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2013 Smart Car ED

Parked for some months in storage with the charger connected. Someone turned off the breaker to the garage and the car sat for 4 months with no power to the charger.

I checked on the car and the display said "HV Battery at reserve charge now", the following day I came to sort the issue with the breaker and found the headlights flashing and the P for Park illuminated. I put the key in and turned it to the on position and the P light went out. Checking the 12v battery in the passenger floor I found it dead and recharged it.

I reinstalled the 12v battery and out the key in. The display says "HV System" with an arrow and the word "Workshop". I plugged in the charge cable but it will not begin charging the HV battery.

I called the dealer and they say that if the 12v battery goes flat it creates an open circuit in the HV battery pack and you have to replace the whole HV battery pack...

Seriously... So if the battery runs flat, the car is totaled? Please tell me this is not the case.
 

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Parked for some months in storage with the charger connected. Someone turned off the breaker to the garage and the car sat for 4 months with no power to the charger.

I called the dealer and they say that if the 12v battery goes flat it creates an open circuit in the HV battery pack and you have to replace the whole HV battery pack...

Seriously... So if the battery runs flat, the car is totaled? Please tell me this is not the case.
Sadly that seems to be the case - dunno that anyone with a flat-lined HV battery pack has been able to breathe life back into it???

In retrospect, if the breaker to the garage hadn't been turned off, having your 12V on a trickle charger might have saved you from this potential disaster???
 

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Sadly that seems to be the case - dunno that anyone with a flat-lined HV battery pack has been able to breathe life back into it???

In retrospect, if the breaker to the garage hadn't been turned off, having your 12V on a trickle charger might have saved you from this potential disaster???


If Mercedes has produced a car which is totaled if it is left parked, and it gets out in the Media, no one will ever buy one of their cars.

I can see the articles now "Mercedes - Leave your headlights on and total your car"
 

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2013 Smart Car ED

Parked for some months in storage with the charger connected. Someone turned off the breaker to the garage and the car sat for 4 months with no power to the charger.

I checked on the car and the display said "HV Battery at reserve charge now", the following day I came to sort the issue with the breaker and found the headlights flashing and the P for Park illuminated. I put the key in and turned it to the on position and the P light went out. Checking the 12v battery in the passenger floor I found it dead and recharged it.

I reinstalled the 12v battery and out the key in. The display says "HV System" with an arrow and the word "Workshop". I plugged in the charge cable but it will not begin charging the HV battery.

I called the dealer and they say that if the 12v battery goes flat it creates an open circuit in the HV battery pack and you have to replace the whole HV battery pack...

Seriously... So if the battery runs flat, the car is totaled? Please tell me this is not the case.
Regarding the red text: no, the death of the 12V battery does not kill the HV [traction] pack. Many Smart EDs have had their 12V battery fail by now and you'd have for sure heard about it if the red text were true.

What does seem to be true is that if the HV pack is completely drained that the car needs to be seen at a dealer (and no one on the forum has reported back with what the outcome was to my knowledge [and I've looked]).

The green text sections also seem a little contradictory. If the headlights were flashing, the 12V battery had to have some amount of charge.
 

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If Mercedes has produced a car which is totaled if it is left parked, and it gets out in the Media, no one will ever buy one of their cars.

I can see the articles now "Mercedes - Leave your headlights on and total your car"
Perhaps BUT the Owners Manual does carry a caution regarding the charging requirements.

You are not the first ED owner to have been bitten and yet the lights continue to glow brightly at BOTH of the local M-B dealers??

Curious, was the HV at full charge before you left and was there any impact from cold weather?
 

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Not contradictory at all. The headlights were dim and flashing every 30 seconds of so and the P indicator on the shifter was on. When I put the key in and turned it to the KO position the dash flickered and then went dark. I imagine that there was so little juice in the battery that the computer started to freak out, hence the lights trying to come on and the P indicator being illuminated. When the key is put in KO, the car energizes the stereo, the solenoids for the HV contactors, etc and that was clearly enough to flatten the battery. By dead I mean that it had 3.2v.

So if the HV traction pack self discharges from fully charged to fully discharged in 4 months that seems odd, but OK. So if this is the case why is there not a warning right in the instrument cluster stating that if the vehicle is stored for more then say 60 days, that it must be plugged into a charger? I mean if you have a fairly common condition that will total the vehicle, one would think they would be pretty adamant about warning the user...

In my life as a professional mechanic, I see vehicles stored for months at a time frequently and not having some pretty obvious warning of such a condition is grossly negligent.
 

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Some comments:

I have accidentally flattened my 12V battery (left parking/marker lights on) and it caused no problems. I recharged it and thre wer no problems.

The dealer's remark about a dead 12V battery creating an "open circuit in the HV battery" (whatever that could mean) is simply wrong. When the key switch is off and/or there is no pilot-pin signal from the charging plug (which would be the case if someone pulled the circuit breaker), the 12V battery is not connected in any way (i.e. via the DC-DC converter) to the HV battery. So any accessories left on only discharges the 12V battery and does nothing to the traction battery.

I really don't see how a fully-charged traction battery can self-discharge much over 4 months. Lithium batteries don't behave that way. What kind of temperature was the car subjected to? unless ther were persistent periods below -25C, than storage temperature issues can be excluded.

But, there is one thing about your problem that bothers me - I have been watching with a bit of dismay as software "engineers" have increasingly displaced "real" mechanical engineers out of the automotive design process. I'll never forget the software engineer who founded a now-defunct startup that built my electric motorscooter - where he programmed the scooter to stop dead (even if in the middle of a left turn on a highway with a truck bearing down) if a sensor detected an abnormal temperature or cell under-voltage condition - without considering that preserving a human life is far more important than the chance of damaging a $90 lithium cell or a $2200 battery pack (which would be destroyed along with the rider upon impact anyway). They revised the firmware to remove most, but not all of these scary conditions. Then they went out of business.

And before I bought my Smart Ed, I almost bought the similarly-styled Think City EV until I found out that a design bug caused a non-replaceable PC board in the battery pack to go up in smoke if it was turned on while the heater control was in the "on" position more than 2 or 3 times.

So, the Smart ED may very well have a stupid software bug that ruins the traction pack if some combination of conditions occur.

Note that we have a ongoing case similar to yours from a Canadian (but not a particularly cold part - they saw -25C for only a day here and there):

https://www.smartcarofamerica.com/forums/f170/drive-system-engine-off-153530/
 

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Let me begin by saying that I have been a german car mechanic for 35 years.
This dealership seems to know nothing about the Smart ED, they kept using the phrase "Discharging creates an open contact in the traction battery which can not be repaired" and told me that even if I had the Battery Assurance Program, that Mercedes goes over it and if you missed any service by even a day or did not do everything perfectly they would deny the claim and that a replacement costs nearly $20k if they can even get them anymore. "

I did manage to scan the car with an Autel Scanner which can emulate some of the ability of the SDS. I attached screen grabs, but it appears that the BMS shut off the HV battery to protect it, the other codes seem to have cascaded from the shut off or could be the result of having the battery supplying the computer go low and give it epilepsy. Nearly ever Mercedes that comes into my shop for a new battery or after having been jumped is full of codes, the computers hate low voltage and start ranting codes like a street preacher. We clear them and test drive to see what returns.

I drove the car last in late December, we never had temps below 28F and not for long. I drove it to wash it, it had been parked for several months and had dropped to 20% so i charged it and parked it again and plugged it in. I guess I should have checked in on it more often. But honestly I never imagined that they would design a battery to consume itself, I mean it is a "Smart" car isn't it...

The R170 and R171 chassis will freak out of the tilt sensor battery (soldered to the alarm horn" goes low, it will wait until the car has been parked for about 20 minutes then begin to flash the headlights 10 minutes flashing 10 minutes off, until the battery goes flat... I suppose something similar happened here...
 

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By "discharging", they mean the traction battery, correct? Most lithium batteries - from cell phones on up, have a over-discharge protection circuit which permanently disables the battery pack if it is over discharged. The reason for this is that attempting to charge an over discharged cobalt-chemistry-based lithium battery runs a very high risk of the battery explosively igniting.

But I'm still wondering why your car self-discharged so rapidly. The time a Smart car sits in factory storage, in transit on a train and ship, then sitting in distributor's and dealers lots would have bricked every Smart in the US if the self-discharge you experienced was normal.
 

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By "discharging", they mean the traction battery, correct? Most lithium batteries - from cell phones on up, have a over-discharge protection circuit which permanently disables the battery pack if it is over discharged. The reason for this is that attempting to charge an over discharged cobalt-chemistry-based lithium battery runs a very high risk of the battery explosively igniting.

But I'm still wondering why your car self-discharged so rapidly. The time a Smart car sits in factory storage, in transit on a train and ship, then sitting in distributor's and dealers lots would have bricked every Smart in the US if the self-discharge you experienced was normal.
Actually they currently have three cars sitting on their lot. All were purchased at local lease return auctions, all had sat for several months and had flat batteries, all were towed to them for repair and all needed now batteries - none of the people who bought them for $4500 were willing to pay $20k for a new battery...

I also called EV West in LA and they have two Smart ED cars on their lot, both have bricked batteries....
 

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This dealership seems to know nothing about the Smart ED, they kept using the phrase "Discharging creates an open contact in the traction battery which can not be repaired" and told me that even if I had the Battery Assurance Program, that Mercedes goes over it and if you missed any service by even a day or did not do everything perfectly they would deny the claim and that a replacement costs nearly $20k if they can even get them anymore. "
Was this (Seattle area?) "dealership" originally a smart Center, do they still service smarts/EQ's, do they have factory trained M-B EV mechanics?

Very odd that "...they currently have three cars sitting on their lot. All were purchased at local lease return auctions, all had sat for several months and had flat batteries, all were towed to them for repair and all needed now batteries - none of the people who bought them for $4500 were willing to pay $20k for a new battery..."

Apparently these auction purchases were made by private parties who knowingly bought an off-lease smart (with remaining factory warranty?) paperweight?

While seemingly all car deals come with some risk, odd that MBFS would sell an off-lease smart without some "AS IS WHERE IS" disclaimer especially if it died while in their possession?
 

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Very sad... 2.3 volts resting on a lithium cell means "ruined" and a hazard if any attempt is made to recharge it. The lowest they should ever be allowed to get is 2.8 under a high load.

This is the kind of BS design that I encountered when I first endeavored to get some electric urban personal transportation (motor scooter) from China. The quality was crap and basically felt like they were exploiting people's concern about their environmental impact to swindle and scam them.

I still think this self-discharge is not normal behavior. The only thing that should draw from the traction pack when the car is shut off and not charging is a tiny leakage draw from the BMS.

While my Smart has never sat for more than a week or two. I never noticed any decline in the SOC except when it is being driven. Anyone else?
 

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Was this (Seattle area?) "dealership" originally a smart Center, do they still service smarts/EQ's, do they have factory trained M-B EV mechanics?
Yes the Mercedes Benz dealer in Seattle which is also a smart service center and dealer and has factory trained mechanics working on the Smart ED

Very odd that "...they currently have three cars sitting on their lot. All were purchased at local lease return auctions, all had sat for several months and had flat batteries, all were towed to them for repair and all needed now batteries - none of the people who bought them for $4500 were willing to pay $20k for a new battery..."
Why is that "very odd"? MBNA took all the lease return Mercedes and rather than selling them through Mercedes, auctioned them off to independent dealers. I got mine from such an auction via a friend who is a dealer, it still had factory warranty on it when I bought it and I took it in for service under the warranty once, the warranty has since expired, as factory warranties do, all of them.

I made sure my car had a fully charged battery when I bought it but there were others which were purchased by independant dealers which were then put up for sale and sat on car lots for months at a time. Several were sold with batteries which would intermittently fault, as some of the cars had - do a search on the web for "Smart Car ED battery failure" and you can read all about it. When faced with a Smart that does not run you have no choice but to go to the dealer. I have been a German Car specialist for 35 years and own a shop, there is little or no information available on the repair of these cars. So people towed them to Mercedes in Seattle for service and when faced with the cost of a battery and the lack of availability, left them and are searchign for batteries...

I spent all day yesterday calling all over the US including dealers in 11 states, not one could tell me anything other than that they have repalced batteries under warranty but Mercedes no longer has stock in many cases of the proper batteries for these cars. I called a half dozen independents with EV experience across the country and the most experienced was EV West in LA and they have two sitting in their lot with bad batteries waiting to be scrapped for parts.

I agree that this is "Very odd" and frankly expected better of Mercedes, the fact that people were excited about buying a barely used lease return electric car is not odd in the least, nor is it that they towed them to the only place which will work on them for over 1000 miles...

Apparently these auction purchases were made by private parties who knowingly bought an off-lease smart (with remaining factory warranty?) paperweight?
Not "apparently" but factually. Yes people bought lease return Smart ED cars at auctions, knowing that they were lease return cars, that is what happens to lease return cars, they are sold at auction to independent dealers who sell them to people.

While seemingly all car deals come with some risk, odd that MBFS would sell an off-lease smart without some "AS IS WHERE IS" disclaimer especially if it died while in their possession?
What? MBF sells lease return cars, I imagine not many dealers want to sell lease return Smart ED's which most dealers can not service, so they are sold to independent dealers... like most other lease return vehicles - why is this odd to you? This is how the lease return business works... Look at independent car dealer listings in any major city and you will find dozens of 3 year old luxury cars for sale, where do you think they come from? I personally know 4 lots that do nothing but high end lease returns. MBF does not warranty auction cars, if the car still has remaining factory warranty then that is all you get. All auctions are "as is where is".

No one said the cars died which in the possession of MBF although it would not surprise me if they lost some as they do not have storage lots equipped for electrics. At the auction I went to 1/3 of the smarts had no chargers. I picked mine because it had belonged to the service manager at a local Mercedes dealer and was fully optioned and came with two chargers and a factory bike rack and had low miles...
 

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Very sad... 2.3 volts resting on a lithium cell means "ruined" and a hazard if any attempt is made to recharge it. The lowest they should ever be allowed to get is 2.8 under a high load.

This is the kind of BS design that I encountered when I first endeavored to get some electric urban personal transportation (motor scooter) from China. The quality was crap and basically felt like they were exploiting people's concern about their environmental impact to swindle and scam them.

I still think this self-discharge is not normal behavior. The only thing that should draw from the traction pack when the car is shut off and not charging is a tiny leakage draw from the BMS.

While my Smart has never sat for more than a week or two. I never noticed any decline in the SOC except when it is being driven. Anyone else?
Several sites I have found refer to 2.3 as the point where over-discharge protection kicks in, meaning that the battery is not dead, just at it's minimum...

"Overdischarge protection--stops discharge when battery voltage falls below 2.3 volts per cell (varies with manufacturer)."
 

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The lower voltage LiFePo4 cells used in my scooters have "fully charged" voltage of 3.7 and a "do not go below" voltage of 2.5. They are intrinsically safe from thermal-runaway-and-fire unlike the other chemistries, but have a lower energy density and are bulkier, so they never caught on with EVs except for some home-built EV's.

TheLiNiMnCoO2 (NMC) cell chemistry used in the Smart ED also have a "do not go below" voltage of 2.5 volts according to this source:

https://batteryuniversity.com/learn/article/types_of_lithium_ion

I have never found a clear answer as to whether the "do not go below" voltages are for under a current draw or open-circuit. But if any of my LiFePO4 cells were discharged to a resting voltage of 2.3 volts, I'd consider the cell ruined, with only half the energy and especially amperage-capacity if recharged.
 

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The lower voltage LiFePo4 cells used in my scooters have "fully charged" voltage of 3.7 and a "do not go below" voltage of 2.5. They are intrinsically safe from thermal-runaway-and-fire unlike the other chemistries, but have a lower energy density and are bulkier, so they never caught on with EVs except for some home-built EV's.

TheLiNiMnCoO2 (NMC) cell chemistry used in the Smart ED also have a "do not go below" voltage of 2.5 volts according to this source:

https://batteryuniversity.com/learn/article/types_of_lithium_ion

I have never found a clear answer as to whether the "do not go below" voltages are for under a current draw or open-circuit. But if any of my LiFePO4 cells were discharged to a resting voltage of 2.3 volts, I'd consider the cell ruined, with only half the energy and especially amperage-capacity if recharged.
Where on that page did you find the do not go below figures?
 

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Where on that page did you find the do not go below figures?
Scroll down to: Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2 or NMC)

and look at the "Discharge (C-rate)" on the table. It says: "1C; 2C possible on some cells; 2.50V cut-off". Presumably, this is the minimum "cut off" voltage while under 1C to 2C (50 to 100 amp in the case of the smart) discharge. 2.5 volts under no current draw would be far too low.

For comparison, a while back, I ran a scan of my battery pack (using the Sokoloff open-source OBD gadget) at 12% SOC, and the cells were 3.53 to 3.55 volts.
 
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