2023 Model 3 has not awaken in almost 5 days to top off the LV battery, normal?

[rrolsbe]

Good that it cross-checked well with the battery monitor.

The battery monitor is great; may be time to rig it up on the 16V. Seems like the only way to really know for sure.

Two miles over 6 days is about 3W so it does seem to suggest potential reduction in sleep power.

However, the first sleep cycle should be neglected (due to BMS adjustments). So hard to say. And possibly adjustments could occur on any cycle, I guess.

It does seem like it would have been low-hanging fruit for them to reduce sleep power. Curious whether they did.

Here is a little more information regarding phantom drain with the new 16V lithium battery.

I did not have the frunk open for 6 days and 14 hours the car was parked and sleeping so could not record the voltage over time but did gather voltage readings during the next parked session.

The voltage reading were as follows:

15.5V right after the HV contactors opened
15.44V five hours later
15.33V 24 hours after the 15.44V reading

So the voltage dropped approx 0.11V in the first 24 hours this voltage drop will probably not be linear over several days as the voltage drops.

The spec on the 16V battery is 6.9ah with a capacity of 99wh. Given this 99Wh capacity the average power draw over the 158 hours period was less than 1W. I am not normally parked for six plus days but will try to record voltage readings for more than 1 day. Note: the power draw on my 2018 Model 3 was around 6 to 7 watts.

Not sure if Tesla is or can use the entire 99Wh battery capacity? what is the top percent SOC when fully charged? bottom SOC when top off is initiated?

Bottom line, power usage while parked is in the noise.

Comments and additional technical information welcome.

PS, Given the low sleeping power draw, connecting my Blue Tooth Battery monitor would probably reduce the 158 hr sleep time. Not sure if I believe the 1ma spec for the Battery monitor? I will probably only connect it when the car is doing something strange in the future to help with diagnostics.

Regards

 

[AlanSubie4Life]

Given the low sleeping power draw, connecting my Blue Tooth Battery monitor would probably reduce the 158 hr sleep time. Not sure if I believe the 1ma spec for the Battery monitor?

I would guess it's fine and could be a legit spec for a BLE-type device. 16mW from a 99Wh battery is 257 days so not too big an impact to hook it up assuming the spec is legit. Only one way to find out!

Bottom line, power usage while parked is in the noise.

Went from 239 Miles/82% to 237 Miles/81%..

Yes, it does seem low. Suggests that this 239 to 237 was partly re-estimation and not drain (since 1W would have drained less than 1 mile over that interval).

Anyway, seems potentially very low, and finally at the level it should have been when Model 3 first arrived. 1W is still quite high as cars go of course, but no longer an actual issue, and what was proposed (by people complaining about this) as a reasonable level years ago. And people said it was important to have several watts to run all the radios - makes no sense!!! Assuming 1000 cycles of the 99Wh are achievable (might be quite possible depending on the cell type & discharge patterns), that gives 11 years of life. Hopefully they're targeting more like 20 years.

Interested to hear if you ever get another long interval to check this, to see whether this 1W draw can be duplicated. No one seems to complain about the drain much anymore, so it does seem like something has improved.

 

[rrolsbe]

There is some good information regarding the new 16V lithium LVB.

The spec indicates it can charge at a rate of up to 10C, 6.9A X 10 = 69A
also states it can be charged down to -10C/14F

I assume it can not be charged at a 10C rate at a temp of -10C

The discharge spec is up to 50C, 50 X 6.9A = 345A
spec shows the lowest temp it is allowed to discharge at is -20C/-4F

Also assume it can not be discharged at a 50C rate at a temp of -20C

Must be a chart somewhere showing the C rate version temp for charging and discharging?

Looks like no battery heater. So if temp is below -10C it will discharge to warm the battery to -10C before charging can begin.

I thought the car was designed to be functional down to -20F? Would the car not close the contactors at -4F and below?

The min/max shown in the spec sheet are probably different than what is actually allowed by the BMS. I think the specs are for the CTLA packs themselves.

 

[rrolsbe]

Here is a little more information regarding phantom drain with the new 16V lithium battery.

I did not have the frunk open for 6 days and 14 hours the car was parked and sleeping so could not record the voltage over time but did gather voltage readings during the next parked session.

The voltage reading were as follows:

15.5V right after the HV contactors opened
15.44V five hours later
15.33V 24 hours after the 15.44V reading

So the voltage dropped approx 0.11V in the first 24 hours this voltage drop will probably not be linear over several days as the voltage drops.

The spec on the 16V battery is 6.9ah with a capacity of 99wh. Given this 99Wh capacity the average power draw over the 158 hours period was less than 1W. I am not normally parked for six plus days but will try to record voltage readings for more than 1 day. Note: the power draw on my 2018 Model 3 was around 6 to 7 watts.

Not sure if Tesla is or can use the entire 99Wh battery capacity? what is the top percent SOC when fully charged? bottom SOC when top off is initiated?

Bottom line, power usage while parked is in the noise.

Comments and additional technical information welcome.

PS, Given the low sleeping power draw, connecting my Blue Tooth Battery monitor would probably reduce the 158 hr sleep time. Not sure if I believe the 1ma spec for the Battery monitor? I will probably only connect it when the car is doing something strange in the future to help with diagnostics.

Regards

Did a few more experiments. Temporarily connected my 12V/16V battery monitor for a few days and found the following.

The current draw of the Battery Monitor is around 2.4ma varies up and down slightly. So much for the spec 1.5ma. So the power draw is around 15V X 2.4ma or 36mw.

With the monitor connected the voltage drop over a 24hrs period was about .2v as apposed to .1v not connected. Both of these 24hr readings were taken after the car had been sleeping for around four hours. Guess you could draw the conclusion that the car WITHOUT the monitor connected is only using an average of about 36mw of power while sleeping (almost unbelievable because it was around 6 to 7 watts for our 2018 Model 3!). Looks like the car will sleep for over six days without the monitor attached. Need to leave the monitor attached for a few weeks and see what happens. After a longer test period, I will probably only attach the monitor if the car is doing something strange.

When I get a chance, I will perform the tests again to see if the results are similar and monitor for a longer period.


.

 

[AlanSubie4Life]

The current draw of the Battery Monitor is around 2.4ma varies up and down slightly.

How did you measure this?

WITHOUT the monitor connected is only using an average of about 36mw of power while sleeping (almost unbelievable because it was around 6 to 7 watts for our 2018 Model 3!)

Doesn’t take a lot to run a receiver or an occasional low power transmitter! The 6-7W was completely nuts.

 

[rrolsbe]

How did you measure this?

Doesn’t take a lot to run a receiver or an occasional low power transmitter! The 6-7W was completely nuts.

With my multi meter connected in line. Could be possible the reading was not very accurate, maybe someone else with a BM could check their current draw?

 

[AlanSubie4Life]

With my multi meter connected in line. Could be possible the reading was not very accurate, maybe someone else with a BM could check their current draw?

Seems like at those low draws it would be reasonably accurate and in any case the result would likely be slightly low, if there was voltage drop introduced by the meter. I thought probably that's what you did but wasn't sure.

With the monitor connected the voltage drop over a 24hrs period was about .2v as apposed to .1v not connected.

Since I mostly believe your 36mW number, I guess as long as the 0.1V drop every 24 hours is pretty repeatable I would agree with your ~30-50mW conclusion. Doesn't really align with your 158-hour sleep time (that's only 6Wh or whatever out of 99Wh) but maybe something else is waking the car up (or it wakes up on a schedule of its own) and of course that will rapidly deplete the battery.

 

[rrolsbe]

How did you measure this?

Doesn’t take a lot to run a receiver or an occasional low power transmitter! The 6-7W was completely nuts.

I read somewhere the early Model S cars had a user selectable setting to put the car in a deep sleep which used less power during sleep. The only down side was it took something like 30 second for the contactors to close and the car to wake up.

 

[rrolsbe]

I read somewhere the early Model S cars had a user selectable setting to put the car in a deep sleep which used less power during sleep. The only down side was it took something like 30 second for the contactors to close and the car to wake up.

Update to info in this thread.

About a month back, according to EEVEE, the car started to wake randomly once or twice a day. I did see a small drop in the SOC so the EEVEE app appears to have been correct. I have performed some debugging and have yet to pinpoint what is causing the car to randomly wake up (might have stopped after a car firmware update). I configured the EEVEE app to stop retrieving data from the car and reconnected my Bluetooth battery to monitor the 16V battery voltage. Had a bad storm so the car was parked for seven days. At about the five day point the car woke to top off the 16V battery. Not sure what the 16V battery SOC was when the car woke but believe it can top off the charge in less than 30 minutes.

The 16V battery voltage went from approx 15.5V to 14.9V after five days. According to this video

the Mosfet will open to protect the 16V from damage when the voltage reaches 13.8V. Since the car woke when the voltage dropped to around 14.9V, there was still enough energy in the 16V battery to precharge the HV buss to allow the contactors to close (wake the car). Since the 16V battery BMS does not have a battery heater, there has to be enough discharge energy available, after the HV buss is pre-charged, to warm a very cold 16V battery enough to allow charging?

My 16V battery never gets cold enough to use the Service Menu to verify what happens when the 16V battery is too cold to allow charging. Maybe someone in a cold climate could verify and comment?