rcedwards
Posts: 3
Joined: Fri Jul 06, 2018 10:42 pm

Maximum Level 2 Charge Rate

Fri Jul 06, 2018 10:53 pm

Greetings

Long time Nissan LEAF driver. Taking a hard look at the Chevy Bolt.

I've often seen the charging specifications for the Bolt listed as 32A/240V, 7.2KW.

It seems to me that 32A X 240V is 7.7 KW, not 7.2KW. I realize that this is rather small, but it does add up for a 60KWH vehicle.

Any clarification from Bolt owners?

Thanks

DucRider
Posts: 597
Joined: Tue Feb 09, 2016 5:25 pm

Re: Maximum Level 2 Charge Rate

Sat Jul 07, 2018 5:23 am

From the application GM submitted to the EPA:
Electric Drive Unit
One 3-phase AC Permanent Magnet electric motor
150 kW 10 second peak Power
360 Nm peak torque
Battery
Lithium Ion battery pack
60 kWh pack energy capacity
7.6 kW On-Board; 50 kW Off-Board charge power


https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=38567&flag=1
Gary

2014 Honda Fit EV - lease ends Jan 2019

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paulgipe
Posts: 173
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Location: Bakersfield, California 93305
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Re: Maximum Level 2 Charge Rate

Sat Jul 07, 2018 1:23 pm

rcedwards wrote:Greetings

Long time Nissan LEAF driver. Taking a hard look at the Chevy Bolt.

I've often seen the charging specifications for the Bolt listed as 32A/240V, 7.2KW.

It seems to me that 32A X 240V is 7.7 KW, not 7.2KW. I realize that this is rather small, but it does add up for a 60KWH vehicle.

Any clarification from Bolt owners?

Thanks


I am using the same HSC 40 that I used with the Leaf. I haven't observed the Bolt drawing more than ~6.6 kW from this circuit. The car says "7" kW but that could mean 6.6, 7, 7.2, etc. My meter measures total household draw so I have to interpolate from other loads.

It hasn't been an issue. I typically charge overnight and from a low SOC to 100% or to Hill Top Reserve, an overnight charge is sufficient.

Could be my instruments. I haven't looked into it further.

Paul
Paul Gipe
2017 Bolt LT with DCFC, leased 11/09/17
2015 Nissan S with QC, leased, returned
2013 Chevy Volt Premium, used, sold
L2; ClipperCreek HCS-40; Jesla; JDapter Stub
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Zoomit
Posts: 294
Joined: Wed Jan 06, 2016 10:45 pm
Location: SoCal

Re: Maximum Level 2 Charge Rate

Sat Jul 07, 2018 7:01 pm

It'll do 7.7kW. Examples in archives on various forums
2017 Bolt EV LT
2018 Model 3 LRD

BillHowland
Posts: 25
Joined: Wed Nov 22, 2017 11:33 pm

Re: Maximum Level 2 Charge Rate

Wed Jul 18, 2018 12:55 pm

rcedwards wrote:Greetings

Long time Nissan LEAF driver. Taking a hard look at the Chevy Bolt.

I've often seen the charging specifications for the Bolt listed as 32A/240V, 7.2KW.

It seems to me that 32A X 240V is 7.7 KW, not 7.2KW. I realize that this is rather small, but it does add up for a 60KWH vehicle.

Any clarification from Bolt owners?

Thanks


Hi - Yeah I've had this question myself as the BOLT ev was listed in the advertising literature as 32 amperes, 7.2 kw. The GEN 1 VOLT and ELR were limited to 15 amperes, and apparently a hard 3.3 kw, since if you came in with more than 220 volts (e.g.: 240) the current would throttle down from 15. The time I rented a GEN 2 volt I confirmed the 16 amperes at lower voltages, but absent mindedly, forgot to check it during the time of day was much greater than 225. (The juice in my neighborhood is horrible during the summertime due to 5 separate issues of incompetence by the utility - National Grid - which I won't bore you with here).

But The BOLT ev seems different as if you come in with a high enough voltage, the current is limited to 32 amperes but the power level goes at least to 7.7 kw - the highest voltage (240) I could easily muster. (That horribly obtuse dashboard display occasionally flashes '8 kw').

Hope that answers your question.

Rwolf01
Posts: 1
Joined: Mon Sep 09, 2019 5:42 am

Re: Maximum Level 2 Charge Rate

Mon Sep 09, 2019 5:56 am

There is typically a hard current limit of 32 Amps. (but depending on the EVSE, the supply may assert a lower limit, which the car must obey)

But it will take whatever voltage it gets. You have little direct control over that. 240V is optimistic. That assumes limited upstream losses. At current, 230V is more typical. In an industrial location 208V is common (one branch of a 3-phase supply) which gets loaded dow to ~205V.

240V => 7.68kW
230V => 7.36kw
220V => 7.04kw
205V => 6.56kw

So I think they pick 7.2kw as a 'typical' input power.

Another possible explaination is that 7.2kw is the power delivered to the battery, after accounting for ~6% conversion losses in the on board charger.

Worry about the current, not the power. The car can take up to 32 Amps, so for fastest Level 2 charging make sure you are using a 40 Amp or larger breaker to feed a 32Amp or larger EVSE.

At home, you should look at the voltage losses in your home wiringing. The voltage at the EVSE will always be a little lower than at the power meter. A small drop is unavoidable, but if the voltage drop flucturates, or is higher on one leg of the 240V circuit than the other, you potentially have a wiring problem. At best, the voltage drop is costing you money because you are paying to heat your walls. At worst, that heat is concentrated at a bad connection somewhere and could start a fire)

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