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On Board Charger issues

On Board Charger issues

Charging @Home with a 3.7 KW wallcharger (22Km/hour) and this is for my usage more then sufficient. Since some days, when connecting the charging session doesn't start and charging KM (on app and Screen) pending between 0 and 4 km.
Also the onboard charger is making more noise then normal. When charging without the wallcharger (17km/hour) charging starts immediate.
Is the onboard charger subject to defects? Does anyone know. I hate to go back to tesla store again, as this takes ages to get an appointment etc.Thanks

gmr6415 | 2020年1月22日

Probably pretty obvious, but have you set it up for a scheduled charge and your plugging in outside of that schedule?

Bighorn | 2020年1月22日

Has it been cold? Cold batteries don’t charge until they’ve been warmed by the car first.

derotam | 2020年1月22日

@Haan, So lets get some technical terminology out of the way. When using a wall outlet(AC power), the "Charger" is in the car. The cable you use to plug into the wall is called a Corded Mobile Connector, key word connector. If you have the wall mounted and hardwired option from Tesla, that is called a Wall Connector, again connector.

Now, charging rates due to temperature. If your battery is cold, then the car is going to use energy to heat the battery up first before being able to charge it because you cannot charge a Li-Ion battery below a certain temperature.

You ONLY have 3.7kW available and if the car wants to warm the battery it is going to put ~3.5kW to the rear motor(while not in motion) in order to get heat to heat the battery. This doesn't leave much charging ability.

Tesla's trigger points for heating are overly wide in my opinion and especially with home charging, battery heating is being used way too loosely by tesla.

The noise you are hearing is from the rear motor and the coolant pumps as power is being directed to the motor to generate heat to go to the battery.

Bighorn | 2020年1月22日

English is not his native tongue.

gmr6415 | 2020年1月22日

@Bighorn
"Has it been cold? Cold batteries don’t charge until they’ve been warmed by the car first."

It's interesting how we default to our own circumstances. Living in Central FL I don't think about cold while charging plus I use a 14-50 hookup, so I don't worry about the "warming" consuming almost as much as the circuit. This morning it was down to 31˚F which is pretty rare around here.

My wife and I were in the car, I had pre-warmed it to 68˚ (haven't done that in a long time) and turned her seat heater on about 15 minutes before leaving. The whole time taking her to work she was complaining about the heat not being effective enough, her feet were cold, etc. I pointed the heat toward the floorboard, but the complaints didn't stop.

After dropping her off I realized recirculate wasn't on, so the whole time I was pulling in cold air....palm to forehead...just don't think about that, that much around here. I looked at the energy chart, and I was consuming 390Wh/mi. I can't say I've ever seen that before under normal driving circumstances. At a stop, while on hold, I was also seeing the line indicating acceleration kind of blinking on and off to the load side. I assume that was current going to the stator and/or indicating I was consuming battery heating the car and the passenger seat. After setting it to recirculate it warmed up well and consumption dropped to 275Wh/mi.

I'm sure this is very obvious for people who use heat for months at a time.

Bighorn | 2020年1月22日

On the 2013 Model S, I can quantify how many kWs are going to climate and battery heating because there’s a big power meter where the speedometer belongs. When the battery gets into the mid 20s, there is no charging at all. It can take an hour for charging to start after plugging in, even at a supercharger. And efficiency numbers can skyrocket to 600 or even 900 Wh/m when it’s twenty below. That’s when a heated garage and plugged in car saves you.

jordanrichard | 2020年1月22日

Also what should be kept in mind, what we consider "cold" and what the battery considers "cold" are two different things. When it starts getting down into the mid 60's, energy usage, at least in my MS, starts to go up. If the car, more specifically the battery has been sitting outside without being plugged in, the battery will feel the affects of the lower temperatures. This subject has sooo many variables/scenarios, that there is no "one size fits all" answer. It's like comparing insurance rates. The BMS will do what it has to for the given situation/battery temperature/condition.

Haan | 2020年1月22日

Hi All, thanks and indeed not native English and technical terminology is more an issue then.(-:
And yes, it's a little colder here in Netherlands (around 0 degrees C)
I think that heating up the battery first is the issue and will monitor this. Indeed when having max 3.7 kW and it uses 3.5kW for heating up, then there is almost nothing left. I can see that the inhouse flowmeter is giving max output to the wall outlet.

Good feedback, thanks!!

Bighorn | 2020年1月23日

Sounds right, Haan

sbeggs | 2020年1月23日

Interesting thread!