EVs, there is going to be a redefinition of "Off" or there will never be an agreement on how many amps/milliamps are within specification in the "Off" state.
Do only Tesla’s have “Vampire Drain,” and other cars have “Phantom Drain?” 😀. By the way, the original Tesla Roadster had so much “Vampire Drain” that there was a blog post [since taken down] that it was equivalent to the power draw of “two very nice refrigerators.”
My question is why is it that it seems that almost all of this phantom drain comes from Tesla and Rivian, and not other EV’s? It seems like vehicles with traditional power buttons don’t seem to see any of this phantom drain?
I don't believe a Tesla needs to reach 100 percent or actually 100 percent for the BMS to activate cell balancing. Idk what voltage Tesla programmed for the trigger to activate cell balancing but maybe its 3.95 volts per cell for a guess!
"Here's Why You're Overthinking the EV Phantom/Vampire Drain Issue, Kyle"....This is a relative comparison of EVs, so factors such as changes in temperature effect for all of them... Rationalizing Teslas and Rivians, power hungry central processing methodology nature, (as due to a non ICE past) doesn't help their owners... Central processing has pros and cons and power usage is a definite con...
The Father Son Duo are Back. Great content. Great Podcast. Great Family. Thanks
Great job Kyle! I find it hard to explain that the BMS can only estimate SOC, it cannot report “actual SOC.” Most people, even engineers, don’t seem to grasp the concept. I will be interested to see how you get voltage and current measurements to measure phantom drain. Are you going to have a special jumper HV harness made that will allow you to tap in to the HV circuit? Will you use a shunt to get maximum accuracy for Coulomb counting? I think it also will be necessary to measure 12 V drain, since anything taken from the 12 V battery will have to be replenished from the HV battery.
Your fuel gauge in an ICE car is also just an "estimate". If the fuel tank gets filled with dirt or gets a dent, it will also misread if it shows the contents as "Gallons / Liters", which may be why "E" and "F" are used. And the "estimated range" of ICE cars on remaining fuel is only an estimate. I don't see why many people are so upset about not getting the 100% correct number. They've never had it before, so what's the problem. Just the desire to complain because you can?
And yes, you have to consider the 12V recharging from HV, as it is a known comsumption and the other things often runs on 12V.
17:01 Not only powering other systems. Also internal loss of the cells and also loss on the pack level (BMS by ballancing looses energy and also consumes energy).
Yo Dave when is the album dropping 🤣
MC BMS Sway 😂
The Outlander PHEV I had used to recharge its 12V battery once per day from its driving battery, at 2PM. It was slowly beeping while doing it. I imagine this is because the onboard electronics drain some juice out of it permanently and if not regularly recharged, it would drop too low. Imagine: on a BEV, the onboard computer works on 12V and needs to be working out of this same 12V power source to start this, again, same power source's recharge process. An electric car with a huge 400V battery can be incapacitated if its 12V battery fails!
Dave dropping some science on us. We weren't ready.
Kyle, I'll be very interested in seeing your 'Phantom Drain' test on your Rivian. I've heard folks complain that it varies from 3-4 Kwh per day which seems pretty excessive.
I'd like to hear more about best practices for home charging and battery maintenance. BMS calibration, charging to 100%, off peak charging practices, etc. And Level 1 charging practices, for those of us that don't have access to at home level 2.
Two ways on measuring current: Having the electrons pass thru a meter that is now part of the current path and the second is a clamp that attempts to measure current passing through its hoop that is clamped around the wire. Being in the electron path typically is limited to 10A internal fuse of the meter but dead accurate. Not as familiar with clamps but looping the wire through the clamp becomes a multiplier to more accurately measure smaller amounts of current I suspect would be found in phantom drain. Doing either is going to be a challenge if not dangerous. 💯 charging your Rivian in your garage three days in a row with little to no driving it and then letting it go three days (or more) to see what drains is the easiest. You should be able to slow (AC) charge the Rivian with reduced current setting on the EVSE (or Rivian) to 💯SOC with a clamp meter on the charge cable going in. Shouldn’t have much heat losses and the top balanced pack should stop charging when truly at 💯 with almost zero losses due to the AC to DC conversion. The truck may even give an accurate charge added at this point but AC measured at the cable going in should tell you hold much power VxI=W was added (again without much in way of losses). Test the clamp meter on the EVSE charge cable attached to the truck not the AC from the wall to make sure you can pick up an accurate reading when adding current. Good luck.
I love you two, you are simply precious.
And really, Phantom Drain (PD) is not quite understandable as:
The lost energy in the battery minus (loss caused by chemistry and known consumption), both parts are things that can be explained and calculated.
For pure theory, a battery that is left with a certain amount of energy, at a given temperature, will still have that same amount of energy when measured at the same temperature, regardless of whether the battery has been warmer or colder in the meantime. But even here, a very minimal loss may occur, solely due to the temperature change in the batterychemestry. And therefore, I think, PD is the loss that is described here as the decrease in energy that is NOT recognized as used and as we know is lost in chemistry (we know that a battery loses energy over time - this also applies to Alkaline batteries, for example). My claim is therefore that what is lost in chemistry and what is lost by real consumption (sentry mode, leaving the light on, having an OBD dongle plugged in) is NOT Phantom Drain, because it is logical to explain it as a chemical process and / or a physical drain of energy, since we consume via one or the other - so no traces of a "Phantom" about it.
Best regards from Denmark
Before you talked about BMS sway your dad was correct. There is no actual energy loss in the pack, its just the environmental conditions will cause the released energy to only be a usable 75% when really cold. Look at lithium discharge charts that do several different temps on one graph. You'll see 0 to 45 Celsius all stay semi similar but -20 C is a huge dip in usable capacity or capacity discharged.
Battery gets colder, voltage drops, bms guesses lower. Tesla does show it as blue if the battery gets to I think 40f but you could be parking it with a quite warm battery after charging or a long drive and still get an almost 40f drop overnight before it would show blue.
Also, when the battery is cold it has more internal resistance so when you drive with a cold battery it’s not as efficient.
Hey Kyle I have a new Model 3 with the LFP battery pack. I have been charging like Tesla says to 100%. Does the BMS calibrate everytime I charge that high? I have been watching ev video's so long now I feel like I'm hurting the battery going so high. But with new tech comes new charging requirements. But still there is doubt in my head.
Charge to 80-90% most days of the week and charge to 100% once a week (or every few days). The cool thing about LFP batteries is that they actually like their packs to be at higher state of charge compared to the older Li-ion (NCA) packs.
> Does the BMS calibrate everytime I charge that high?
Your BMS is calibrating all the time! The reality is that you don't need to worry about this too often. Just remember that in the winter you use more energy heating up battery pack and car, so you won't get full charge as rated in mild-hot conditions.
I can’t remember the exact number but I think some people were charging to 98% or just leaving a little bit of free space so that you still have that little bit of room left to get energy from regen breaking. Although I have no idea about battery health, so the point of the person above where you could charge to 100% every now and then could perhaps be a way of doing both, if regen isn’t getting you to 100% often enough.
There is a paper out there that investigates the possibility of memory effect for LiFeP04. That might be part of it.
Life cycle # is so high that you won't ever kill the pack from cycle degradation
If it is random sway would the error would it not be higher half the time - but it always seems to be lowere
What’s the update with the Rivian?
Current Transformers (not "Current Clamps") would allow you to measure Parasitic drain/draw (there are no Phantoms in science) roughly defined as the amount of current flowing from the battery when the vehicle is in the "Off" state. With EVs, there is going to be a redefinition of "Off" or there will never be an agreement on how many amps/milliamps are within specification in the "Off" state.
Have you received the current clamps to run the test?
I’m very interested in seeing your test results, if you’re really going to do this test?
I noticed with Tesla's if you don't adjust the climate control so it turns on automatically it will increase battery.
Do only Tesla’s have “Vampire Drain,” and other cars have “Phantom Drain?” 😀. By the way, the original Tesla Roadster had so much “Vampire Drain” that there was a blog post [since taken down] that it was equivalent to the power draw of “two very nice refrigerators.”
My question is why is it that it seems that almost all of this phantom drain comes from Tesla and Rivian, and not other EV’s? It seems like vehicles with traditional power buttons don’t seem to see any of this phantom drain?
Teslas and Rivians, power hungry central processing methodology nature,... Central processing has pros and cons and power usage is a definite con...
I don't believe a Tesla needs to reach 100 percent or actually 100 percent for the BMS to activate cell balancing. Idk what voltage Tesla programmed for the trigger to activate cell balancing but maybe its 3.95 volts per cell for a guess!
When the vehicle is parked
I really do not care about the name. What bothers me is that the effective range is falling from the promised EPA to around 55-65% of it (Tesla YLR)!
Drain
"Here's Why You're Overthinking the EV Phantom/Vampire Drain Issue, Kyle"....This is a relative comparison of EVs, so factors such as changes in temperature effect for all of them...
Rationalizing Teslas and Rivians, power hungry central processing methodology nature, (as due to a non ICE past) doesn't help their owners... Central processing has pros and cons and power usage is a definite con...