[Honolulu]

Per the title, 2019 530e with 30,000 miles, have had the car for 1.5 years.

Occasionally on the morning after I or my wife come home with a fully depleted battery and plugged into a 20A circuit, there is very little charge in the battery. Apparently the car stops charging several minutes after being connected.

Local ambient temps usually in the upper 70s F though surely the battery is good and warm.

Why would this failure to charge occur? One 20A circuit is all I have b/c my panel breaker slots are already fully occupied, and that circuit also powers the kitchen microwave. Although simultaneously using the micro and charging the car sometimes shuts off the breaker, frequently after charging overnight the battery is (very) incompletely charged, the breaker isn't/hasn't tripped, ergo no house circuit overload occurred the previous night.

I wonder/wander in several directions:

1. I don't know of any high grid loads in my area, but I wonder if the grid is stable in my 90-year old neighborhood.
2. I had the charge cable replaced shortly after I got the car. Possibly another fault in the cable? I'm out of warranty and not liking the idea of full dealer rates as I've previously done almost all my own work (have had 30 Bimmers).

Any suggestions welcome, TIA.
Charlie in Honolulul, Hawaii

[LogicalApex]

What does the car and EVSE show when this shutoff occurs?

The car may be shutting off due to no ground wire detected and other handshaking between the EVSE signaling it to stop.

Also, what is your charge limit set to in the car? You should set it lower on a shared breaker. Since this is shared with other appliances I assume it is 120V Level 1 and not 240V Level 2. The car allows setting a charge current limit for Level 1 only. This can be set via iDrive or the MyBMW App.

Charging when the batteries are warm isn't a concern as the car will cool the batteries as needed to keep them in a safe range when charging...

[d4700]

If you're able to read them, the car should log some more descriptive fault codes that will point you in the right direction. Could be a charging control module issue, EVSE issue, or (unlikely) unstable grid power.

I'd imagine the reason it tends to quit when you have an empty battery is that the charging current is highest in this scenario. I'm not sure whether you use 120 or 240v, but when monitoring my 240v charge cycle during the battery test plan in ISTA, the current started around 11A and tapered down to something around 1-2A as the battery reached capacity.

[Honolulu]

Thanks for the feedback.

I have only a generic code reader, so there's no deep dive information I can retrieve.

I recharge from a 120V 20A circuit. The car is set to the lowest charge rate, to respect the capacity of that circuit breaker. When plugging in the charge cord, the car at first accepts current, then fails after some relatively short time, judging by the absence or significant battery recharge.

I was quoted an uncomfortable amount to install a new 220V outlet, in part b/c my existing breaker panel has no open slots, further (possibly) complicated by presence of solar power generation presence. My 2-story house has a separate breaker panel serving the vacant downstairs residential unit. Maybe a new 220V circuit can be run from that panel, will have to inquire with a qualified electrical contractor.

[LogicalApex]

Originally Posted by Honolulu

Thanks for the feedback.

I have only a generic code reader, so there's no deep dive information I can retrieve.

I recharge from a 120V 20A circuit. The car is set to the lowest charge rate, to respect the capacity of that circuit breaker. When plugging in the charge cord, the car at first accepts current, then fails after some relatively short time, judging by the absence or significant battery recharge.

I was quoted an uncomfortable amount to install a new 220V outlet, in part b/c my existing breaker panel has no open slots, further (possibly) complicated by presence of solar power generation presence. My 2-story house has a separate breaker panel serving the vacant downstairs residential unit. Maybe a new 220V circuit can be run from that panel, will have to inquire with a qualified electrical contractor.

Also check the grounding on the outlet and breaker. The charger is in the car and the car will stop charging if it can’t detect a ground or if the ground is unstable (corroded, etc).