Wiki Sudden Loss Of Range With 2019.16.x Software

[Evoforce]

So you gained a bit back?

Yes

 

[lightningltd]

Yes

Firmware version?

 

[David99]

The BMS on the old chemistry with veteran cars now works in favor of the weakest cell in the whole bunch of more than 7100.

That's always been the case. The BMS always has to use the weakest cell (in our case 'brick of 74 parallel cells') as the limiting factor when discharging for the entire pack. Once that brick is at the lowest point, discharging has to stop to prevent this one brick to drop below the lowest acceptable point. It doesn't matter that all other bricks are higher (have more capacity left). The same is true for the highest cell brick. Once that has reached the max voltage allowed while charging, charging has to stop to prevent this one brick from overcharging and catching on fire. It doesn't matter than all the other cell bricks could still take more charge.

Balancing is supposed to keep all bricks equal, but if one brick has issues, balancing can't fully compensate for it. By capping the top charge level well below true 100% Tesla makes sure none of the bricks gets even near the max voltage. Clipping off 10% might seem a lot and excessive. But imagine someone charging to 100% and then goes downhill and use regen a lot. When using regen the BMS allows the pack voltage to go to the maximum. But if one brick is higher than the others, that one brick will now get pushed beyond the max point.

So my theory is that in the affected cars there is at least one brick that has issues and has the potential to spike above the max 4.2 Volt in certain situations (either charging or regen) which causes serious damage. To be on the safe side Tesla capped the top 10% to make sure none of the bricks can possibly surpass the max.

 

[Evoforce]

Firmware version?

2019.24.4

 

[lightningltd]

2019.24.4

Interesting. I am on the same version and mine is still at 215 miles

 

[Evoforce]

Interesting. I am on the same version and mine is still at 215 miles

Hope it improves for you and the rest of us.

 

[lightningltd]

That's always been the case. The BMS always has to use the weakest cell (in our case 'brick of 74 parallel cells') as the limiting factor when discharging for the entire pack. Once that brick is at the lowest point, discharging has to stop to prevent this one brick to drop below the lowest acceptable point. It doesn't matter that all other bricks are higher (have more capacity left). The same is true for the highest cell brick. Once that has reached the max voltage allowed while charging, charging has to stop to prevent this one brick from overcharging and catching on fire. It doesn't matter than all the other cell bricks could still take more charge.

Balancing is supposed to keep all bricks equal, but if one brick has issues, balancing can't fully compensate for it. By capping the top charge level well below true 100% Tesla makes sure none of the bricks gets even near the max voltage. Clipping off 10% might seem a lot and excessive. But imagine someone charging to 100% and then goes downhill and use regen a lot. When using regen the BMS allows the pack voltage to go to the maximum. But if one brick is higher than the others, that one brick will now get pushed beyond the max point.

So my theory is that in the affected cars there is at least one brick that has issues and has the potential to spike above the max 4.2 Volt in certain situations (either charging or regen) which causes serious damage. To be on the safe side Tesla capped the top 10% to make sure none of the bricks can possibly surpass the max.

It is kind of odd that they did not add the logic to stop the charge to an individual module if it is at max and continue charging the others that are not. Don't they have the ability to take one module offline if there is a malfunction? The same for discharging as well.

 

[mjmiron]

Or they can replace our f’up batteries

 

[EK123]

2015 P85D - no loss of range, been at 243 for some time now.

But supercharging is handicapped - takes about twice as long. Monday, approx 65F started taper very early compared to a month ago. Last nights 2019.28.2 didn't change anything related to charging that I could tell. Will cost me an hour on the drive home tomorrow.

49 miles, 102kW
75 miles, 87 kW
119 miles, 65 kW
159 miles, 48 kW
177 miles, 43 kW
193 miles, 39 kW

this morning:
142 miles, 51 kW
186 miles, 36 kW
Also early morning and 60 degrees.

I was the only car at the supercharger each time.

I love my car, but this has changed functionality and makes traveling painful.

I made an appointment on the app. Got an email looking for details. Then appointment was just canceled.

I presume there is an update coming with some level of function to return, but there are better ways to handle what's going on. . .

 

[DJRas]

That's always been the case. The BMS always has to use the weakest cell (in our case 'brick of 74 parallel cells') as the limiting factor when discharging for the entire pack. Once that brick is at the lowest point, discharging has to stop to prevent this one brick to drop below the lowest acceptable point. It doesn't matter that all other bricks are higher (have more capacity left). The same is true for the highest cell brick. Once that has reached the max voltage allowed while charging, charging has to stop to prevent this one brick from overcharging and catching on fire. It doesn't matter than all the other cell bricks could still take more charge.

Balancing is supposed to keep all bricks equal, but if one brick has issues, balancing can't fully compensate for it. By capping the top charge level well below true 100% Tesla makes sure none of the bricks gets even near the max voltage. Clipping off 10% might seem a lot and excessive. But imagine someone charging to 100% and then goes downhill and use regen a lot. When using regen the BMS allows the pack voltage to go to the maximum. But if one brick is higher than the others, that one brick will now get pushed beyond the max point.

So my theory is that in the affected cars there is at least one brick that has issues and has the potential to spike above the max 4.2 Volt in certain situations (either charging or regen) which causes serious damage. To be on the safe side Tesla capped the top 10% to make sure none of the bricks can possibly surpass the max.

The regen power allowed is as controlled as DC Supercharging. So, likely that no spikes above 4.2 volts there either. Certainly not over 0.1 volt more.

 

[DJRas]

It is kind of odd that they did not add the logic to stop the charge to an individual module if it is at max and continue charging the others that are not. Don't they have the ability to take one module offline if there is a malfunction? The same for discharging as well.

No, they have no control over individual bricks.

 

[egn1]

T
The BMS doesn't work for a single cell of the 7104, ...

Actually partly it does, because if one cell has lower capacity or higher IR than others the brick voltage will rise faster at charging and reach the termination voltage earlier, and will also fall faster and cause shutdown earlier.

Balancing doesn't help much here, because cells are balanced only at the current voltage of current SOC, and the balancing current is much to small for compensation on typical currents during driving and charging.

 

[egn1]

Clipping off 10% might seem a lot and excessive. But imagine someone charging to 100% and then goes downhill and use regen a lot.

Regen is limited to a value so that no cell surpasses 4.20 V.

 

[Moorebid]

Regen is limited to a value so that no cell surpasses 4.20 V.

Or 4.07 V, now.

 

[Ferrycraigs]

2015 P85D - no loss of range, been at 243 for some time now.

But supercharging is handicapped - takes about twice as long. Monday, approx 65F started taper very early compared to a month ago. Last nights 2019.28.2 didn't change anything related to charging that I could tell. Will cost me an hour on the drive home tomorrow.

49 miles, 102kW
75 miles, 87 kW
119 miles, 65 kW
159 miles, 48 kW
177 miles, 43 kW
193 miles, 39 kW

this morning:
142 miles, 51 kW
186 miles, 36 kW
Also early morning and 60 degrees.

I was the only car at the supercharger each time.

I love my car, but this has changed functionality and makes traveling painful.

I made an appointment on the app. Got an email looking for details. Then appointment was just canceled.

I presume there is an update coming with some level of function to return, but there are better ways to handle what's going on. . .

Unfortunately, this is a separate issue. The restricting of batteries (sometimes called batterygate) appears to have been triggered by 2019.16.1.x and seems to only affect some pre facelift 85s and below. Not all cars, just some, and we don’t know why some are targeted yet others aren’t.

The restriction on charge speed (sometimes called chargegate) seems to have been from 2019.20.4.2 and seems to affect all models of cars from the whole fleet, but again not all of them. And again we don’t know why some and not others.

You seem to be suffering from chargegate.

 

[Droschke]

You seem to be suffering from chargegate.

Condition C.

 

[mjmiron]

Has anyone had any success with the local SC to get their battery replaced or have them looking into the issue? Or are most of you getting the typical blow off we have all seen of its normal?

 

[Ferrycraigs]

Has anyone had any success with the local SC to get their battery replaced or have them looking into the issue? Or are most of you getting the typical blow off we have all seen of its normal?

I am now in an unbreakable circle of events.
I complain that my Capacity has been reduced.
They reply that Loss of Range or Energy is not covered under the Warranty
I clarify that I am not complaining about loss of Range, but Loss of Capacity.
They reply that Loss of Range is not cover under the Warranty.
I clarify that I am not complaining about loss of Range, but Loss of Capacity.
They reply that Loss of Range is not cover under the Warranty.

So I guess I am in the 'most of you' camp.

 

[MP3Mike]

I am now in an unbreakable circle of events.
I complain that my Capacity has been reduced.
They reply that Loss of Range or Energy is not covered under the Warranty
I clarify that I am not complaining about loss of Range, but Loss of Capacity.
They reply that Loss of Range is not cover under the Warranty.
I clarify that I am not complaining about loss of Range, but Loss of Capacity.
They reply that Loss of Range is not cover under the Warranty.

So I guess I am in the 'most of you' camp.

But the warranty doesn't talk about loss of range it talks about energy/capacity, and loss of capacity isn't covered:

The Battery, like all lithium-ion batteries, will experience gradual energy or power loss with time and use. Loss of Battery energy or power over time or due to or resulting from Battery usage is NOT covered under this Battery and Drive Unit Limited Warranty, except to the extent specified in this Battery and Drive Unit Limited Warranty.

I don't see range mentioned in the battery warranty section at all, they do mention battery capacity a lot of times though.

 

[BrownMS]

has 28.2 helped anyone?