Difference in installing a 32 or 40 amp level 2 charger?

Ride_the_lightning

Well-Known Member
Joined
Jul 11, 2021
Threads
6
Messages
545
Reaction score
1,067
Location
Midwest
Vehicles
Mach E Premium SR AWD
Occupation
Engineer
Country flag
Oy, this thread!

Ask an electrician. Not the internet.
You should see the Reddit threads. People running 100’ extension cords out apartment windows to charge their teslas. It’s amazing there aren’t more self inflicted fires with that kind of stupidity.
Sponsored

 

Maquis

Well-Known Member
First Name
Dave
Joined
Dec 21, 2020
Threads
34
Messages
5,688
Reaction score
8,068
Location
Illinois
Vehicles
2021 Mach E4X, 2023 Lightning Lariat ER
Country flag
Correct, 48amps, which is 11.52KW. My house varies on the V, seen as high as 248 or 249, so closer to 11.9KW.

I just ran it at 48amps, and it maxed out at 11.27Kw.


charging.PNG
Correct - I’ll update my post.
 

JmanMachE

Active Member
First Name
Jerry
Joined
Oct 16, 2021
Threads
0
Messages
35
Reaction score
22
Location
Needham, MA
Vehicles
2021 Mach E Premium AWD ext. range
Country flag
I installed the ChargePoint Flex hardwired which can deliver up to 48 amps (60 amp circuit). It works very well. The car will charge as quickly as it can with this, but a few things I learned afterwards.

At the higher rates (48 or 40 amps out), the MME will run more cooling and that can be very noisy. I was shocked the first time and researched it, but at least it keeps the batteries from overheating. I also believe I'm losing some additional power due to this. In hot weather, it was taking much longer to charge than expected at these higher rates.

For the most part, I keep the charger set at 40 amps (32 amps output) - same as the Ford charger. This seems to be the sweet spot - fast enough for me, still quiet and not wasting energy cooling the batteries. I can always increase it if I need the speed, simple to do from the app.

I wouldn't recommend anyone use 110 simply because the energy loss through the wiring is significant, and of course that is magnified over time since it will take days to reach full charge.

Hope this is helpful.
 

RickMachE

Well-Known Member
Joined
Jul 1, 2021
Threads
267
Messages
17,912
Reaction score
27,889
Location
SE MI
Vehicles
2022 Mach-E Premium 4X, 2022 Lightning Lariat ER
Country flag
I installed the ChargePoint Flex hardwired which can deliver up to 48 amps (60 amp circuit). It works very well. The car will charge as quickly as it can with this, but a few things I learned afterwards.

At the higher rates (48 or 40 amps out), the MME will run more cooling and that can be very noisy. I was shocked the first time and researched it, but at least it keeps the batteries from overheating. I also believe I'm losing some additional power due to this. In hot weather, it was taking much longer to charge than expected at these higher rates.

For the most part, I keep the charger set at 40 amps (32 amps output) - same as the Ford charger. This seems to be the sweet spot - fast enough for me, still quiet and not wasting energy cooling the batteries. I can always increase it if I need the speed, simple to do from the app.

I wouldn't recommend anyone use 110 simply because the energy loss through the wiring is significant, and of course that is magnified over time since it will take days to reach full charge.

Hope this is helpful.
The charging noise at 48amps was fixed by an update, I had it done last September(?). There is no noise now.
 

dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
126
Messages
4,822
Reaction score
4,525
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
Correct, 48amps, which is 11.52KW. My house varies on the V, seen as high as 248 or 249, so closer to 11.9KW.

I just ran it at 48amps, and it maxed out at 11.27Kw.


charging.PNG
thanks for the verification.... you and @delacruz.c5d clearly show the MME can take 48amps

I was going by the docs; which as we've seen are not always 'accurate'.

the standard 32amp mobile is fine for me at home, my average day is 20-50miles, and we don't have time-of-use rates in NM, so I don't have to hit any particular window when charging....
 


dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
126
Messages
4,822
Reaction score
4,525
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
...snip

For the most part, I keep the charger set at 40 amps (32 amps output) - same as the Ford charger. This seems to be the sweet spot - fast enough for me, still quiet and not wasting energy cooling the batteries. ...snip
so..... if the OP doesn't NEED faster charging, the mobile at 32amps is just dandy.


I wouldn't recommend anyone use 110 simply because the energy loss through the wiring is significant, and of course that is magnified over time since it will take days to reach full charge.

Hope this is helpful.
I object to your statement that 'loss through wiring is significant' charging from 120v. If the wiring between breaker and outlet is standard 12ga copper, and less than 25feet, the loss from wire is TINY. If you have a long extension cord that is 14ga or 16ga from outlet to mobile charger it might get pretty warm and be a problem.

Of you must use an extension cord, get a 10ga cord, and make sure it is as short as possible.
 

walla2

Well-Known Member
First Name
David
Joined
May 1, 2021
Threads
7
Messages
149
Reaction score
273
Location
Walla Walla, WA
Vehicles
21 MME Prem ER AWD, 2017 Toyota Highlander
Occupation
Clergy
Country flag
Difference between 32 or 40 amp L2 charger?

To my mind it's about 8 amps.

(Tip your waiters, try the veal, it's delicious...)
 
OP
OP

YFD_233

Well-Known Member
First Name
Scott
Joined
Jan 15, 2022
Threads
6
Messages
78
Reaction score
40
Location
NY
Vehicles
2021 Durango RT,
Occupation
Firefighter
Country flag
40 or 50 only for a nema 14-50 socket


correct about the 125%, but you are allowed to put a 14-50 on a 40A circuit


yes, with 6 ga copper you can use a 40A or 50A breaker.
6 ga for 40A?
Ford Mustang Mach-E Difference in installing a 32 or 40 amp level 2 charger? 26C59C39-0A4A-4AF7-BB1C-C3996EF75A31
 

timbop

Well-Known Member
First Name
Tim
Joined
Jan 3, 2020
Threads
65
Messages
6,832
Reaction score
14,036
Location
New Jersey
Vehicles
Solar powered 2021 MME ER RWD (CA RT1)
Occupation
Software Engineer
Country flag
6 ga for 40A?
26C59C39-0A4A-4AF7-BB1C-C3996EF75A31.webp
#8 copper is the MINIMUM for a 40 amp circuit - but you can use heavier wire than you need so #6 will work for either 40A or 50A. The only reason to use heavier wire is "just in case": you never know what the future will bring and as I mentioned before running heavier wire prevents you from having to "do it over". You can run #6 on a 40A breaker with a 32A or lower EVSE. Then, at some point in the future when you have 2 EV's in the house you can replace the single EVSE with a dual-port one that can charge 2 cars at a time.

If you'd rather save the $50 and use #8 for your 40A line it will work just fine. I used #8 off of a 40A breaker to my 32A EVSE because I had leftover #8 wire and the panel is only 15 feet from the EVSE. So for me if I can talk my wife into getting a BEV I will run a second 40A line for her car (we have 200A service with plenty of headroom). If my run was long and/or difficult or my panel was on the verge of being maxed out I would have run #6 on a 50A breaker with the plan to get a tandem EVSE in the future.

In place of a tandem EVSE you can get one that can circuit-share with another of the same model.
 

SMann40544

Member
First Name
Sloan
Joined
Feb 6, 2022
Threads
1
Messages
14
Reaction score
17
Location
High Point, NC
Vehicles
2021 Mustang Mach E GT
Occupation
MD
Country flag
Above is my MME GT charging off of a charge point hardwired to a 50 amp circuit breaker.
V=IR, Amp=Power/Volts

This is 9.674 KW and about 44 amps at 220 Volts.
 

EELinneman

Well-Known Member
First Name
Eric
Joined
May 4, 2021
Threads
96
Messages
1,482
Reaction score
2,423
Location
Littleton, CO
Vehicles
Mustang Mach-E GT Performance Edition
Occupation
Sr. Dir Cloud & Projects
Country flag
Ok guys. What’s the difference in installing a 32 or 40 amp level 2 charger? And what’s a good cheaper one to get, so many to choose from?
Keep in mind that the circuit has to be derated by 20%, so a 32 amp EVSE needs a 40 am circuit breaker, a 40 amp EVSE needs a 50 amp breaker. Make sure your electrician wires this correctly.

As far as chargers go, the go to review is Tom Mologny (sp?) on You Tube. His channel is titled "State of Charge". I got a Juicebox via Costco and am very happy with it.
Sponsored

 
 







Top