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Is this normal?
- Thread starter braoudap
- Start date
Unless you have some tools to tell you what the battery temperature is, "50 degrees and sunny" doesnt mean your battery is warm enough to take full speed charging, so battery temp is still in play as the root cause, and is the likely answer.
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Um. I have a Model 3, which is similar to a Model Y. Both of those cars have, for lack of a better term, "modules". Each module can rectify 16A of Level 2 charging. Note: This is AC to DC rectification, not supercharging.
Having said that, there were a number of cases recently where owners of older versions of the cars listed above had kaput modules. So, a MY LR with three modules that could rectify 48A worth of 240 VAC might only do, max, 32A. Or 16A. And there was some foo-fer-ah with Tesla about whether the faulty modules would be repaired under warranty or not. So, this kind of thing is not unheard of. And, yeah, L2 charging is definitely not Supercharging, so YMMV.
So, a Model S that, instead of being able to do however many kW a SC could supply is now doing 24 kW? I'm thinking Car Fault. Or something in the Protocol (kind of like saying, "Something in the Force") is fouled up. Maybe in the switch to CCS charging?
Is this true at all SC's, or just this one? If it's just this one, with all its stalls, I'm betting software bug. If it's at all SCs far and wide, I'm thinking a busted tranny or circuit board somewhere in the car.
Having said that, there were a number of cases recently where owners of older versions of the cars listed above had kaput modules. So, a MY LR with three modules that could rectify 48A worth of 240 VAC might only do, max, 32A. Or 16A. And there was some foo-fer-ah with Tesla about whether the faulty modules would be repaired under warranty or not. So, this kind of thing is not unheard of. And, yeah, L2 charging is definitely not Supercharging, so YMMV.
So, a Model S that, instead of being able to do however many kW a SC could supply is now doing 24 kW? I'm thinking Car Fault. Or something in the Protocol (kind of like saying, "Something in the Force") is fouled up. Maybe in the switch to CCS charging?
Is this true at all SC's, or just this one? If it's just this one, with all its stalls, I'm betting software bug. If it's at all SCs far and wide, I'm thinking a busted tranny or circuit board somewhere in the car.
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I second @jjrandorin and will say cold battery. Model S has a dedicated battery heater that sometimes goes bad. I don't know if model S indicates that it heats the battery on screen. Did you navigate to the supercharger, and for how long?
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smogne41
Active Member
The modules don't do the rectification, that is the job of the onboard charger. There is one onboard charger that accepts AC and produces DC. It is commanded by the BMS to supply the proper voltage so the pack will draw the correct current given all the conditions the BMS monitors (SOC, cell group health, temperature, etc). DC fast charging works in a similar way, except the onboard charger is bypassed and the BMS just asks the DC fast charger station for the voltage it wants and DC is connected directly to the pack cells.
But yes, faults in the car can absolutely lower the rate for either AC or DC charging. But if the car is working correctly, the two biggest factors are pack temperature and current SOC.
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You misunderstood what @Tronguy said. He was referring to the onboard charger, but was mentioning how internal to that, the charger is made up of multiple parts. There isn't a very consistent word that is used for those parts, so "modules" or "boards" or something else are sometimes terms that are used. Still, it was all rather irrelevant to talk about the onboard charger when this is an issue with Supercharger speed.
First thought is that it's probably cold, but second thought is that I still haven't seen what the state of charge was either, which could be another part of it.
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I did not navigate to the SC as it’s in my neighborhood. But trust me, I’ve charged in way colder conditions than this. I’ve never seen pathetic numbers like this.
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Then it had no time to warm up at all and makes it much more likely that it was cold.
? It's the battery meter--like the fuel gauge. It shows either some number of rated miles or some percentage, depending on which unit you have selected in your settings.
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Good question, simple answer: Tap the icon that shows how many miles you got; it changes to a percent symbol with a number.
The closer one is to full charge, the slower the battery will charge.
So, for a random example:
- One is at 90% of full charge
- It's 0F out there. Brr!
- The battery heater is out to lunch or the car's been Just Sitting There, freezing
Interestingly, if one is using a Wall Connector (i.e., L2, 240 VAC charging) and one is prepping for a trip, then charging to 100% is an OK thing to do. But the charge rate at 98% or thereabouts gets really, really small, like 1 kW or something. Note that on a M3 (yes, I know, you got a Model S) that normally can chug along at 11 kW up to 90% charge falls off at 98% or some such. And... So does a Supercharger. A Supercharger trying to charge a battery to 100% falls to the same 1 kW numbers that a L2 charger does.
Now, show up at a Supercharger with 3% State of Charge on a warm day: That's when one discovers (at least, on a M3, anyway) that said Supercharger can whoompf 250 kW into the battery. That keeps on until one gets to 30% state of charge, at which point the rate starts falling off; at around 90%, it's 30 kW or something and keeps on going down.
The charging system, as others have noted repetitively, restricts the charging rate when the battery is cold. This is why Tesla likes people to navigate to an SC; when the car sees that one is doing that, it dissipates a ton of heat into the battery, warming it up so it'll charge faster when it Gets There. On the older Teslas, this was done by purposely dumping excessive current into the motor so the cooling fluid would get warm and heat the battery; the newer ones use the heat pump (and maybe the motor) for the same purpose.
Thing is: Even with all that, 24 kW with 120 miles on the gauge (maybe 50% SOC?) is a bit on the low side. Even if it is cold out there. In my experience, anything warmer than 45F or so isn't all that cold. And, yeah, I live in NJ and make trips to Boston, both places known for being much colder than 45F in the winter.
My suggestion: Run an experiment. Get the car down to 120 miles or so, then drive to an SC, or maybe two. If your charge rate is still 24 kW, it's probably a car issue. If, after running the car around the landscape a bit, the charge rate is more like 100 kW, then it might have been the SC. It's not clear, so a little troubleshooting like this might be in order.
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FWIW, I've found that I need to precondition the battery (navigate to charger) for at least 45 min to get ideal charging speeds.
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That's my thought, too. I've taken a M3 from Parking Lot A to Parking Lot B that had the SCs when it was 40F out and, while my charging rates were lower than normal, they were over 100 kW. That 24 kW charging rate sounds low to me, unless the battery was nearly full, and the OP indicated that it wasn't.
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