Chargepoint 6.6kWh only reaching ~5.9kWh

[virpio]

Hi,

I recently switched from a Chevy Bolt to a Tesla Model 3. I am mostly charging my car at work where we have Chargepoint chargers. My Bolt was charging at these with the maximum 6.6kWh according to the Chargepoint app. With the Model 3 now I notice that the charge rate never exceeds ~5.9kWh. It is always slightly below 6kWh and is less steady then the charing of the Bolt.

I am wondering if others are able to achieve the full 6.6kWh charge rate at the Chargepoint chargers? What could cause the Model 3 to not charge at full speed?

—Michael

 

[coconutboy84]

Is your model 3 set to charge at at least 30 amps in the settings?

 

[Kirby64]

Hi,

I recently switched from a Chevy Bolt to a Tesla Model 3. I am mostly charging my car at work where we have Chargepoint chargers. My Bolt was charging at these with the maximum 6.6kWh according to the Chargepoint app. With the Model 3 now I notice that the charge rate never exceeds ~5.9kWh. It is always slightly below 6kWh and is less steady then the charing of the Bolt.

I am wondering if others are able to achieve the full 6.6kWh charge rate at the Chargepoint chargers? What could cause the Model 3 to not charge at full speed?

—Michael

First of all, it's kW, not kWh. kWh is capacity, kW is power.

What's the voltage of the Chargepoint charger as reported by the Tesla?

Most commercial Chargepoint chargers are off 3-phase power, so you only get like ~208 (less under load) power. If it's a 30 amp charger, you should get ~6.2kW max. In my experience, the load typically makes this voltage closer to 200V even. That means you get 6kW.

The only way to get 6.6kW would be to have 220V charging. Either 3-phase that's over it's typical voltage, or 240V split phase that's WAY under it's typical voltage.

My guess is the Bolt is reporting it weirdly. All of the Chargepoint stations I've seen report '6.6kW' for the '32 amp' capable chargers (16A for 2 cars, or 30A for 1 car, based on 208V voltage). Are you sure the Bolt is actually charging at 6.6kW? That would mean it's almost certainly pulling 32A. If the Bolt is lazy and just does 220 * current (i.e. 30), then that would get you to 6.6kW.

 

[srs5694]

The only way to get 6.6kW would be to have 220V charging. Either 3-phase that's over it's typical voltage, or 240V split phase that's WAY under it's typical voltage.

Well, 32A x 208v = 6.656kW, so there's that possibility; however, every ChargePoint Level 2 EVSE I've seen has delivered 30A, not 32A, so that seems unlikely -- but I wouldn't rule out the possibility entirely. 30A x 208v = 6.24kW; and 30A x 240v = 7.2kW.

I agree that the exact amperage and voltage reported by the Tesla would be useful diagnostic information. If nothing else, that should nail down the voltage, which shouldn't vary between the cars (although it might vary by a couple of volts between charging sessions, and even within a session).

My guess is the Bolt is reporting it weirdly.

@virpio said that it was ChargePoint's app that was reporting the Bolt as consuming 6.6kW, vs. 5.9kW for the Model 3. If it's ChargePoint making both claims, then it seems unlikely that it's either car reporting it incorrectly. My guess is it's either a reporting glitch on ChargePoint's part or a handshaking or connection problem pulling the amperage down slightly on the Model 3. 5.9kW / 208v = 28.4A; and 5.9kW / 240v = 24.6A, so a drop to 28A or 24A could account for the issue. The Model 3 will reduce the amperage of its connection if it detects a less-than-ideal connection, but I don't recall offhand by how much it drops the amperage. A poor connection could be a symptom of a degraded J1772 connector on the EVSE, a defective Tesla J1772 adapter, a defective plug on the Tesla, or not quite properly connecting the pieces. Testing with another EVSE and/or J1772 adapter might help trace the problem, if this is what's happening. Thus, I'd check the Tesla app (or dashboard display) to see the voltage and amperage it's reporting for comparison with the ChargePoint app, and also try another ChargePoint EVSE and check both what ChargePoint and the Tesla say when using it.

You might also ask other co-workers who use the EVSE if they've seen problems recently; it could be that the workplace dropped the amperage deliberately at the same time you switched cars, or that a fault has developed in the EVSE.

 

[SSedan]

ChargePoint are often a long ways from the power panel and in my experience suffer terrible voltage sag due to that.
Betting it is under 200volts under load.

 

[Kirby64]

Well, 32A x 208v = 6.656kW, so there's that possibility; however, every ChargePoint Level 2 EVSE I've seen has delivered 30A, not 32A, so that seems unlikely -- but I wouldn't rule out the possibility entirely. 30A x 208v = 6.24kW; and 30A x 240v = 7.2kW.

I agree that the exact amperage and voltage reported by the Tesla would be useful diagnostic information. If nothing else, that should nail down the voltage, which shouldn't vary between the cars (although it might vary by a couple of volts between charging sessions, and even within a session).



@virpio said that it was ChargePoint's app that was reporting the Bolt as consuming 6.6kW, vs. 5.9kW for the Model 3. If it's ChargePoint making both claims, then it seems unlikely that it's either car reporting it incorrectly. My guess is it's either a reporting glitch on ChargePoint's part or a handshaking or connection problem pulling the amperage down slightly on the Model 3. 5.9kW / 208v = 28.4A; and 5.9kW / 240v = 24.6A, so a drop to 28A or 24A could account for the issue. The Model 3 will reduce the amperage of its connection if it detects a less-than-ideal connection, but I don't recall offhand by how much it drops the amperage. A poor connection could be a symptom of a degraded J1772 connector on the EVSE, a defective Tesla J1772 adapter, a defective plug on the Tesla, or not quite properly connecting the pieces. Testing with another EVSE and/or J1772 adapter might help trace the problem, if this is what's happening. Thus, I'd check the Tesla app (or dashboard display) to see the voltage and amperage it's reporting for comparison with the ChargePoint app, and also try another ChargePoint EVSE and check both what ChargePoint and the Tesla say when using it.

You might also ask other co-workers who use the EVSE if they've seen problems recently; it could be that the workplace dropped the amperage deliberately at the same time you switched cars, or that a fault has developed in the EVSE.

If you read carefully the OP actually states that the Bolt (via chargepoint) was consuming 6.6kW, while he did not specify how he was measuring the Tesla consumption. My guess is this is Chargepoint reporting vs. Tesla App reporting.

Alternatively, it could be this: I've noticed the Chargepoint stations will sometimes provide 28A max (as reported by Tesla) when the other car connected it considered 'Done' charging. It'll limit the 'Done' car to 4A max, then give the rest to the high power car. 28A would be 5.8kW on the nose.

 

[yuhong]

I believe ChargePoint always display 6.6kW as a maximum regardless of the actual charging voltage. If you plug in your car, ChargePoint will display the actual value for a while after charging starts.

 

[virpio]

I totally get that this could vary depending the charger and even between the charger and what the car actually receives. That's why I mentioned that I see this in the Chargepoint app, on the same chargers. If the Chargepoint app shows wrong values I would at least expect it to show the same wrong values for all cars.

The Model 3 is showing ~200V and is set to 30A (I think I can't set it to 32A?), so that matches what Chargepoint is showing for the car. For the Bolt I don't have these infos because the Bolt wasn't displaying any of these values in car, to my knowledge, so for that I only have the Chargepoint value which was showing 6.6kW.

It's unlikely that the chargers are suddenly charging at a lower rate since it's a fairly new building with EV charging planned right form the beginning. I will check with my coworkers to see if they are also seeing Model 3 charging below 6kWh. I was just wondering if there is something obvious the Model 3 does that maybe a cheaper car like the Bolt wouldn't do.

 

[peakshaving]

I totally get that this could vary depending the charger and even between the charger and what the car actually receives. That's why I mentioned that I see this in the Chargepoint app, on the same chargers. If the Chargepoint app shows wrong values I would at least expect it to show the same wrong values for all cars.

The Model 3 is showing ~200V and is set to 30A (I think I can't set it to 32A?), so that matches what Chargepoint is showing for the car. For the Bolt I don't have these infos because the Bolt wasn't displaying any of these values in car, to my knowledge, so for that I only have the Chargepoint value which was showing 6.6kW.

It's unlikely that the chargers are suddenly charging at a lower rate since it's a fairly new building with EV charging planned right form the beginning. I will check with my coworkers to see if they are also seeing Model 3 charging below 6kWh. I was just wondering if there is something obvious the Model 3 does that maybe a cheaper car like the Bolt wouldn't do.

It sounds like your chargepoint chargers are using 208V (the 200 is from voltage drop because real world) You can't set it to 32A because Chargepoint only supports up to 30A. Your car supports 32A at least but since the charger won't/can't pump more than 30A, the handshake agrees on 30A and so that's as much as you'll get.
The chargepoint app always gives you the projected power assuming you have 240V on the station information. It's only on the display but it tracks your power usage properly (200v @30A) so it's not going to overcharge you, but you are going to be charging at 208V instead of 240V.

The Bolt's always assumed 240V IIRC. This was a year ago when I checked but I wouldn't be surprised if they never fixed it.

(I'm assuming you're using the same chargers I'm using which are CT4000 series Chargepoint chargers)

 

[virpio]

It sounds like your chargepoint chargers are using 208V (the 200 is from voltage drop because real world) You can't set it to 32A because Chargepoint only supports up to 30A. Your car supports 32A at least but since the charger won't/can't pump more than 30A, the handshake agrees on 30A and so that's as much as you'll get.
The chargepoint app always gives you the projected power assuming you have 240V on the station information. It's only on the display but it tracks your power usage properly (200v @30A) so it's not going to overcharge you, but you are going to be charging at 208V instead of 240V.

The Bolt's always assumed 240V IIRC. This was a year ago when I checked but I wouldn't be surprised if they never fixed it.

(I'm assuming you're using the same chargers I'm using which are CT4000 series Chargepoint chargers)

I still don't understand how the Chargepoint app would give me different values for both cars on the same charger though. If the Bolt assumes something different, how does that matter? The Chargepoint app should do the same no matter what car is connected? So the Bolt charging with a higher rate than the Model 3 seems to be a real thing?

 

[Big Earl]

30 amps a 200 volts is 6 kW.

ChargePoint will list stations as providing power at 240 volts even if the stations are connected to 208 volt power. The live consumption should be accurate, but the advertised speed will be higher than the station is capable of providing on the reduced voltage.

Conclusion: there is no problem with your Model 3.

 

[virpio]

30 amps a 200 volts is 6 kW.

ChargePoint will list stations as providing power at 240 volts even if the stations are connected to 208 volt power. The live consumption should be accurate, but the advertised speed will be higher than the station is capable of providing on the reduced voltage.

Conclusion: there is no problem with your Model 3.

I get that. That doesn't answer the question though. Unless you are saying the Chargepoint app is lying about the charge speed of a Bolt but gives me accurate values for a Model 3, which I would find highly doubtful.

 

[DickBlonov]

I totally get that this could vary depending the charger and even between the charger and what the car actually receives. That's why I mentioned that I see this in the Chargepoint app, on the same chargers. If the Chargepoint app shows wrong values I would at least expect it to show the same wrong values for all cars.

The Model 3 is showing ~200V and is set to 30A (I think I can't set it to 32A?), so that matches what Chargepoint is showing for the car. For the Bolt I don't have these infos because the Bolt wasn't displaying any of these values in car, to my knowledge, so for that I only have the Chargepoint value which was showing 6.6kW.

It's unlikely that the chargers are suddenly charging at a lower rate since it's a fairly new building with EV charging planned right form the beginning. I will check with my coworkers to see if they are also seeing Model 3 charging below 6kWh. I was just wondering if there is something obvious the Model 3 does that maybe a cheaper car like the Bolt wouldn't do.

The default setting is 32 or 48 depending on your model (SR or LR). Mine is set to 48, and charging is done at whatever the EVSE can supply.

Phil

 

[flyingowl]

Jesus Christ !!! What's next.... OMG My tesla only chargers 149KW on 150KW supercharger? .

 

[CrayZ1]

In commercial or industrial areas 240vac 1ph is really rare. Everything is 120vac, 277vac, 208vac 3ph, 480vac 3ph.
If he was getting ~5.9 out of a 6.6kW, that's the most likely cause.

 

[peakshaving]

I still don't understand how the Chargepoint app would give me different values for both cars on the same charger though. If the Bolt assumes something different, how does that matter? The Chargepoint app should do the same no matter what car is connected? So the Bolt charging with a higher rate than the Model 3 seems to be a real thing?

There's a page with a graph on chargepoint during an active session (and for previous session) that shows the live kW output to the car when charging.

It should say 6kW for both. I don't know where you're seeing higher rate on the Bolt vs the 3. Either way- There's nothing wrong with your Model 3. EVSEs literally just connect you to the grid. It's a wire with a bunch of power protection. They don't have the hardware to step down the voltage from 240 to 200. If Tesla is showing 6kW then it's 6kW. I would be suspicious of either car throttling power if the amperages were different but if it's the voltage that's different then there's no way the Bolt is the correct one.

Another thing you can do is just measure the kWh gained yourself. Check how much kWh you're adding on the Bolt vs 3 over 1 hr. You can even use the miles gained on the Model 3 to calculate that.

If you really want to get to the bottom of this- call chargepoint. They'll just tell you what the station's power configuration is and you'll know what the max power out of the station is.

 

[Kirby64]

FYI - to those saying that the ChargePoint app always pins the charging rate off of 240V: This is not true. Both my charging session graphs and the stations themselves report the proper power: 6.6kW 'shared' = 208V * 32A. Or 3.3kW/2 ports = 208V * 16A.

If they pinned charging rate at 240V, they would all say 7.2kW. It's possible that the owners of the stations may set them up improperly, perhaps? I imagine the voltage is something that they have to select when configuring the station online and it isn't auto detected, since it can vary a lot based on the load of a building.

 

[eladts]

FYI - to those saying that the ChargePoint app always pins the charging rate off of 240V: This is not true. Both my charging session graphs and the stations themselves report the proper power: 6.6kW 'shared' = 208V * 32A. Or 3.3kW/2 ports = 208V * 16A.

If they pinned charging rate at 240V, they would all say 7.2kW. It's possible that the owners of the stations may set them up improperly, perhaps? I imagine the voltage is something that they have to select when configuring the station online and it isn't auto detected, since it can vary a lot based on the load of a building.

The only problem with this calculation is that all the ChargePoint "6.6kW" station that I'm aware of are limited to 30A, not 32A. 30A * 208V = 6.2kW and 30A * 240V = 7.2kW. The only way you would get 6.6kW in those station is with 220V, which isn't a nominal voltage anywhere in the US.

 

[Kirby64]

The only problem with this calculation is that all the ChargePoint "6.6kW" station that I'm aware of are limited to 30A, not 32A. 30A * 208V = 6.2kW and 30A * 240V = 7.2kW. The only way you would get 6.6kW in those station is with 220V, which isn't a nominal voltage anywhere in the US.

That's because ChargePoint is dumb (or intentionally misleading) and specifies it as the max current based on the breaker that is backing it, it seems. The 40 amp backing breaker (i.e. 32A continuous) seems to be the most common I see around town.

Here's a common ChargePoint datasheet:
https://www.chargepoint.com/files/datasheets/ds-ct4000.pdf

The one at my work is the 'Standard Power Share' edition. It uses a single 40A input, and it can provide up to either 1x30A output or 2x16A outputs. Technically, if they actually provided the full amount you could pull 6.6kW out of one car. For whatever dumb reason their chargers limit the max current from one port to 30 amps, though. Even the 'Standard' ones that need 2 x 40A breakers only limit output to 30A per port.

Plenty of other vendors offer the full 32A output with a 40A input breaker, so I don't know what ChargePoint's issue is... a stupid safety margin perhaps?

 

[eladts]

That's because ChargePoint is dumb (or intentionally misleading) and specifies it as the max current based on the breaker that is backing it, it seems. The 40 amp backing breaker (i.e. 32A continuous) seems to be the most common I see around town.

Here's a common ChargePoint datasheet:
https://www.chargepoint.com/files/datasheets/ds-ct4000.pdf

The one at my work is the 'Standard Power Share' edition. It uses a single 40A input, and it can provide up to either 1x30A output or 2x16A outputs. Technically, if they actually provided the full amount you could pull 6.6kW out of one car. For whatever dumb reason their chargers limit the max current from one port to 30 amps, though. Even the 'Standard' ones that need 2 x 40A breakers only limit output to 30A per port.

Plenty of other vendors offer the full 32A output with a 40A input breaker, so I don't know what ChargePoint's issue is... a stupid safety margin perhaps?

What's even more weird is that their home charger does support 32A. They also have a new model that supports 50A on a 70A breaker.

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