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i have a few ideas that if successfull could make the battery packs serviceable...we all know that the ultrasonic welding is out of reach for most of us, but i think there might be a way to splice the bus bars on the top....there is some talk of resistance values on the bus bars, but they are copper I believe, and copper is much more repairable than aluminum/copper ultrasonic welds...i intend to leave the welds alone and focus on the top portion of the buss.....From what i have seen..the CSE ribbons are delicate, but solderable...My replacement pouch cells should be showing up this week so I will know more in a few days....Its tragic that companies can make and sell produces like this that are designed to be discarded for what should be a very repairable problem
 

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Just an update on the progress....As it turns out..the Positive pole of the pouch battery is made up of aluminum and the negative appears to be a clad copper...where as the buss bars between the cells seams to be be made of a layered copper aluminum construction..After some searching, I discovered that aluminum is perfectly solderable with the right flux and solder and at low temps...This opens up the possability of making the join at the battery tab-bus bar connection where the original sonic weld occured....The solder and flux have been ordered and are on their way....should know more in a few days....
 

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Just an update on the progress....As it turns out..the Positive pole of the pouch battery is made up of aluminum and the negative appears to be a clad copper...where as the buss bars between the cells seams to be be made of a layered copper aluminum construction..After some searching, I discovered that aluminum is perfectly solderable with the right flux and solder and at low temps...This opens up the possability of making the join at the battery tab-bus bar connection where the original sonic weld occured....The solder and flux have been ordered and are on their way....should know more in a few days....
Sounds dangerous. If the connection is high resistance, the heating could drive the cell to thermal runaway turning the battery pack and car into a big ball of fire. Lithium-cobalt-metal-oxide cells burn like gunpowder if they go into thermal runaway.
 

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Actually.....the factory utrasonic welds are disturbingly small...its hard to believe, but all of the current flow goes through 5 small welds, each the size of a match head...along with the tab size itself, which is about the same thickness of an aluminum soda can.....The welds are very easy to separate with just a sharp thin blade...With this in mind..I encourage everyone working with Lipos to watch video of a lithium cell fire....it will scare you beyond belief...and that is the kind of caution we need to operate with in this new frontier...Too bad the Smart company didnt make the battery in the Nissan replaceable module format...So much more user friendly..
 

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Actually.....the factory utrasonic welds are disturbingly small...its hard to believe, but all of the current flow goes through 5 small welds, each the size of a match head...along with the tab size itself, which is about the same thickness of an aluminum soda can.....The welds are very easy to separate with just a sharp thin blade...With this in mind..I encourage everyone working with Lipos to watch video of a lithium cell fire....it will scare you beyond belief...and that is the kind of caution we need to operate with in this new frontier...Too bad the Smart company didnt make the battery in the Nissan replaceable module format...So much more user friendly..
Yes, from pictures I've seen, it is hard to believe that those thin tabs on the Smart pouch cells can carry more than 120 amps.
 

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That's why I don't consider the Smart hv batt to be repairable. Moving cells around is not a bolt-unbolt scenario as it is with other EVs. All I can see doing is jumpering over bad cells by soldering to the copper areas and using for a low power solar storage. The inverter draws a lot of amps so good luck.
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Sorry to tell you it is repairable and even easy if you know what todo. There are in maintime several solutions out even to replace single cells and also the reason of the dead of the current sensor is known. So even when you disconnect the sensor it could be the sensor already died during discharge phase. You early can see this after the stacks are recharged again as their voltage is used to run a small dcdc converter producing the necessary 12V ( ok in this case a little bit higher than 13V) which is used to power the measurement unit of BMS and also the current sensor. This voltage get to high by malfunction during to low voltage and addition reasons of the stacks. This kills the currentsensor and befor on a lower voltage level already cause the enter of the locked P18051C.

This is just the reason behind. No voodoo or killing modes. Also the 12V Battery issue in relation i described in another thread already. Also a feature and not a bug.
 

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Sorry to tell you it is repairable and even easy if you know what todo. There are in maintime several solutions out even to replace single cells and also the reason of the dead of the current sensor is known. So even when you disconnect the sensor it could be the sensor already died during discharge phase. You early can see this after the stacks are recharged again as their voltage is used to run a small dcdc converter producing the necessary 12V ( ok in this case a little bit higher than 13V) which is used to power the measurement unit of BMS and also the current sensor. This voltage get to high by malfunction during to low voltage and addition reasons of the stacks. This kills the currentsensor and befor on a lower voltage level already cause the enter of the locked P18051C.

This is just the reason behind. No voodoo or killing modes. Also the 12V Battery issue in relation i described in another thread already. Also a feature and not a bug.
By "stacks" are you referring to the 31-cell units? Or is it just the word you are using for the whole battery pack?
 

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The stack is the 31 cell unit with the CSE pcb on top and the cooling plate.
The battery uses 3 stacks in series to get the 3x31 cells in a 93s1p configuration. The 3 CSE pcb together with the box ( you call it BMS) and the current sensor build the whole thing called BMS.

The pcb inside the "BMS" is splitted in to isolated parts. One is powered by the 3 stacks in series and is just used for measurement of voltage, current via the 12V powered current sensor via LIN Bus and also measure the isolation resistance (TC1736) and the other bigger part handling the CSE via CAN and build the BMS functions (TC1797) and powered by the 12 V from 12 Volt battery. The CSEs are isolated and powered by the Stack voltage 31S1P and if the stacks are discharged by a special reason, the CSE could not communicate anymore with the BMS. This are the 3 failure entries. So no communication to stacks under normal circumstances you need to open the battery to at least charge them to start again. BMS will only allow to switch on contactors if all cells are at least on 3,0V.
All this relay on no addition failures like HW defect, P18051C, current sensor and many more.
 

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There are many. All have their advantange and disadvantage.
Some overlap the metal bracket connecting the cells and solder them on the flat surface.
Others clamp the cell on the surface on the original connection point with additional metal brackets and additional use special high silver filled adhesive for the remaining gaps. Others just solder with a special low melt solder.
other try to use a kind of spot welder. Original there us a ultra sonic methode as the spot welder did not bring the best performance. Good to know the surface of the cell flaps use a ultra thin isolating coating of plastic on top. This cause some remaining material in the interconnection, which could cause an issue afterwards.
For welding there is still the option for a issue if you not take of the CSE PCB before and then you need to fix also this. This seems more easy with soldering or even just add tiny metal screws.
So also there are several options.
 

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I will be looking at all options in the next few days...from what I have learned so far is that you need a powerful soldering iron as the aluminum wicks away the heat at a high rate...but with the right flux, the solder does take to it
 

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Sorry to tell you it is repairable and even easy if you know what todo. There are in maintime several solutions out even to replace single cells and also the reason of the dead of the current sensor is known. So even when you disconnect the sensor it could be the sensor already died during discharge phase. You early can see this after the stacks are recharged again as their voltage is used to run a small dcdc converter producing the necessary 12V ( ok in this case a little bit higher than 13V) which is used to power the measurement unit of BMS and also the current sensor. This voltage get to high by malfunction during to low voltage and addition reasons of the stacks. This kills the currentsensor and befor on a lower voltage level already cause the enter of the locked P18051C.

This is just the reason behind. No voodoo or killing modes. Also the 12V Battery issue in relation i described in another thread already. Also a feature and not a bug.
So for those of us who may be interested in a package solution, is there a full battery pack available to purchase? I once found a battery part number but it wasn't available to order.

Thanks. (Just trying to help someone I'm currently out $124.50 and no solution in site)...

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Sure seems like when the drive battery dies on the smart for all practical purposes it's dead. I don't think the average owner of the car wants to jump through a thousand hoops to try and revive it.
Think about it, we are just hearing about the members on this form and the problems they are having with their smarts. Not to mention the hundreds out there that this is happening to that they have no idea that this form exists.
 

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Sure seems like when the drive battery dies on the smart for all practical purposes it's dead. I don't think the average owner of the car wants to jump through a thousand hoops to try and revive it.
Very true. I can't help but wonder if towing to the repair shops causes some of the damage/codes I saw yesterday. I saw one for the crash sensor that worried me. The car was left with the key in the ignition, but off she claims, for two days. It was dead, just from that. Shrugs. Not sure I want to spend about three hundred or so more on software from the company I bought the VXDiag from. I'm having a horrible time getting the PIWIS 3 I bought from them back to working.

Plus to revive the charge some specialized battery charging equipment. The car is in a canyon with limited space to work. Access to power is from a long extension cord. Took my charger half a day to get the 12V to 99%....

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You tried and you gave it a lot more effort then a lot of people would have being pro bono. As far as the story of the key being left in the ignition in the off position, being responsible for draining the battery. I think is kind of far-fetched. There's more to the story I'm sure.
Hopefully you did learn something more about ev/eq smarts that you didn't know before and it turned out to be a learning experience. This is why I love modern ice cars you can leave them 6-8 months, throw in a new battery if needed and start them up no need to worry about it $27,000 battery dying.
 

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My take on this Smart Car situation....After purchasing a bricked ED3 a couple of months ago....only because this car is a 2016 with 40,000 km on it and is in very good condition..This gave me the opportunity to fulfill my electric vehicle itch that i have had for 40 years...The reason this particular ED3 failed , is because of hitting an object on the road which broke one of the cooling nipples off the battery pack...The car then went to the local Mercedes dealership where the only solution was to replace the HV battery to the cost of over $12000 dollars...this all because the plastic nipple,which by the way simply has 2 screws attaching it to the pack and could be replaced in under a half hour to the cost of a few dollars!!....Unfortunately, the Smart company made these as a compliance vehicle and never intended for them to have any kind of lifespan or serviceability...the ultimate in disposable appliances.. and would be happy to see everyone of these ED3s scrapped immediately....There might be a bit of hope in the fact that the Smart company has been sold to a Chinese manufacturer and they hopefully have a different approach to these iconic cars...I am continuing to work on the splicing of individual cells within the stacks and cannot report as to which method it the best yet...Cheers for now
 

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Ok a fast feedback, more details later.

As far as the story of the key being left in the ignition in the off position, being responsible for draining the battery. I think is kind of far-fetched. There's more to the story I'm sure.
Even i need to check this comment in detail i could tell you the idea of a key in the lock cause an issue is not too far away.
Very easy assumption, there is a extra line/signal in the wiring of the smart called something like KL15c. This line is powered on plugged in key Typical usage are e.g. radio which stays on even you switch of the ignition till you pull the key.
If this signal will not let the ecus go into standby mode (visible by the still illuminated P of gearswitch) you will run exactly in the known issue of a empty 12V battery by higher drain currents and automatic recharge of by the HV Battery and or brown out of KL30 which trigger indirect the continues try to recharge the 12V battery and internal in the hv battery drain current which could kill or at least empty the stacks.

By the way in Germany the HV battery could be replaced by Smart/MB. It means a replacement costs about 8000-9000 € in replacement of the old battery. Depending on actual availability of refurbed stacks and old stocked stacks in a temporary stock in Germany. But for sure this will stop because the original production line of the cells is gone. Only stack level is available on MB level internally. In shop only whole batteries in exchange are available.
Out of second life and old cars refurbed batteries are available on the other way. Here are all levels available but as mentioned not from MB, which could not offer warranty on this solutions.

2. Forget on DXdiag. They could not go in the necessary details if a battery has an issue. Here the cheapest way is to organise a pass tru xentry with a cheap jtag prot device on the offical way. Or ask the web for alternativ solutions.

All other are only for minor diagnosic but not to solve anything.
 

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My take on this Smart Car situation....After purchasing a bricked ED3 a couple of months ago....only because this car is a 2016 with 40,000 km on it and is in very good condition..This gave me the opportunity to fulfill my electric vehicle itch that i have had for 40 years...The reason this particular ED3 failed , is because of hitting an object on the road which broke one of the cooling nipples off the battery pack...The car then went to the local Mercedes dealership where the only solution was to replace the HV battery to the cost of over $12000 dollars...this all because the plastic nipple,which by the way simply has 2 screws attaching it to the pack and could be replaced in under a half hour to the cost of a few dollars!!....Unfortunately, the Smart company made these as a compliance vehicle and never intended for them to have any kind of lifespan or serviceability...the ultimate in disposable appliances.. and would be happy to see everyone of these ED3s scrapped immediately....There might be a bit of hope in the fact that the Smart company has been sold to a Chinese manufacturer and they hopefully have a different approach to these iconic cars...I am continuing to work on the splicing of individual cells within the stacks and cannot report as to which method it the best yet...Cheers for now
While I applaud your tenacity. I don't think the average consumer of these cars wants to tear apart and experiment or attempt to fix the high-voltage system themselves, as you do.
Be careful and good luck.
 

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I'm hoping my efforts will lead to some solutions for what should have been a very repairable situation and save over 10,000 ED3 (not sure of the exact production numbers) from an untimely demise...The electric vehicle movement is about sustainability not unbelievable waste....Hoping that someone will start up a refurbish business for these battery packs, although the market is probably too small for much commercial success...time will tell
 

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@Jmk2020 Do you have a part # for this replacement battery please?

While I have no problem with basic algebra and measuring resistance, then using

V=IR

to calculate a voltage to slowly revive a battery, I'd rather not risk myself getting shocked accidentally, especially up in that canyon where it might take a while for EMS to reach me to save me.

That crash sensor error has me worried about the pyrofuse, which is another possible concern where to source one.

But as @Jo e Lefors it might be best if I let this rest, at least for a while. Maybe come up with another plan of attack first....

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