What is your EVSE? I have JuiceBox 40 and see pretty much the same charge rate and voltage values, but mine is 40 A max by design. Perhaps, your has an option to limit the current to 40 A? Some of them have jumpers and some of them (smart ones) have a software setting.

 

Wallbox 48A and it was doing 11.5kW when installed.

 

Carefully feel all of the connections, to see if they're hot, including the breakers. Anything above barely warm indicates that you have a connection problem there. Heat equals energy loss.

 

Will look at that thanks.

 

Wallbox's web site mentions "Adjustable current: from 16A to 48A". If this is a software setting, it could have easily changed after some update... "If software does not have bugs, it means you just didn't find one yet"

 

I am aware of the settings for 48A - the current setting (pun intended) is present on the control interface.

Note in my original post that the vendor was seeing input voltage fluctuations.

 

Sorry, but I have to ask. Is your EVSE on a 60A circuit? You mention Qmerit as the installer, but the GM/Qmerit installation is usually only for a 40A circuit and Nema 14-50 plug.

 

Yes on a 60A circuit. It was Qmerit but over and above the covered install.

 

@MiG When was the install done and how long have you been having this issue?

 

Done in July, but can't say how long I have been having it. The car charges overnight in plenty of time so haven't really paid attention.

Just noticed about two weeks ago when I checked the app and saw something like 9.6kW. Then was reading in a thread about ramping down in L2 charging -- which I didn't think was a thing (just DCFC). So then started paying more attention.

 

Is it possible that maybe the Bolt EV arrives close to full and there is a throttle of the charge ? When Qmerit did the work, did you check if your car receives 11.5 kW before giving them the OK ?

How many kWh your car uses every day ? If your car starts the charge @ 9 p.m., in 6 hours (till 3 a.m. when you see the drop) it added already 11.5 x 6 kWh. That’s more than a full battery, if my understanding is correct. Before anything, I’d set the Delay charge for 7 a.m. and check in the morning how it all went, is the 3 a.m. drop still present ?

 

Yes it was doing 11.5kW before. I have been running the car down below 50% SOC, next test will be even lower. My understanding is that I should be seeing 11.5kW at the beginning (or at least in the first hour since I am in the frozen tundra).

 

If the Wallbox is seeing a voltage fluctuation, that sounds like an issue from your electrical service or even Utility. Do you have something that can monitor and log the voltage (besides the Wallbox unit) to share with the electrician and/or the utility?

 

That is what I am thinking. Want to do some more tests, particularly at lower SOC.

To me it is either a utility issue, (one leg is down) or maybe the tap off the other meter.
(they tap off the input to the other meter)

Checking on logging voltmeter costs.

 

Have you measured amp draw while charging, or just kW? Seems like the voltage drop alone is almost enough to explain the difference in charging speed. Of course, that would also require that the voltage drop is a new phenomenon that wasn’t present when you were seeing 11.5 kW soon after install.

 

I don't mean to sound like a broken record, but you did check to see that the dip switch is set to 7 and not 6, right? I know it should be 7 by default, but that doesn't mean it didn't accidentally get changed at some point.

 

You are not a broken record. The current selector is set to 7. (I think it should go to 11)

 

I would think any installation problem (resistance) that causes that much of a voltage dip would have already caused a severe event.

One thing that could cause voltage fluctuations is an on-line tap changing (voltage adjusting) transformer. But that would affect (and may be affecting) your whole neighborhood. I would contact the utility and say you suspect system voltage fluctuations. You already have the data to show that.

Then let them research and maybe do their own data logging.

 

Good idea, thanks.

 

Yeah, it looks like you voltage is just really low for some reason. I'll be interested to see what readings you get. With the right app, you could pull this from the OBD2 port... but a multimeter can obviously do the same thing.

I'm surprised the WallBox app doesn't give you line voltage... most the of the apps do.

 

It seems like the OP’s EVSE can measure and log line voltage.

 

I'm going to go with what pretty much everyone said and say: the voltage sag is causing power loss. If your house hasn't burnt down yet then it might be the utility. It is entirely possible that the grid itself sags late at night. Personally, I have a ChargePoint Flex on a 60A circuit and it really does about 11kw all of the time. At the very end of charge it very rapidly tapers off but until then it is pegged at 11kw according to the chargepoint app. It isn't really normal for things to be stuck at 9.6kw if you told it to do 48A. But, the reason power companies want you to charge late at night is because the grid has excess capacity at those hours (usually). They have to throttle the power plants back at night. Maybe your local utility is overdoing that a bit and the voltage sags. Power companies are very careful to average 60Hz on the grid over the long haul (hours, days) but they are not quite as careful about matching the target voltage. Still, the drop you are seeing is way too much. If they're sagging then they need to knock it off. Power companies have a whole lot of monitoring equipment and if enough people near you complain they can find it and fix it. But, if it's your house you are very likely to eventually start a fire. That phantom 1 - 1.5kw of power loss would be going somewhere if its a fault in your wiring. You do not want a surprise 1.5kw heater in some random spot in your house. The two best ways to figure this out are 1: feel around for hot spots as others have said or 2: measure voltage at the EVSE and as far toward the meter as possible. The voltage at both points should be almost the same. You could even ask the car as its charger knows the incoming voltage. If there is a large voltage drop in your equipment (that is, you measure 240V at the meter box but the EVSE or car say 206v) then cease using the EVSE until you figure it out.

 

If there is a large voltage drop in your equipment (that is, you measure 240V at the meter box but the EVSE or car say 206v) then cease using the EVSE until you figure it out.

Or just turn the current selector down. One of the EVSEs I used to use had a voltage monitoring function where it would automatically lower the amperage if the line voltage started to drop. I tried to get it to do this… I charged the Bolt from about 10% to 100% on a 30 amp circuit with the EVSE pulling 32 amps. I monitored the temperature of the breaker, wiring, and outlet. I had a 50 foot 30 amp RV extension cord to the EVSE. Unfortunately, I wasn’t able to get it to drop voltage enough to trigger an amperage drop… and nothing in the system overheated or tripped. You can’t even burn things down when you try, sometimes!

 

So 10pm rolls around just now, and EVSE app showing 9.6kW.

Measured voltage at EVSE and it shows 120, 120 and 240. Input seems right.

Will let it go for an hour and check power on app and see if there is a change. Will also check to see if anything is getting hot.

(not expecting remote troubleshooting here on forum, just updating what I am doing. But thanks again for all the suggestions)

 

1 hour 29 minutes into charging now at 10.1kW. Will give it another half hour.

 

That's weird. If the voltage is nominal, but the power is low, that means the amperage is low. If nothing is overheating, then I would suspect a faulty EVSE or a faulty onboard charger in the Bolt. Is there anywhere you can try a different 48A Level 2 charger (to rule out the Bolt)?

 

It is weird. Not sure in my area, but will check around.

Bolt in garage 43ºF (been going for 2:06 and now at 10.3kW)

'night

 

If line voltage is steady it could simply be the Bolt's charger is limiting amperage due to a cold battery. The charging is warming the battery so the current is slowly ramping up.

 

The Bolt shouldn't have any taper or limitation for Level 2 charging. Those should only apply to DCFC.

 

I know your EVSE says 48 amps, but is that simply the setting and not the draw? I have an Emporia EVSE that can display either watts or amps in the app. I have it set at 24 amps, but it normally shows 23 actual while charging. Can you monitor the actual amps?

 

Yes that is the setting. The only thing I can see on my app is the kW.

 

Here is something to try:
Set the charger to 40A ..
If your voltage is actually dropping at night, it Should also effect the 40A ( & all the lower) settings as well, & you wont be getting 9.6kW or whatever is rated for the lower settings with that either ....
If the charger is fine on any of the 40A or lower settings, then perhaps either the charger as it gets "warm" @ 48A is causing the drop/problem, or wiring/connections/breaker to the charger are doing it, assuming the entire house isn't dropping voltage @ 3AM, only the charger circuit....
I would think if 240 is lowering to 213V at night, then 120V is around 106-107v at night, if the problem is on all circuits .. ...

 

Does a neighbor on the same utility transformer as you also have an EV?

If so, do they have it on a timer to start charging at 3AM?

 

Nice try but no. Same transformer but no EV.

I think the cold weather could be the thing... I am traveling (w/o Bolt) next week when it gets warm, so will try a test then. Also looking for L2 11.5kW public charger tomorrow to test.

I assume I can read the kW rate on the charger (or I thought someone mentioned you can turn on the car and see the energy the DIC where you normally see the use/regen level)

 

I have been troubleshooting an issue with home charging with 48A EVSE. I noticed it was charging at something like 9kW (posted in another thread) rather than 11.5kW.

Checking with EVSE manufacturer and they had me do some voltage measurements (not during charging) which all line up. (Actually they asked me to have an electrician do the measurements, but I feel okay doing what they needed.)

About 123 on both legs and 247 across the legs.

But during a charging session they notice on there backend that around 3am they saw fluctuations between 239 and 213.
View attachment 54697
View attachment 54698


They recommend contacting the electrician that did the install (via Qmerit) to check things out. Which I will do.
Has anyone had any experience with Qmerti warranty? Reading the paperwork it seems like it is just warrantied through the electrical contractor.

I think it will be difficult to get an electrician to see the problem occurring - not sure many make 3am calls. But I would guess if there is a problem after the meter it should be obvious.

As far as the problem - it is a separate meter off my regular incoming service but not controlled by utility.
It is just a separate meter that is read for the lower rate.

This is beyond me. If you can connect the OEM charger at 110v and select 8 or 12 amps x hr. Is reasonable put good money in a 220v installation for a charger? Is necessary? If you drive a lot, yes. I drive 65 miles, more or less each day. And I change at 8 amps, if is not full today I don’t care. I have over 200 miles range anyway. Anyway the fact is I never filled the gasoline tank each day wen I have a regular car, and I don’t need have 100% each night… well in fact I limit to 89%. I never change to 100% (Well some times, in 4 years 3 times. Wen they delivery the car at the dealership, one time wen they replace the battery and one time I drive a long distance, and was no necessary. I have to change my plans because some charging stations are out of order and I need stop every 150 miles and I plug for 1 hr each time, and never get to 100% in 1 hr

 

All very valid points. I think using the OEM charger is a great idea. As has been said many times on this site, you don't need anything other than the OEM EVSE if you know your needs.

For me I wanted to have the OEM charger in the trunk for travels, so I needed an EVSE and had the Qmerit option. I certainly could have just used the OEM EVSE for all my charging and thrown (placed) it in the trunk when I need it.

Also, I'm in a cold weather location so I need to charge more frequently -- particularly when I can take advantage of off-peak rates of .05kWh. (Only this past week I am starting to see 200 mile range on the GOM with a full charge.)

I also charge to 95-100% so I have the flexibility to drive longer trips when I need to. Two weeks ago I wanted to go about 90 miles one way. I could because the car was charged and ready to go. If it wasn't then I would need to "plan" more, search out DCFCs etc. But I didn't have to.

For me charging to 80% because I don't want to "degrade" the battery means that the battery is already degraded, because I am only getting 80% out of it. I bought the car to drive, not to sell it later. But that is me.

If I had more control of when I need to drive, I would do things differently.

(Regarding the gas analogy of never filling each day, the time to refill a gas tank is quite different than charging.)

 

My EUV won't charge at 11.5kw either, but my Tesla does immediately with the same charger. I figured it was something in the cars software but haven't really looked in to it since it charges in plenty of time overnight.

 

I and my buddy with a 2023 Bolt EUV are in the same situation. I have taken it to the dealer and they have confirmed that they cannot get mine to charge beyond 10.2kw. BUT... since there are no trouble codes, the dealer says the vehicle is working fine. Despite the 11.5kw max charging spec.

I'm taking a break from tilting at that windmill. My complaint is on my vehicle's record and I will bring it up every time I take it in. Someday maybe it will get acknowledged as a real issue.