With the car indicating 40/40 amps I am only getting 32 mi/hr, not the 37 indicated on Tesla's Chart. My wall connector at home delivers exactly what the chart says. I also saw a YouTube video where the car got lower than expected mi/hr for the amperage drawn when connected to a public EVSE using the adapter. Does anyone know why that is? It seams to deify science. If you have the same volts and amps with the wall connector and J1772 you have the same power coming in. So where the rest go: nothing is hot.
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Low Mi/hr charge rate on j1772 with adapter
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How many volts are being delivered? It might be that the J1772 is on 208v (typical of US commercial installations) instead of 240v (typical of US residential installations).
eprosenx
Active Member
Yup. Exactly what @brkaus and @cwerdna said. Not only might it be a 208v feed, but often public J1772 units are a long way from a building so the voltage drop is high. It is not uncommon to only see 200v... (or even if a 240v feed, it could be making it to the car a lot lower)
But also, if your battery is cold or nearing its capacity, the charge rate will slow down (you will see actual amps drawn drop in that case).
So yeah, most likely a voltage thing.
I wonder if also your cabin is needing to be heated/cooled if this obviously takes away power that would otherwise be going into the battery...
I do not think it is voltage, more likely the car is using too much power.
Voltage has ranged 215-226 on different days but the mi/hr is always 32. The chart does indicate 240v but at home by TWC is feed 230v and the car charges at the cart indicated rates. The difference between 226 and 230 would only account for 1 less mi/hr. (36 vs. 37) The difference between 226 and 240 would account for a little over 2 mi/hr (34.8 vs. 37).
SOC has gone from 30% to 60%: it is not near full.
I am wondering if there is something about being connected through the adapter or just something different with a J1772 EVSE that prevents the car from powering down to the same degree as when connected to a Tesla EVSE and the car is somehow consuming the extra power.
Moments ago, the cabin temp was 98 F, so getting close the max and that could take some power when cooling kicks in. However, when I arrived at work the cabin would have been 72 or wherever I had it set and the charge rate has not changed. I remotely started cooling and the rate dropped to 28. Then when the cabin temp got to set point the rate went up to 29 mi/hr. Then I turned off climate control and it went back to 32. So am not sure heat/cooing is the cause but I am not ready to rule it out.
While it is not going to change my world it would be nice to have the extra 5 mi/hr if it can be fixed or at least understand the cause.
Voltage has ranged 215-226 on different days but the mi/hr is always 32. The chart does indicate 240v but at home by TWC is feed 230v and the car charges at the cart indicated rates. The difference between 226 and 230 would only account for 1 less mi/hr. (36 vs. 37) The difference between 226 and 240 would account for a little over 2 mi/hr (34.8 vs. 37).
SOC has gone from 30% to 60%: it is not near full.
I am wondering if there is something about being connected through the adapter or just something different with a J1772 EVSE that prevents the car from powering down to the same degree as when connected to a Tesla EVSE and the car is somehow consuming the extra power.
Moments ago, the cabin temp was 98 F, so getting close the max and that could take some power when cooling kicks in. However, when I arrived at work the cabin would have been 72 or wherever I had it set and the charge rate has not changed. I remotely started cooling and the rate dropped to 28. Then when the cabin temp got to set point the rate went up to 29 mi/hr. Then I turned off climate control and it went back to 32. So am not sure heat/cooing is the cause but I am not ready to rule it out.
While it is not going to change my world it would be nice to have the extra 5 mi/hr if it can be fixed or at least understand the cause.
In each case, have a look at the exact voltage once it has been pulling 40a for a few minutes.
I like to also look at the voltage right when it starts charging and the current is 1a.
I don’t know how your home would be fed by 230v unless the power company has a problem or your at the end of a very long line. I guess technically it’s in in range, but I don’t see that around here. I’m a actually at the high side - I frequently see 245v
I like to also look at the voltage right when it starts charging and the current is 1a.
I don’t know how your home would be fed by 230v unless the power company has a problem or your at the end of a very long line. I guess technically it’s in in range, but I don’t see that around here. I’m a actually at the high side - I frequently see 245v
tschmidty
Member
There is climate control for the battery as well, but in any case 215 compared to 240 would be 33.1 mph so not really all that far off. Cooling the battery since you just drove *might* explain it, but not likely since I haven't seen that. But in any case we are talking about 1-4 miles an hour maximum difference, so I wouldn't worry about it. Especially since you probably don't pay for it at work!
No, 215-225 has been the voltage range of at work. Indicated amperage and mi/hr are always 40/40 and 32 regardless.
It is a heavily industrial area with lots of large loads, both inside the facility and in the surrounding area. 225 was seen over the weekend when things were quiet. Today, with heavier loads it has been 215-217 at the car. The branch circuit to the EVSE has about a 2 volt drop between charging and not.
eprosenx
Active Member
Not germane to your issue, but now I am curious if that is a really hot 208v feed, or a really lousy 240v feed.
Amps times volts gives you watts, so that should be what your car is getting (assuming the rectifiers in the car are close to power factor 1). Subtract from that fixed losses and derate for the charging efficiency and that is what the battery should be storing.
Some difference can be accounted for by the difference in total watts as described. But you are interested in knowing why the rated miles is so different...
Not germane to your issue, but now I am curious if that is a really hot 208v feed, or a really lousy 240v feed.
The sub-panel is feed from a 480/230v transformer that seems to be about 227 lightly loaded. Voltage drop is 5.3-6.5%.
eprosenx
Active Member
Hrm. Typically in the US you have 480/277v three phase and then that is stepped down to 208/120v three phase. So then your EVSE would normally get two of the three hot legs of the second step down so 208v nominal. You may just have a really hot output that is supposed to be 208v nominal?
Otherwise in residential and small commercial you have single phase “split phase” which is 240/120v. So nominal for an EVSE would be the two hots at 240.
208/120 is typically used for receptacles and lighting. 230v 3 phase is a common industrial voltage used for heavier loads like larger motors. When I said the transformer was 480/230 I meant it was as step down transformer (from 480 to 230, three phase). The EVSE is connected to two legs of the 230 three phase.
eprosenx
Active Member
Hrm, I am not aware of this voltage configuration. There is a configuration called "High-leg Delta" where each of the phases is 240v from each other (so used for three phase 240v motors), and then one of the phase pairs are center tapped to neutral which gives you the ability to have 120v from neutral to those two hot conductors. Then the third phase has 240v to each of the other phases, but 208v to the neutral. It is a voltage configuration that allows the power company to deliver three phase service with only two transformers and to provide both 120v and 240v and 240v three phase.
If this is the type of service your work has then the question is how did they hook up the EVSE? Generally you would not do a single phase breaker from the "high leg" (aka 208v leg) to neutral (the breakers are not very common for one thing). Then I know the Tesla Wall Connector says *not* to use the 240v phase pairs that are not center tapped. You are only supposed to use the center tapped pair of phases. I do not know if this applies to other EVSE's as well.
I wonder if this has something to do with your issue...
Also, 230v is not a thing here in the US as far as I know. As described above, nominal is 240v. Other common voltages are 120v, 208v, 277v, and 480v.
The issue I have seen with Level 2 chargers has been when they are controlled by the charging operators network to pause.
If the car is paused at the beginning when current is offered later, the Model 3 doesn't allow any juice to flow without the car being remote unlocked or unlocked with the Fob again.
Never seen this with Model 3 & Model X. Don't know why the charging software for the model 3 is different?
If the car is paused at the beginning when current is offered later, the Model 3 doesn't allow any juice to flow without the car being remote unlocked or unlocked with the Fob again.
Never seen this with Model 3 & Model X. Don't know why the charging software for the model 3 is different?
If 230v is not a thing here in the US then someone needs to inform NFPA so they can update the NEC.
230v three phase, (three wire, no neutral) is a thing and commonly used for motors. NEC Table 430.250 gives the full load current for standard motors. If you look at it you will see there are columns for both single and three phase 230v motors and there is no mention of a 240 nominal voltage. Most industrial motors I come across these days are set up for dual voltage. The high voltage on the name plate is 460 or 480 (one or the other). The low voltage is always given as a range of 208-230. If the feed is 208 then the panel would normally have a neutral because it is a 208/120 panel that could be used for 120v to neutral single phase circuits. If it is a 230v panel then there would not be a neutral and it would be intended for primarily motor loads were single-phase (2-pole, not line to neutral ) or 3-phase 230v line to line voltage is needed.
eprosenx
Active Member
If 230v is not a thing here in the US then someone needs to inform NFPA so they can update the NEC.
230v three phase, (three wire, no neutral) is a thing and commonly used for motors. NEC Table 430.250 gives the full load current for standard motors. If you look at it you will see there are columns for both single and three phase 230v motors and there is no mention of a 240 nominal voltage. Most industrial motors I come across these days are set up for dual voltage. The high voltage on the name plate is 460 or 480 (one or the other). The low voltage is always given as a range of 208-230. If the feed is 208 then the panel would normally have a neutral because it is a 208/120 panel that could be used for 120v to neutral single phase circuits. If it is a 230v panel then there would not be a neutral and it would be intended for primarily motor loads were single-phase (2-pole, not line to neutral ) or 3-phase 230v line to line voltage is needed.
So on motors you use a 230v motor on a 240v system. The logic is that 240v is nominally what would be delivered by the provider, but they figure some loss from the main delivery point to be motor, so they plan for a slightly lower voltage as the target voltage for the motor (but they can operate in a pretty wide range).
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