Charging the Roadster

[markwj]

So newest data point: I put about 35-40 miles on it yesterday, brought it home, let it cool down, and then put the charger on it. (Standard mode, 120V, 15A on the yellow cable) This morning the display shows "Done Charging" and the port has blue light. (I think this means the charge was not interupted) The ideal range is now 101 and the battery icon looks like its at about 57%. So it appears this issue is getting worse as time goes on. Unless I'm misreading something... The plan is to leave it plugged in for the next couple of days and see if the wake up cycles balance the battery and bring up the ideal range.

I suggest you look at the ESS screen in the little diagnostics menu (1050 code). See what it shows for SOC%, MIN% and MAX%. If you have a big difference between MIN% and MAX% (more than 3% or so), your battery is out of balance and is the cause of the issue. The car's discharge (drive) is limited by MIN% (the brick with the lowest voltage), and the car's charge is limited by MAX% (the brick with the highest voltage). I suspect that this is your problem, and Gruber will be able to tell from the logs. My guess is that you will see MAX% in the high 80's%, after a standard charge that stops, and MIN% in the 50's%.

If the issue is simply that it is out of balance, then leaving it plugged into the charger after a full charge may help. But you will need to leave it there for hours/days. It can only re-balance a couple of percent a day.

However, the symptom you show, of the charge stopping earlier and earlier each time you drive/charge, is more likely to be caused by one or more bad bricks in the battery. Gruber can help you with that, while Tesla won't be able to do much.

 

[Electric Swede]

I suggest you look at the ESS screen in the little diagnostics menu (1050 code). See what it shows for SOC%, MIN% and MAX%. If you have a big difference between MIN% and MAX% (more than 3% or so), your battery is out of balance and is the cause of the issue. The car's discharge (drive) is limited by MIN% (the brick with the lowest voltage), and the car's charge is limited by MAX% (the brick with the highest voltage). I suspect that this is your problem, and Gruber will be able to tell from the logs. My guess is that you will see MAX% in the high 80's%, after a standard charge that stops, and MIN% in the 50's%.

If the issue is simply that it is out of balance, then leaving it plugged into the charger after a full charge may help. But you will need to leave it there for hours/days. It can only re-balance a couple of percent a day.

However, the symptom you show, of the charge stopping earlier and earlier each time you drive/charge, is more likely to be caused by one or more bad bricks in the battery. Gruber can help you with that, while Tesla won't be able to do much.

Looking at the SOC it shows: LIM 41% MIN 41% MAX 85%
Is the best way to balance the battery is charge it at 240V 24A and let it sit for a while?

 

[hcsharp]

Looking at the SOC it shows: LIM 41% MIN 41% MAX 85%
Is the best way to balance the battery is charge it at 240V 24A and let it sit for a while?

I feel like a doctor who has to inform their patient that they have cancer. I'm sorry but It looks to me like you have a bad brick or sheet. Gruber is good at battery chemotherapy. Don't worry, this has a 99% chance of recovery. It's just expensive and time consuming, that's all.

 

[jason.tv]

Looking at the SOC it shows: LIM 41% MIN 41% MAX 85%
Is the best way to balance the battery is charge it at 240V 24A and let it sit for a while?

By the time your logs are reviewed from gruber will be few more days and your car could be even lower battery state; Either way, even if you take it to tesla service center someone prob won't be able to look at your car until a roadster specialist makes scheduling by then your battery will have no state of charge.

imo I would say charge with the 240v 24-32a instead of letting your battery drain. I'm not an expert or know 100% on this matter but these are my thoughts.

 

[markwj]

Looking at the SOC it shows: LIM 41% MIN 41% MAX 85%
Is the best way to balance the battery is charge it at 240V 24A and let it sit for a while?

Henry says it well. In all likelihood you have at least one bad brick; the difference between MIN% and MAX% is just too large to be explained by a normally out of balance pack. The logs will tell you the exact story (send them to me, mark (at) openvehicles (dot) com, if you want a second opinion).

The issue is that the car can only charge the entire pack; so once one brick hits the high voltage limit, charging has to stop. In your case, at least one brick has a significantly lower voltage when the highest brick hits the high voltage limit. Similarly, when you drive, the car has to discharge the entire pack; so once one brick hits the low voltage limit, driving has to stop.

Your car's ESS (big battery) is made up of 11 sheets, with each sheet having 9 bricks (totally 99 bricks in the pack). Each brick has 69 individual cells wired together.

In cases like yours, normally one or more bricks are bad - they won't take a charge properly. Sometimes this gets worse and worse every time you charge/discharge. The fix is either to replace the sheets containing the bad bricks, or in some cases one particular bad cell in the brick can be identified and literally cut out of the circuit (leaving the other 68 cells in the brick to take the load). Either way, the ESS has to come out of the car. Better to get it done earlier, rather than later, to avoid further damage.

Gruber has by far the most experience with doing this sort of work in the USA.

 

[Electric Swede]

I'm the kind of person who can take bad news, so if she has cancer I won't cry....in front of any of you. Seriously though, I understand the situation and appreciate the help Mark, Jason, and Henry.

Maybe, just maybe there is a little good news here. This morning I woke up to find the power to my house went out again last night. (Like I said earlier, this happens around here more than it should. My microwave has no time and my range is flashing "FP" so I know the whole house lost power. I only tell you this because this proves it isn't the charging cable nor the circuit I'm charging on. And I'm not sure where the car would have actually charged to had it completed a charging cycle.) When I checked the car this morning it does not say "Done Charging" and the charge port is glowing blue, wich makes sence since the power was interupted. However the LIM is now 43%, the MIN is also 43% and the MAX is 89%. Someone said if the battery is out of balance it will take a long time to correct itself at 120V 15A because it can only recover at 1-3% per day/charge. Does the increase in LIM and MIN by 2% (yesterday they were at 41%) mean the battery might be recovering and with more cycles it might come back?

Would a Range Charge at 240V 32A help (or hurt) at this point? Gruber has my logs but I don't know how long it will take them to get back to me.

 

[Bunnak]

Take it to Gruber and call it a day. Anything else besides the PEM or battery I'll let Tesla deal with. This appears to be a battery problem.

 

[markwj]

Does the increase in LIM and MIN by 2% (yesterday they were at 41%) mean the battery might be recovering and with more cycles it might come back?

I doubt it (having seen the logs, and the state of that brick). The individual cells in the brick are connected in parallel and should have the ability to effectively charge each other within the brick itself. It is highly unlikely that all the cells in the brick failed at the same time in the same way - more likely that one cell failed, is refusing to take a charge, and is pulling the others down to it's level. If the other cells in the brick can't bring it up, then it is unlikely that charging will have much of an effect.

Fundamentally, the car only has the ability to charge all the bricks, or discharge them on an individual basis (aka 'balancing'). The way balancing works is that you charge the car until it stops charging (max brick at target voltage) and leave it that way. Don't unplug or turn off the power. The car will then go through its 'balancing' process (that you can monitor on the balancing screen in the diagnostics on that little VDS - the screen with a bunch of 1's and 0's. If you look at that screen on your car, you should be able to clearly see the faulty brick (the odd one out).

For example, let's say you have 98 bricks at 3.9V and 1 brick at 3.1V. The car will then start bleeding power from each of those high 98 bricks, using comparatively small switchable resistors on each brick. Say after 24 hours, those 98 bricks are now at 3.8V (and the 3.1V brick is unchanged). So, now the car charges and brings back those 98 bricks to the limit of 3.9V but also brings up the one low brick to 3.2V. Repeat the process for several days, and the battery would slowly come back into balance.
(the voltage numbers above are not the actual limits, but just used for demonstration purposes)

Would a Range Charge at 240V 32A help (or hurt) at this point? Gruber has my logs but I don't know how long it will take them to get back to me.

I doubt it. I've seen that tried on a few cars in a similar situation to yours, but it made no difference.

What you need to do is bring the voltage up on that one brick, but the only way to do that is to bring the voltage down on all the others and then charge them all up together (aka balancing). However, in your case it is likely that cells in that one brick are damaged and won't take a charge.

I don't see much harm with leaving it connected 24/7 to a charger, and seeing if it will balance. But I doubt if it will have much of an impact.

 

[Electric Swede]

So what does the MIN % mean? I thought it was the maximum the car would charge the battery based on the lowest brick. If this is the case, and the MIN % increases doesn't that mean the battery is "recovering" from whatever out-of-balance it was in?

If it is not the case that the MIN % is the maximum the car will charge the battery, then what does it mean?

Additionally, when the car is not charging I see all 1s and one 0 on the VDS when I pull it up. However, when I pull up the VDS while the car is charging I see all 0s and no 1s. What does that screen tell me when I see 1s or 0s?

 

[Electric Swede]

BTW - I heard back from Peter Gruber and he said the car has "a resistive brick, #96. The decline started Saturday evening on June 13th and has been declining since." So it appears, as Henry suspected, it is cancer. The good news is it's only Stage 1 based on the fact that "your affected brick has not dropped below 2.5V," according to Peter. It looks like my little baby will be taking an unscheduled trip to the Sonoran desert.

Interesting note: I suspect Brick #96 has been an issue for a lot longer than 13 June. When I check the 1s and 0s (as in the post above) #96 is the one that would show the 0 when the others were 1s. It has been like this since I got the car 1 1/2 years ago. That is assuming the numbering scheme on the 1-9 and 1-b grid reads down the columns and then from left to right. The 0 has always shown up at row 6, column b, which by my math is number 96. If this is correct, maybe the 3 1/2 months sitting at the body shop exacerbated the issue that I suspect has been building (or lying in wait) for a while.

 

[markwj]

So what does the MIN % mean? I thought it was the maximum the car would charge the battery based on the lowest brick. If this is the case, and the MIN % increases doesn't that mean the battery is "recovering" from whatever out-of-balance it was in?

If it is not the case that the MIN % is the maximum the car will charge the battery, then what does it mean?

Additionally, when the car is not charging I see all 1s and one 0 on the VDS when I pull it up. However, when I pull up the VDS while the car is charging I see all 0s and no 1s. What does that screen tell me when I see 1s or 0s?

The MIN% is the SOC of the brick with the lowest voltage. It controls how far the car can be driven (until MIN% is 0).

The MAX% is the SOC of the brick with the highest voltage. It controls how much the car can be charged (until MAX% is the limit).

So, if your MIN% increased 2% that would indicate it 'got better', and managed to charge to a slightly higher voltage than before. However, 2% is probably not significant, given normal charging variances and the fact the brick is faulty.

On the balancing display, a '1' means it is discharging that brick, and a '0' means it is not. Your display of all 1's and one 0 on the VDS would indicate the car is discharging all the bricks except one (the faulty one), in order to try to balance the pack. The car is trying to bring down all the other bricks to the same voltage as the lowest one. Balancing only occurs after the car has completed a charge, so all 0's when charging is expected.

 

[dhrivnak]

I may be off here but assuming it may be a while before you can ship to Gruber; charge in range mode. And somewhere north of 95% stop the charge and let the balancing work it’s slow magic. Check every day or so and when the top brick (max) drops to around 85% repeat to see if you can bring up the bad brick. This will take days but if you have days to burn while waiting for a transport I am not sure you have anything to lose.

 

[markwj]

BTW - I heard back from Peter Gruber and he said the car has "a resistive brick, #96. The decline started Saturday evening on June 13th and has been declining since." So it appears, as Henry suspected, it is cancer. The good news is it's only Stage 1 based on the fact that "your affected brick has not dropped below 2.5V," according to Peter. It looks like my little baby will be taking an unscheduled trip to the Sonoran desert.

I agree.

Interesting note: I suspect Brick #96 has been an issue for a lot longer than 13 June. When I check the 1s and 0s (as in the post above) #96 is the one that would show the 0 when the others were 1s. It has been like this since I got the car 1 1/2 years ago. That is assuming the numbering scheme on the 1-9 and 1-b grid reads down the columns and then from left to right. The 0 has always shown up at row 6, column b, which by my math is number 96. If this is correct, maybe the 3 1/2 months sitting at the body shop exacerbated the issue that I suspect has been building (or lying in wait) for a while.

From the logs I saw, the minimum voltage brick has been changing over time (which is good), but it locked onto #96 and hasn't changed since mid June. Here are some example over time:

12/07/2019 8 brick min
12/07/2019 73 brick min
12/07/2019 31 brick min
12/07/2019 20 brick min
...
12/12/2019 8 brick min
12/12/2019 19 brick min
12/12/2019 28 brick min
12/12/2019 11 brick min
12/12/2019 8 brick min
12/12/2019 19 brick min
12/12/2019 28 brick min
12/12/2019 20 brick min
12/12/2019 19 brick min
12/12/2019 56 brick min
...
01/04/2020 2 brick min
01/04/2020 8 brick min
01/04/2020 73 brick min
01/04/2020 74 brick min
...
01/15/2020 11 brick min
01/15/2020 8 brick min
01/15/2020 19 brick min
01/15/2020 5 brick min
01/15/2020 28 brick min
...
02/15/2020 20 brick min
02/16/2020 73 brick min
02/16/2020 74 brick min
...
03/22/2020 73 brick min
03/22/2020 74 brick min
...
06/13/2020 74 brick min
06/13/2020 73 brick min
06/13/2020 96 brick min
...
06/14/2020 74 brick min
06/14/2020 96 brick min
...
06/15/2020 96 brick min
06/20/2020 96 brick min
06/21/2020 96 brick min
06/22/2020 96 brick min
06/23/2020 96 brick min
06/24/2020 96 brick min
06/27/2020 96 brick min
06/28/2020 96 brick min
06/29/2020 96 brick min
06/30/2020 96 brick min

You can see it jumping around (which is good, and expected), but from 15th June #96 is locked as the lowest brick. The first time the logs show #96 as lowest brick was 06/13/2020.

 

[Electric Swede]

The MIN% is the SOC of the brick with the lowest voltage. It controls how far the car can be driven (until MIN% is 0).

The MAX% is the SOC of the brick with the highest voltage. It controls how much the car can be charged (until MAX% is the limit).

So, if your MIN% increased 2% that would indicate it 'got better', and managed to charge to a slightly higher voltage than before. However, 2% is probably not significant, given normal charging variances and the fact the brick is faulty.

On the balancing display, a '1' means it is discharging that brick, and a '0' means it is not. Your display of all 1's and one 0 on the VDS would indicate the car is discharging all the bricks except one (the faulty one), in order to try to balance the pack. The car is trying to bring down all the other bricks to the same voltage as the lowest one. Balancing only occurs after the car has completed a charge, so all 0's when charging is expected.

This is great information. (I knew I would eventually figure out how this car works.) So does it matter when I check the SOC? Obviously checking the balance while the car is charging is worthless. But what about the SOC MIN and MAX? I put the car on Range Charge after talking to Peter and just checked the SOC. Now I see MIN 47% and MAX 98%, which leads me to believe (maybe faulty logic) that the situation is getting better. When I started paying attention the MIN was 41%, then it went to 43%, and now it's at 47%. That sounds like improvement to me. However, this only holds true if the SOC reading doesn't matter if the car is charging or not.

I know, I know, there are those out there who are saying to themselves, "This guy is a 100 percent TOTAL optimist." And maybe so. I just know brick #96 has been the weak link in this battery for a while and maybe there's a chance...

 

[markwj]

So does it matter when I check the SOC? Obviously checking the balance while the car is charging is worthless. But what about the SOC MIN and MAX? I put the car on Range Charge after talking to Peter and just checked the SOC. Now I see MIN 47% and MAX 98%, which leads me to believe (maybe faulty logic) that the situation is getting better. When I started paying attention the MIN was 41%, then it went to 43%, and now it's at 47%. That sounds like improvement to me. However, this only holds true if the SOC reading doesn't matter if the car is charging or not.

An optimist is often disappointed, while a pessimist can only be pleasantly surprised...

I suggest checking the SOC after the charge has completed and stopped normally. That should give you an indication of the SOC that can be achieved. SOC is an algorithm largely based on voltage levels in the battery. It is an estimate, not an absolute.

The SOC value in the roadster is a little weird, as it is normalised to the 0-100% range, depending on the mode (standard, range). The DIAG ESS screen will show you the actual (not normalised) SOC. Basically range mode SOC. So when it says MIN 47%, MAX 98%, that is presumably after a full range mode charge?

When you charge in range mode, the cells are allowed to go to a higher voltage limit (when compared to standard mode). The fact that your min brick charged to a higher voltage (as indicated by higher SOC) is a good thing. But remember you probably only have 1 or 2 bad cells in a brick of 69 cells, so don't read too much into it.

If you were previously seeing 41%/85%, that is 2.07 times difference. Now, 47%/98% is 2.09 times difference. So, a little bit worse (but probably not significant). In an ideal world, with a balanced battery, MAX% and MIN% should be the same - or at least within a couple of percent of each other.

 

[Electric Swede]

Psychologists will tell you there are five phases of grieving: Denial; Anger; Bargaining; Depression; and Acceptance. Although that is a normal progression, not everyone goes through all phases after a loss. I have finally come to the acceptance phase of my little Roadster’s fate. I think I actually skipped the depression phase, but I’m not a depressive kind of guy anyway. After trying more times than I probably should have to revive her, I have finally pulled the plug (literally) on #0681. The final range charge only went to 68 miles before it stopped charging and the charge port started glowing green. Brick 96 has turned out to be her Achilles heel. I am already arranging for the trip to Phoenix where I will let the Gruber bunch do their magic and rid her of this terrible plight. I send a big “Thank You” to all who tried to help, gave advice, and prayed that #0681 would not succumb to this condition, but alas, she has. I’m not sure when I will see her again, but I will keep you posted on any updates as they come in.


By the way, either the statement that pulling the ESS Pack Service Disconnect “requires a contortionist to unplug, or a skinny teenager with long arms” is overstated or this 57-year old guy is a contortionist, or he has the arms of a skinny teenager. I’m not sure which is correct but I didn’t find it all that hard to unplug. In fact, I had to plug it back in and then unplug it again because I left the windows down before the first pull.

Thanks again everyone.

 

[Electric Swede]

#0681 is packed and ready for her trip to Gruber's in Phoenix.

I had an interesting time getting her out of the garage today. I pulled the ESS By-Pass three weeks ago, as per instructions from Pete Gruber and hoped it would have enough juice left in the ESS to allow me to drive it onto the trailer. Well that didn't happen... And she wouldn't go into Tow Mode the last time I tried, so I was in a bit of a pickle. This morning I pulled the trickle charger off the 12V battery and put the wheel well back together. After re-inserting the ESS By-Pass plug I opened the charge port door and got a white light, then plugged in the charging cable and got a blue light: So far, so good. I then told it to start charging right away and at first it looked like it was going to work, but in 30-45 seconds I got the message that it aborted charging and got a red light in the charge port. I called Pete and he said if I pull the ESS By-Pass, waith 5-10 minutes then plug it back in, I should have a minute or so to put it into Tow Mode before the car realizes how low a state the battery is in and won't do anything else. Pete said there is power in the battery but it is so depleated that the car can't do anything but wake up, but I might be able to get it into Tow Mode before the car realizes it so I only have about a minute or so to do it. He said if it didn't work, try it a couple more times. And if that didn't work, call a tow truck and ask them if they can get it on the trailer for me. So Pete's technique didn't work the first time. And it didn't work the second time. And... it still didn't work the third time. After calling five different tow truck companies I started doing something that it seems not a lot of people do nowadays, and that was start thinking. So after thinking about this while waiting for a tow company to call me back I had an idea...and what would it hurt if it didn't work, right?

So I waited 10 minutes since I pulled the ESS By-Pass plug, plugged it in again and tried to get the car to go into Tow Mode. I was pretty sure this wasn't going to happen since it didn't work the last three times I tried it, but this was only the first half of my idea. Once it said it wouldn't go into Tow Mode because it needes APS, I plugged in the power cable. That gave me a blue light like I got earlier in the day and I jumped in the car to tell it to charge right away. This time I got a message on the MFD that said the car can't charge while in Tow Mode, so I exited that screen and went into trying to put it in Tow Mode. This time I heard the clunk and knew I had tricked it into grabbing just enough power from the ESS it needed to give me what I needed. Letting off the E-brake and three houses on either side of me all knew the car was free rolling!

To get the car up on a U-haul Auto Transport, I need to use some ramp extentions and front wheel platforms to keep the lower parts from hitting the front of the trailer. My Porsche also needs these so I already have them in my garage. With the help of a next-door neighbor and a come-along we got #0681 up on and snuggly strapped down to the AT. The more astute of you notice the 'T's on the side of the car used to be black but are now red. Needing to replace the passenger side after the body work, I decided to go with red this time around. The little white Roadster is on the trailer and the plan is to drive it to Gruber over the next coulpe of days. I will keep you posted on the progress. I guess if you aren't interested, don't read. l0l

 

[Roadster]

Nice MacGyvering! Best of luck and here's to a full recovery for #681.

 

[racevpr]

This particular Roadster had one of 6,831 cells starting to die and typical symptoms are a gradual range decline as the offending cell drags down the rest of the cells in a brick.

As with all Roadster battery issues, time is of the essence and if caught early, the Roadster battery pack can be revived and repaired.

Here is an example of a Roadster that was delivered yesterday, bricked by the time it arrived, and is now on its way to recovery.

 

[Jodro]

Hi there, I'm the new owner of Roaster 919 in Ottawa, Canada (original owner was Doug_G) and I'm having some trouble charging the car. I'm new at this, I've never had an electric car nor a Roadster and I'm not sure if I know how to properly charge the car Please let me know if this is not right thread to use for this. So here's the story:
- I bought the car two weeks ago and moved it on the road. The battery started full in range mode and I was able to drive over 200 km (about 125 miles) before stopping to charge. I charged at a Tesla destination charger and was able to charge for about 45 minutes before I got this error code: "ID 1084 DMC FW: HCS Faulted Warning". I tried another destination charger without more success. I was still able to get the car to its final destination and at that point, I was able to charge the battery using a my Roadster cable (two cables see picture), the first ones plugged into a Tesla Connector finally plugged into a 120v regular outlet.
- Since then, it's been a hit and miss trying the charge the car: sometimes it works, sometimes it doesn't (always using the Tesla Connector plugged into the 120v regular outlet). When it doesn't, I'm still getting this error code: "ID 1084 DMC FW: HCS Faulted Warning". As I understand that this may be related to an "external charger problem", I ordered a Henry Sharp Can SR (thanks Henry!) to replace the two cables in the picture hoping this will fix the problem.
- Once, I was able to charge the car overnight and the following day, I got a new error message: "ID 279 BSM: Precharge resistor too hot at start of precharge". I was still able to charge a few times after this. When I can't, I've also noticed that the Tesla Connector while having its green light on, its red light will flash three times. According to the Tesla Connector manual, it means "Charging current is reduced due to high temperature detected in the Mobile Connector controller".
- I also tried changing the amperage the car will take to 15A (I've charged most of the time with it at 70A) without success.
- I had a Tesla technician coming at home trying to pull the car log: after a few hours, he gave up and I haven't heard back ever since. I'm trying to pull the log on my own in the meantime.

Any advice on what I can do next? Will the Henry Sharp CAN SR fix my problem or I am looking at something else? Any help is appreciated. Thanks