Home Level 2 charging slower than expected

[Mustang65]

I have a Grizzl-E classic charger that is rated and set up to provide 40 amps (9600 watts) but my Mach E (2022 GTPE) and home power monitor both report it to be 33 amps (8000 watts). I've seen discussions here about the car rate limiting Level 3 fast DC charging, but does it also rate limit Level 2 as well? My charging is done at night, several hours after last driving it and multiple sessions have shown the same 8kW charge rate. I'm typically starting charging at about the same point, 15 to 20% range remaining.

Any guesses why I'm not seeing more like the max rate?

I haven't tried the Ford charger that came with the car, but I'm wondering if it will behave differently.

Sponsored

 

[kennethjk]

Read this thread

https://www.macheforum.com/site/threads/l2-charging-speed-recently-dropped-33.28779/

 

[AliRafiee]

8kw is typical.

 

[E-PonyExpress]

I average closer to 10….

 

[RickMachE]

I have a Grizzl-E classic charger that is rated and set up to provide 40 amps (9600 watts) but my Mach E (2022 GTPE) and home power monitor both report it to be 33 amps (8000 watts). I've seen discussions here about the car rate limiting Level 3 fast DC charging, but does it also rate limit Level 2 as well? My charging is done at night, several hours after last driving it and multiple sessions have shown the same 8kW charge rate. I'm typically starting charging at about the same point, 15 to 20% range remaining.

Any guesses why I'm not seeing more like the max rate?

I haven't tried the Ford charger that came with the car, but I'm wondering if it will behave differently.

Mach-E doesn't tell you charging speed, FordPass does. And it truncates the decimal point digit.

40 x 240 = 9.6 less 10% loss = 8.6. So FordPass should show 8, as it does.

Your home power monitor should be showing power actually used, so it should be closer to 9.6. Does Grizzl-E have an app?

I average closer to 10….

Not with a 40amp charger you don't. 40 x 240 = 9.6 less 10% loss = 8.6. 48amp charger would be a net of 10.4 or so, or worse.

 

[mkhuffman]

The Grizzl-e has an internal switch where you can control the max current output. If it is really pulling 33 instead of 40 Amps, you could check that to see if the switch is in the wrong place.

 

[E-PonyExpress]

Mach-E doesn't tell you charging speed, FordPass does. And it truncates the decimal point digit.

40 x 240 = 9.6 less 10% loss = 8.6. So FordPass should show 8, as it does.

Your home power monitor should be showing power actually used, so it should be closer to 9.6. Does Grizzl-E have an app?




Not with a 40amp charger you don't. 40 x 240 = 9.6 less 10% loss = 8.6. 48amp charger would be a net of 10.4 or so, or worse.

You are correct.

 

[IMDIDOC]

I have an external digital meter ahead of the Grizzl-e. Sometimes it's 9kw and sometimes it's 7. I've noticed that if I just get home and plug it in, it may not get to 9kw. The front louvers open and the fan runs. Most likely too hot to take the max current. Also, if the battery is near full, it may not charge at max rate.

 

[bdonpwn]

And for anyone that isn’t too familiar with this, to concisely clarify, inline/device metering happens before losses at the EVSE whereas FordPass and energy delivered is after losses.

 

[DadzBoyz]

What size fuse is your EVSE operating on?
If your Grizzle-E is capable of 40 amps, and you’re on a 40amp fuse, it may be automatically downrating itself to 32 amps.

Normally, you want to use a fuse rated such that your EVSE uses 80% of its capacity. It’s not exact, as fuses usually come in 5 amp increments, in which case you go high.

48-50 amp EVSE —-> 60 amp fuse (The Mach-E tops at 48 amps for Type 2 EVSE’s, so your good at 60 amps.)

40 amp EVSE —-> 50 amp fuse

32 amp EVSE —-> 40 amp fuse (This is sounds suspiciously close to what you’re describing.)

OR, your fuse box could be out of power, in which case you could add a separate box with more service.

 

[Coffs]

I have a Grizzl-E classic charger that is rated and set up to provide 40 amps (9600 watts) but my Mach E (2022 GTPE) and home power monitor both report it to be 33 amps (8000 watts). I've seen discussions here about the car rate limiting Level 3 fast DC charging, but does it also rate limit Level 2 as well? My charging is done at night, several hours after last driving it and multiple sessions have shown the same 8kW charge rate. I'm typically starting charging at about the same point, 15 to 20% range remaining.

Any guesses why I'm not seeing more like the max rate?

I haven't tried the Ford charger that came with the car, but I'm wondering if it will behave differently.

I've got the exact same, charger should be 40A (9.6kW) but Ford app reports 8kW. When I look at range gained per hour it's getting 28-30 which does correspond with 9.6kW so it's ok, Ford is lying to you.

 

[nuMach]

"What size fuse is your EVSE operating on?
If your Grizzle-E is capable of 40 amps, and you’re on a 40amp fuse, it may be automatically downrating itself to 32 amps."

++++ the charger doesnt 'talk' to the fuse/breaker


"OR, your fuse box could be out of power, in which case you could add a separate box with more service."

++++ the panel doesn't limit the power, other than tripping the main breaker if the house load exceeds its rated ampacity ... nor do individual circuits.

+++ circuits should have wire size and breaker sized for 125% of the continuous demand of load.
Its a safety thing due to the load being steady over a long period.


so, if you want 40 A - you need a 50A breaker. #6 wire
if you want 48A ... you need a 60A breaker, #6 wire - They dont sell 55's

If your panel has fuses .... its probably so old you should have it checked over by an electrician before adding a charger.

 

[nuMach]

dont have a grizz, however the app for my L2 charger lets me set the rate.
Initially it defaulted to 28A, and I had to pick 40 in the config settings.

So dunno if its something that simple.

I find my L2 charger delivers the 40A rate until about 20min before it hits 90%. From 30% its about 4+ hours.
I suspect the car is tapering it off, or the battery is 'pushing back' because its near full, and doesnt draw as much.

 

[dbsb3233]

If your Grizzle-E is capable of 40 amps, and you’re on a 40amp fuse, it may be automatically downrating itself to 32 amps.

I don't think breakers/fuses have the ability to "downrate" the power level. They simply trip (breaker) or blow (fuse) if they detect more amperage drawn on the circuit than they're rated for. All-or-nothing.

 

[dbsb3233]

I have an external digital meter ahead of the Grizzl-e. Sometimes it's 9kw and sometimes it's 7. I've noticed that if I just get home and plug it in, it may not get to 9kw. The front louvers open and the fan runs. Most likely too hot to take the max current. Also, if the battery is near full, it may not charge at max rate.

Home voltage can vary too, especially during higher load times. You and your neighbors could be using more A/C, oven, etc earlier in the evening than later.

Sponsored