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Discussion Starter · #1 · (Edited)
Hello Folks,

I own a 2013 Chevy Volt Premier. Have owned it since 2015, and it only has abou 45,000 miles on the odometer.

Always used the 120V Level 1 charger that came along with the vehicle. But recently I installed 32 Amps Level 2 Charger in my garage and, as expected, it charges the Volt much faster than the one that came with the vehicle, but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that internally does the conversion from AC to DC) or is the new charger defective?
 

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Hello Folks,

I own a 2013 Chevy Volt Premier. Have owned it since 2015, and it only has abou 45,000 miles on the odometer.

Always used the 120V Level 1 charger that came along with the vehicle. But recently I installed 32 Amps Level 2 Charger in my garage, and as expected it charges the Volt much faster than the one that came with the vehicle, but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that does the conversion from AC to DC) or is the new charger defective?
2013 Volt has a 3.3kW on board charger. Most Residential line voltage is actually about 246V
246 V x 13.2 A = 3,247. W. Or (3.25 kW) so thats about right if factor some line loss.

Your L2 unit can transfer up to 32A load but the vehicle onboard charger regulates the actual current to its maximum rating.


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The maximum amps the Volt can pull is 16 IIRC.
 
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The maximum amps the Volt can pull is 16 IIRC.
“Can” is the key. Not necessarily will. 246V x 16A = 3.94 kW. That’s way more than the 3.3 kW onboard charger will allow.

Commercial properties typically run 208V. 208V x 16 A = 3.32 kW.
Makes it plausible for 16A maximum rating.


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tk3000

That's why you charge an EV with an EVSE (electric vehicle service equipment) and a J1772 plug/cable. The EVSE is a device that for safety reasons negotiates a current and voltage that it has to offer, the the Volt asks "I need 16 amps at 240 volts" after negotiating and checking for ground faults (E.G plug under water) 32a EVSE then turns on the "juice". That's why you can't just plug an EV onboard charger into any old power source directly like a golf cart charger. The protocol used by the EVSE to talk to an EV car is the ISO 15118 Protocol explained in the link below.


The EVSE only asks the car what it needs and if it can do that it will provide the power limited up to it's maximum current (protocol negotiation advertisement) and used by the onboard EV charging system. So with a Volt and a 32 amp EVSE the Volt will only draw 16 amps after the Volt "told" EVSE what it's requesting (16a). 32 amps would still be available but only 16 amps will be drawn by the Volt. If an EV said "I need 40 amps at 240" lets say, the 32a EVSE would reply "I only can do 32 amps" and not turn on to prevent blowing fuses, burning it's wiring, etc. The EV would reply "OK I'll only draw 32 amps can you send power?" the EVSE would reply "yes, turning power on now" example EV would then limit its draw to only 32 amps while charging. I might have the semantics wrong, an engineer on this forum can correct me, but you get the point I hope. The 120v level one provided EVSE only maxes out at 12 amps, the Volt will only ask for 12 or 8 amps at 120 volts. GM and all EV manufacturers engineers follow the SAE J1772-2017 standard which defines the levels of charging supported:


Charge methodVoltage, AC (V)PhaseMax. current,
continuous (A)
Branch circuit
breaker rating (A)[a]
Max. power (kW)
Charge methodEVSE DC output voltage (V)Max. current (A)Max. power (kW)
AC Level 11201-phase12 or 1615 or 201.44 or 1.92
AC Level 2208 or 2401-phase24–8030–1005.0–19.2
AC Level 3https://en.m.wikipedia.org/wiki/SAE_J1772#cite_note-27




Stephen

Hello Folks,

I own a 2013 Chevy Volt Premier. Have owned it since 2015, and it only has about 45,000 miles on the odometer.

Always used the 120V Level 1 charger that came along with the vehicle. But recently I installed 32 Amps Level 2 Charger in my garage and, as expected, it charges the Volt much faster than the one that came with the vehicle, but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that internally does the conversion from AC to DC) or is the new charger defective?
[/QUOTE]
 

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Always used the 120V Level 1 charger that came along with the vehicle. But recently I installed 32 Amps Level 2 Charger in my garage and, as expected, it charges the Volt much faster than the one that came with the vehicle, but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that internally does the conversion from AC to DC) or is the new charger defective?
As others have said, the amps are about right. My 2011 will pull 14 amps even though the EVSE is rated at 16A. 14x 240 ~= 3.3kW
 

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Discussion Starter · #7 ·
tk3000

That's why you charge an EV with an EVSE (electric vehicle service equipment) and a J1772 plug/cable. The EVSE is a device that for safety reasons negotiates a current and voltage that it has to offer, the the Volt asks "I need 16 amps at 240 volts" after negotiating and checking for ground faults (E.G plug under water) EVSE then turns on the "juice". That's why you can't just plug an EV onboard charger into any old power source directly like a golf cart. The protocol used by the EVSE to talk to an EV car is the ISO 15118 Protocol explained in the link below.


The EVSE only asks the car what it needs and if it can do that it will provide the power limited up to it's maximum current (advertised) and used by the onboard EV charging system. So with a Volt a 32 amp EVSE will only draw 16 amps after the Volt "told" it that's what it's requesting. 32 amps would still be available but only 16 amps will be drawn by the Volt. If an EV said "I need 40 amps at 240" lets say, the EVSE would reply "I only can do 32 amps" and not turn on to prevent blowing fuses, burning it's wiring, etc. The EV would reply "OK I'll only draw 32 amps can you send power?" the EVSE would reply "yes, turning power on now" example EV would then only draw up to 32 amps while charging. I might have the semantics wrong, an engineer on this forum can correct me, but you get the point I hope. The 120v level one provided EVSE only maxes out at 12 amps, the Volt will only ask for 12 or 8 amps at 120 volts for household wiring safety reasons.

Stephen

Hello Folks,

I own a 2013 Chevy Volt Premier. Have owned it since 2015, and it only has about 45,000 miles on the odometer.

Always used the 120V Level 1 charger that came along with the vehicle. But recently I installed 32 Amps Level 2 Charger in my garage and, as expected, it charges the Volt much faster than the one that came with the vehicle, but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that internally does the conversion from AC to DC) or is the new charger defective?
[/QUOTE]

Stephen,

I never really did work on my chevy volt (great and reliable car, shame on GM for having killed it). But I am somewhat familiar with the can bus due to have used in the past when working on an electric motorscooter that I had -- the vectrix.

It my understanding that the saej1772 plug and port have some pins dedicated to the data bus. Still, the firmware would have to be programmed, configured and setup based on the limitation of the Volt's internal charging module I would assume (given that I would imagine that such a small light weight charger would not be able to convert AC into high voltage DC)
 

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tk3000,

An EVSE is a safety device or a safety "on OFF" switch. It does not control amps or voltage, it only provides a "service" after the negotiation and safety parameters are met. Really its just a fancy outdoor "gate keeper" switch, a "relay with rules" so to speak. Only an expensive inverter/rectifier can make the regulated high voltage DC needed to charge an EV's traction battery.

Stephen

Stephen,

I never really did work on my chevy volt (great and reliable car, shave on GM for having killed it). But I am somewhat familiar with the can bus due to have used in the past when working on an electric motorscooter that I had -- the vectrix.

It my understanding that the saej1772 plug and port have some pins dedicated to the data bus. Still, the firmware would have to be programmed, configured and setup based on the limitation of the Volt's internal charging module I would assume (given that I would imagine that such a small light weight charger would not be able to convert AC into high voltage DC)
[/QUOTE]
 

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I have a Duosida rated for 16 amps. The most I’ve ever seen my 2015 Volt pull is 14.3 amps at 246 volts. It fully charges the Volt in 3 hours 20 minutes.
 

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At 'perfect' nominal 240V, you'd expect your 3.3kW onboard charger to pull 13.75 amps (240*13.75=3300). If you're seeing a little less, it's likely your voltage is slightly higher so the current is slightly reduced to stay within 3.3kW. Sounds normal to me.
 

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Hello Folks,

I own a 2013 Chevy Volt Premier. Have owned it since 2015, and it only has about 45,000 miles on the odometer.

Always used the 120V Level 1 charger that came along with the vehicle. But recently I installed 32 Amps Level 2 Charger in my garage and, as expected, it charges the Volt much faster than the one that came with the vehicle, but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that internally does the conversion from AC to DC) or is the new charger defective?
It may be 13.2Amps, but that is one each of the "legs". I kick myself for taking 4 years to install mine. My 2014 went from needing 9 hours (at "High") to 3.5 hours. Using 110v at High pulled over 16amps 110V and burnt up my GFI outlet. The 220V receptacle doesn't even get warm. Total Kilowatts are less too.
 

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It may be 13.2Amps, but that is one each of the "legs". I kick myself for taking 4 years to install mine. My 2014 went from needing 9 hours (at "High") to 3.5 hours. Using 110v at High pulled over 16amps 110V and burnt up my GFI outlet. The 220V receptacle doesn't even get warm. Total Kilowatts are less too.
Volts can only pull 12 amps max at 120V, never 16. Or are you talking about using some sort of quick220 device? I don't believe OP is talking about anything like that.
 

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It may be 13.2Amps, but that is one each of the "legs". … Using 110v at High pulled over 16amps 110V and burnt up my GFI outlet.
I know the math comes out the same, but that’s not what’s happening. The neutral isn’t wired into a level-2 EVSE. There aren’t two legs sending current to a neutral. The current going into one side is just coming out the other side (opposite phase). It really is 13.x amps at 240+ volts and not twice 13.x at 120v.

And if your EVSE & car was pulling more than 12-amps from a 120v circuit, something was broken. It should never do that.

Barry
 

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… but it seems to only feed up to 13.2Amps to the Volt. Is that a limitation of the Chevy Volt itself (that internally does the conversion from AC to DC) or is the new charger defective?
I’m going to kinda disagree with everyone else. I don’t think 13.2 is normal unless your voltage is very high. So first we need to know the voltage. Second, we don’t need to trust that 13.2 number as gospel. Are you reading it off the EVSE screen? Put a real amp meter (and volt meter) on it. If you have an OBD adapter, read out what the car sees as the input voltage and current. You should be seeing about 20% more than 3300 watts going in.
Barry
 

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I know the math comes out the same, but that’s not what’s happening. The neutral isn’t wired into a level-2 EVSE. There aren’t two legs sending current to a neutral. The current going into one side is just coming out the other side (opposite phase). It really is 13.x amps at 240+ volts and not twice 13.x at 120v.
Correct about the neutral and the current, but not quite right... There is only a single phase in residential service, so the current is not coming out the other side phase (opposite phase). The transformer winding feeding the service at a house has a grounded center tap that splits the 240V. The two hots coming into the house are the same phase, but current is flowing in opposite directions at any instant in time.
 

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I’m going to kinda disagree with everyone else. I don’t think 13.2 is normal unless your voltage is very high. So first we need to know the voltage. Second, we don’t need to trust that 13.2 number as gospel. Are you reading it off the EVSE screen? Put a real amp meter (and volt meter) on it. If you have an OBD adapter, read out what the car sees as the input voltage and current. You should be seeing about 20% more than 3300 watts going in.
Barry
I have a WiFi enabled digital meter on my EVSE. This is a typical reading while charging:

Product Orange Font Screenshot Material property
 
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Correct about the neutral and the current, but not quite right... There is only a single phase in residential service, so the current is not coming out the other side phase (opposite phase). The transformer winding feeding the service at a house has a grounded center tap that splits the 240V. The two hots coming into the house are the same phase, but current is flowing in opposite directions at any instant in time.
We’re using the word “phase” in different ways. I know what you’re saying. When I look at current on an oscilloscope and one signal has its peak of amplitude when the other signal has its valley, those two signals are “out of phase”. Enginerring speak vs electrician speak.


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