L2 Charging Very Slow

hello,
i took possession of a new BEV 2017 yesterday . loved the ride home from the dealership.
anyway. i have installed the Levinton 40A/240V charging station.
the car low cost charging is set from 11:00p-9:00a, depurture time set to 8:35a. tech guy that set it up for me at the dealership, said that if the departure is set before end of low cost charging the precondition will never kick in.
when i left the car last night (ca. 9:00p) the battery was at 75%. this morning 9 hr later is at 86% and still charging. i expected 100% of course.
the display shows charging at 3 miKwh.
definitely something wrong. any advice what to check, how to change settings?
appreciate your help

We need to see if you have the 7.2 kW charger option. Use the last seven characters of your VIN to check the equipment list. Google "BMW VIN checker."

Mine is: V277136 and supports 7.2 kW charge rates. Compare it to yours. I also have the fast DC charger option.

GOOD LUCK!
Bob Wilson

onufry said:

how to change settings?

Click to expand...

Did the guy at the dealership point out that L2 charging is set, by default, to "Reduced" - 20A, instead of "Maximum" - 32A? You can set this via iDrive. Go to Settings/Charging/Level 2. Set it to Maximum.

I think BMW did that because some L2 chargers are 30A and some are 40A. If your L2 charger is on a 40A circuit, you can set the L2 charging to "Maximum".

Where did you see the charging rate? My car doesn't show it, only the estimated full charge time.
Not sure about you 2017, my 2015 charges full blast until the battery reaches 85-88%, after that the current is reduced. What you describe is not right. You should try another L2 charger. Just stop by any public charger. Even if the charger has no display, you should see 1 mile of range added every 2-3 minutes. If the problem persists, the car might have a problem.

Curious as well about the charging rate display... Or did you get it off the L2 charger?

I'm in the process of having a ChargePoint L2 home charger installed. Going through the manual, it does mention that the companion app can report the charging rate in rangeDistance/time.

i will check tomorrow morning again. i saw 3mi/kwh or at least i thought i did see something like that on the display. i might be an ignorant novice that does needs reading glasses.

both L1 and L2 are set to MAX.

cdnji said:

onufry said:

how to change settings?

Click to expand...

Did the guy at the dealership point out that L2 charging is set, by default, to "Reduced" - 20A, instead of "Maximum" - 32A? You can set this via iDrive. Go to Settings/Charging/Level 2. Set it to Maximum.

I think BMW did that because some L2 chargers are 30A and some are 40A. If your L2 charger is on a 40A circuit, you can set the L2 charging to "Maximum".

Click to expand...

i see these:
S4U7 Rapid charging, direct current
S4U8 Rapid charging, alternating current

bwilson4web said:

We need to see if you have the 7.2 kW charger option. Use the last seven characters of your VIN to check the equipment list. Google "BMW VIN checker."

Mine is: V277136 and supports 7.2 kW charge rates. Compare it to yours. I also have the fast DC charger option.

GOOD LUCK!
Bob Wilson

Click to expand...

Nowhere on the car or in the iRemote app does it show the actual instantaneous charging rate. In the iDrive menu, under charging, you should have an entry to adjust the L1 and L2 (well, in Europe, you might not have an L1 adjustment) that the only reason to set it to other than maximum is if the EVSE is on a shared circuit and drawing what the EVSE says would overload its power branch. It hurts nothing if the car is set to maximum (32A peak) and the EVSE can't provide that since the car won't draw more than the EVSE says it has.

The time readout in the car shows when the car thinks it will finish charging. FWIW, I've found that if you have preconditioning and departure times set on a cold day, it can draw as much as 20-21A, so if your car is set to only allow 20A maximum, you'll be going backwards in the charge. You really need the car set to maximum and an EVSE that can provide more like 25-30A to have a net inflow of power during the actual time it's warming things up.

onufry said:

i see these:
S4U7 Rapid charging, direct current
S4U8 Rapid charging, alternating current
. . .

Click to expand...

Good that leaves several hypothesis:

• 1) Malfunction - new car, unlikely, but should be checked at dealer.
  2) Configuration of charger (EVSE.)
  3) Inverted power saving mode.
  4) Preconditioning effects.

So this is what my 60Ahr, BMW i3-REx sees:

• L1 12A @120 VAC, ~1.3 kW - ~4% per hour without preconditioning.
  L2 30A @240 VAC, ~7.2 kW - ~20% per hour without preconditioning.

So let's work the problem in reverse:

onufry said:

. . . the battery was at 75%. this morning 9 hr later is at 86% . . .

Click to expand...

So that gives 10% / 9 hrs ~= 1.1% per hour. Not good!

Let's assume a 96 Ahr battery versus my 60 Ahr, 1.1% * (96/60) ~= 1.8% per hour, still too slow.

I would start by reducing everything to the minimum; (1) turn off vehicle preconditioning menu, (2) verify L1 is set to max, and (3) use the portable EVSE to charge the car over 3-4 hours. Then calculate the change of SOC per hour.

What is your local house voltage for the portable EVSE? The reason I ask is the portable appears to be set to 12A maximum. If you have a higher voltage, the charge rate should be higher.

What are the local temperatures? The reason I ask is the car protects the battery so if temperatures are freezing or below, the car may be using charge power to keep the battery in operating temperature range.

Bob Wilson

hey,

this morning observations:
@8:00p last night - 56%
@6:00a this morning - 70%
@7:00a this morning - 92%
@8:15a this morning - 100% - that's when i checked - possibly reached the 100% earlier.

this got me thinking that my setup is incorrect.
tech (bmw) set the low cost to start at 11:00p and end at 9:00. with preconditioning on and departure time at 8:35a.
is it possible that the precondition and departure settings delay actual charging to kick in?

temps outside were quite low last night. definitely below 0C. at 6:00a was -8C. not sure what was the temp inside the garage.
local voltage is standard 110V/120v.

cheers

bwilson4web said:

onufry said:

i see these:
S4U7 Rapid charging, direct current
S4U8 Rapid charging, alternating current
. . .

Click to expand...

Good that leaves several hypothesis:

• 1) Malfunction - new car, unlikely, but should be checked at dealer.
  2) Configuration of charger (EVSE.)
  3) Inverted power saving mode.
  4) Preconditioning effects.

So this is what my 60Ahr, BMW i3-REx sees:

• L1 12A @120 VAC, ~1.3 kW - ~4% per hour without preconditioning.
  L2 30A @240 VAC, ~7.2 kW - ~20% per hour without preconditioning.

So let's work the problem in reverse:

onufry said:

. . . the battery was at 75%. this morning 9 hr later is at 86% . . .

Click to expand...

So that gives 10% / 9 hrs ~= 1.1% per hour. Not good!

Let's assume a 96 Ahr battery versus my 60 Ahr, 1.1% * (96/60) ~= 1.8% per hour, still too slow.

I would start by reducing everything to the minimum; (1) turn off vehicle preconditioning menu, (2) verify L1 is set to max, and (3) use the portable EVSE to charge the car over 3-4 hours. Then calculate the change of SOC per hour.

What is your local house voltage for the portable EVSE? The reason I ask is the portable appears to be set to 12A maximum. If you have a higher voltage, the charge rate should be higher.

What are the local temperatures? The reason I ask is the car protects the battery so if temperatures are freezing or below, the car may be using charge power to keep the battery in operating temperature range.

Bob Wilson

Click to expand...

I don't have easy access to low-cost charging, so take this as hearsay...unless the SOC is quite low, when you have a departure time and low-cost charging, since the act of charging the batteries heats them somewhat, the car will wait to start charging. This saves some energy when it's cold out since charging at the beginning of your window might allow things to cool off significantly before it then had to start to heat them back up again. This is a good practice UNLESS you find yourself needing to leave earlier for some reason...then, it will neither be fully charged nor as warm as it could have been. If the SOC is quite low, it will bring the battery charge up some, then pause until the low-cost time window to help prevent possible damage to the battery pack from the cold.

hi
thanks for the info.
i guess that makes sense. we do have cold temps now in Toronto. Currently -11C @ 5:15am.
i went this morning around 5:00am to check the status and i had 70% charged (i-remote). i went to the car to confirm, and while sitting in the car the charging started. maybe i should change the end time of lowcost charging to say 6:00am, and see the difference.

cheers

jadnashuanh said:

I don't have easy access to low-cost charging, so take this as hearsay...unless the SOC is quite low, when you have a departure time and low-cost charging, since the act of charging the batteries heats them somewhat, the car will wait to start charging. This saves some energy when it's cold out since charging at the beginning of your window might allow things to cool off significantly before it then had to start to heat them back up again. This is a good practice UNLESS you find yourself needing to leave earlier for some reason...then, it will neither be fully charged nor as warm as it could have been. If the SOC is quite low, it will bring the battery charge up some, then pause until the low-cost time window to help prevent possible damage to the battery pack from the cold.

Click to expand...

Just for your reference. I am in London Ontario with similar weather last few days. I have level 1 charger only. I was able to charge from 60 to 100 over about 15 hours. This is similar to November, about 3% per hour.

I had a ChargePoint Home EVSE - 40A - installed today. With ChargePoint EVSEs, it is recommended that you sign-up and download their app - which I did.

1st thing I noticed was during setup, the app asked me the amp rating of the circuit breaker. In the setup message, the app states that if I do not explicitly confirm that the EVSE is connected to a 40A breaker, the EVSE will assume that it is connected to a 20A breaker and will behave as a Level 2 20A EVSE.

IIRC, I read somewhere that the i3 will only draw a maximum of 80% of the EVSE's amp rating. So for 20A, it's 16A max. For 40A, it's 32A max.

@onufry, maybe your Levinton needs a similar initialization.

I only used up 26% SOC today. iRemote reports that my i3 will be fully charged in a little over an hour.

cdnji said:

IIRC, I read somewhere that the i3 will only draw a maximum of 80% of the EVSE's amp rating. So for 20A, it's 16A max. For 40A, it's 32A max.

Click to expand...

An i3 and probably any EV will consume 100% of the EVSE's maximum current output. 80% is the maximum percentage of the charging circuit's rating that an EVSE should be configured to consume for safety reasons; e.g., for a 40A circuit, an EVSE should consume a maximum of 0.8 x 40A = 32A. I assume that a ChargePoint EVSE will configure itself to vend 80% of its circuit's rating based on user input whereas some other EV's require the installer or user to know not to exceed 80% of the charging circuit's rating when configuring the EVSE's maximum current.

A 40A EVSE would require a 50A circuit breaker in the USA to meet code because of the 80% rule.

The EVSE sends out a signal that identifies how much current it can provide, and it is up the car to then decide how much it will accept, but it can never try to pull more than the EVSE announces it has. Some EVSE's can be configured to announce less than their design values. On most, that's done with a DIP switch setting or a dial, but on an internet connected one, it could be done via software. The EVSE should not car one bit how much the car can use...the car will decide how much to take based on what's available. The goal is to not overload either the EVSE or its supply wiring. ANy EVSE worth its salt should not report it can provide more than it really can, but the thing does NOT know if it is wired properly from the supply.

Sorry for confusing everyone... I mixed up the breaker rating and the actual power level of the EVSE.

What I have is a ChargePoint 25 EVSE hardwired to a 40A circuit. The EVSE is rated to deliver 32A. For ref, here's the model buying guide page - http://www.chargepoint.com/home/buying/

Setting it up involved answering multiple choice question in the companion app to specify the circuit the EVSE is connected to. The choices were 20A or 40A circuit.

Is it possible that one half of your breaker is popped or faulty and you are only getting one phase delivered to your EVSE? I had that happen to a stove many years ago. I didn't look at your instructions to see if the EVSE reports input voltage/faults.