Automatic Charging Intervals

[EdisonFire]

Hi All, I've experienced an issue since roughly this past weekend. (March 13) I have a 2015 Model S 70D. It's been plugged in for the past few days. Used the car on Monday. I keep getting notifications that charging has started with car at 199 miles, stops charging at 202 miles. I have the car set for ballpark 90% charge. I get that a house thermostat set to 70 degrees as an example will kick on when thermostat drops to maybe 68 degrees. Makes sense. It doesn't seemingly make sense to start Tesla charging at a 2 or 3 mile loss of charge. Never did this until recently. Anyone experienced anything similar? This happens 5-6 times a day.

 

[DerbyDave]

My "new" 2020 LR+ seems to top up the charge occassionally when needed while plugged in. I am used to the wall connector supplying some current when I am in the car while it is plugged in, but this is lately a full power charge for a minute (or two at the most). It adds a couple of miles charge. Doesn't bother me, but seems to be a change.

 

[MorrisonHiker]

I noticed a similar pattern a couple of versions ago on my 2017 S100D. I thought the 12V battery might be going out so I had Tesla mobile service take a look at it. They came out and spent an hour running all sorts of diagnostics and checked the 12V but didn't find anything wrong. The issue went away but I don't know if it was a reboot or a new firmware update that fixed it.

 

[ShawnA]

Hi @EdisonFire ,

I have this problem on my wife's 2015 Model S 85 D.
I first started noticing it on 2021.4.11
On Monday March 15 it started and stopped 40 times... Roughly every 1/2 hour.
Start and stop mileage are all the same.
Tuesday March 16 applied 2021.4.12
It still stops and starts roughly every 1/2 hour. No mileage added.
I got a film of the behavior.
The current builds to 64 Amp which is the maximum setting in the car
as soon as it reaches 64 Amp the charge stops with no miles added...

Set up for a service call next Thursday.

Horrible sound as the contactors engage before the charge.
It sounds like a high amperage buzzer.
Check out the YouTube at 55 seconds for the buzzer sounds.
any ideas???

Shawn

 

[Gforce1]

Hi @EdisonFire ,

I have this problem on my wife's 2015 Model S 85 D.
I first started noticing it on 2021.4.11
On Monday March 15 it started and stopped 40 times... Roughly every 1/2 hour.
Start and stop mileage are all the same.
Tuesday March 16 applied 2021.4.12
It still stops and starts roughly every 1/2 hour. No mileage added.
I got a film of the behavior.
The current builds to 64 Amp which is the maximum setting in the car
as soon as it reaches 64 Amp the charge stops with no miles added...

Set up for a service call next Thursday.

Horrible sound as the contactors engage before the charge.
It sounds like a high amperage buzzer.
Check out the YouTube at 55 seconds for the buzzer sounds.
any ideas???

Shawn

Every 15 minutes the car wakes up and pulls 6-17kw from the wall. All those spikes in my pic are from the car. My house looks like someone is being electrocuted thanks to all my low voltage led lights on dimmers. Mobile appointment booked but I’m not hopeful they find anything. It’s been this way for about 8 months since the HW3 MCU2 upgrade. 2017 P100D S.

 

[ShawnA]

Hi @Gforce1 ,

What is the device that is showing/graphing your spikes???

Thank You,

Shawn

 

[Wol747]

Mine too - it never used to do this on/off/on every few minutes until a few weeks ago. My thread on this is:

Strange charging behaviour

After 2021.4.12 on my S I have an odd charging behaviour. At home I keep it plugged into the HVWC and the SOC set to 70%. After the update there is the usual clanking of contactors and fan whirring about every three or four minutes, the car charges for a minute or so then stops until the next...

email.teslamotorsclub.com

Constant starting the system and stopping it must not be good for the car, and it certainly doesn't sound pleasant! I've been painting in the garage these last few days and hearing everything wind up every few minutes is rather stressful.
They need to let the car cycle a few more % around the set figure - at present it's set so close that probably the very act of turning on takes the SOC down more than the offset on the set charge is.

 

[Gforce1]

Hi @Gforce1 ,

What is the device that is showing/graphing your spikes???

Thank You,

Shawn

www.Sense.com

It monitors the power usage and solar production in my house down to the millisecond level. Comes in handy for this because I can monitor if the car is sleeping or not without a third party app that Tesla would just blame the issue on when it’s clearly nothing to do with third party monitoring.

 

[ShawnA]

Hi @Gforce1 ,

Very nice - Thank You,

Shawn

 

[Gforce1]

Mine too - it never used to do this on/off/on every few minutes until a few weeks ago. My thread on this is:

Strange charging behaviour

After 2021.4.12 on my S I have an odd charging behaviour. At home I keep it plugged into the HVWC and the SOC set to 70%. After the update there is the usual clanking of contactors and fan whirring about every three or four minutes, the car charges for a minute or so then stops until the next...

email.teslamotorsclub.com

Constant starting the system and stopping it must not be good for the car, and it certainly doesn't sound pleasant! I've been painting in the garage these last few days and hearing everything wind up every few minutes is rather stressful.
They need to let the car cycle a few more % around the set figure - at present it's set so close that probably the very act of turning on takes the SOC down more than the offset on the set charge is.

Not only is it not good for the car it's also not good for the grid. Instead of the grid needing to maintain a low baseline it now has to be ready for these constant spikes in demand coming from the car every 15 minutes. So instead of needing to provide 2kw my demand is now 20kw due to a 60 second spike every 15 minutes. Kind of goes against Tesla's mission.

 

[Gforce1]

Quick update.... mine stopped pulling from the wall every 15 minutes. But that’s likely because the MCU is now dead. Both screens went black and the car stopped reporting battery level to the app. I can connect to the car through the app and control some stuff but that’s about it. Car drives still but won’t charge. Waiting to get her into service now. I think the MCU has been the issue all along and it finally gave out. For the record this is the MCU2 upgrade that gave out on me.

 

[ShawnA]

Hi @Gforce1 ,

Please keep us posted...
My wife's 2015 Model S 85 D got the MCU2 upgrade in August last year...
It was still charging every 15, 20, or 30 minutes until I unplugged it.

My theory is that lately the trigger mechanism for charging is off by a factor of 10...
Instead of waiting for a 1 mile drop or a 1% drop it charges on a 0.1 mile drop
or a 0.1% drop in charge state...
My reasoning is that I usually do not see a mile lost or added by these frequent charges.
Maybe someone with one of the spy "tools" can confirm my suspicions...

Shawn

 

[Wol747]

FWIW I have just finished a 3 day idle on my S. In the garage, no charger plugged in and no sentry mode or opening doors, checking with an app etc, the vampire drain was 7Km - works out at 2.3Km/day.
Frankly I wa surprised - I was expecting more than that.

 

[hikerockies]

I have two Model S that are both doing the same thing - 2014 Model S85 MCU1 and original battery pack (FW 2020.48.37.1), and 2017 Model S100D MCU2 (FW 2021.4.12). After charging is done, car starts drawing 1kW-5kW (I have charging rate limited to 20A at 240V) every 15 minutes for about 30 seconds. Both cars do this for 6-7 hours. When car starts drawing current I can hear the battery pump start up. This seems to not happen when garage is warm (above 45F). Yesterday was a warm day and neither car did this. Tesla mobile tech had speculated battery pump comes on keep the battery warm after charging which makes sense considering I can hear battery pump start up. This behavior started on both cars around 2020.48.* firmware. Blue line in the attached consumption graph shows power draw on the charger.

 

[Wol747]

It's GOT to be the 12v battery starting up the whole inverter/transformer cycling. I wonder if it's an early indication that the 12v can't hold a charge?

 

[howardc64]

2013 MS85 63k miles. Hearing car making more noises recently. Its the classic contactor+coolant pump+radiator louver vents. Seems like started after MCU1 eMMC recall replacement a couple of weeks ago. Tesla erased all my settings. Been slowly figuring how to regain previous behaviors/settings. DIY updated 3G->LTE module and fixed bubbled touch screen afterwards (probably unrelated to this issue) Running 2020.48.37.1 which I think is latest for my car. Charge limit set to about 70% SOC. Plugging in after a trip would steady charge up to the limit, then afterwards would periodically hear contactors/coolant/louver noise sequence.

Since SC erased my MCU1 profiles with eMMC recall replacement, I thought it had to do with waking up the car somehow (passive entry mode, leaving keyfob in the car (in garage), phone bluetooth connecting etc) Finally started suspecting some kind of charge cycling. Promising solution so far is setup scheduled charging (set to 6am for now). After setting this, car seems dead quiet while plugged in. Would be interesting to hear what others observe with scheduled charging. Probably similar to the unplugged solution but at least plugged in to top off to limit 1x/day.

This observation probably suggest it is not 12V battery related? 12V load is not any less by setting the schedule charge. My 12V is a couple of years/10-20k miles old. But of course the 12V gets wiped out pretty fast through constant deep cycling.

Only time the car fired up contactors+coolant pumps+vent louvers was when I opened the Tesla app on the phone.

BTW, M3 forum is also full of charge cycling issues recently as well. Maybe there is some common software bugs across the product line.