[Hobiecat]

Woke up to a smell of rotten eggs in the house, checked drains in bathroom and laundry rooms thinking sewage backup, wife informed me that the smell was outside to my relief. Then I went out side to check the charge state of the car only to find an intense sulphur smell in the garage and a loud hissing sound coming from the car. State of charge had dropped from 50% the night before to 30% in the morning. Decided to move he car out of the garage in case of fire and it functioned fine but called Mercedes Roadside assistance and she is on the way to the dealership.
After a while of being unplugged the hissing subsided a bit, removed the hood and it seemed to be coming from the 12v battery. Waiting until MB service opens at 9 to ask them but I suspect since they discontinued sales of smarts two years ago they likely won’t have a clue.
This happen to anyone else? In 800km this has shaken the faith a bit.

 

[Jeb Baker]

Good that you are still under warranty. Should be a free repair. I know the 12v batt gets recharged when you plug in, saw this on a meter. The reading was over 14 volts. If there was a bad cell in it, and no resistance, then possibly the amps went way up, cooking the battery and boiling away the sulfuric acid, hence the rotten egg odor and hissing. The discharge rate might be the of exceeded the plugin rate, especially if you were on 110v at the wall. So the main bank discharged too, trying to get the 12 battery up. Hopefully MB just needs to put in a good 12v battery, and no wires were fried.

 

[Hobiecat]

Thanks for the note. Problem is that the main battery did not charge at all while plugged in. Interesting to figure out if the charger charges the main batt which then charges the 12 v battery, that would explain the main battery discharge if the process is activated by plugging in he charger. Are there any links to learn how the systems work in these cars? The more I can learn about how this works the better chance I have to deal successfully with the dealer. Mercedes said they have to wait till next week cause their electric tech only works one day a week. They did say that they charge $280 to diagnose the problem which will be refunded if it’s a warranty issue. They also said it could be rodents chewing on the wires which is not covered. That would have happened at the dealership where it sat for 2 years before I bought it I could be in for a fight. Let’s hope it’s just a bad battery and that it did not damage anything else in the electrical system.

 

[Hobiecat]

MB just got back to me, they were surprised I had not brought the car in for a safety recall, seems there is a safety issue with the charging system...go figure, Dealer told me that they check for recalls before they release the car off the lot. Doubtful. So a major refit of the charging system is underway. Best to check your VIN to avoid a catastrophic failure, especially if you put your car in your garage.

 

[Jeb Baker]

If your 2018 sat for two years on the dealership's lot (and this is the same dealership where you are sending it for service and where they check for recalls before releasing?), the onus should all be on them. My 2017 was purchased July 2019 from a dealership in New Jersey, with only 226 miles on it. But it's history showed it had been up in Maine originally, and both it's 12v and it's high-voltage traction battery were replaced with new ones. I figured someone left it uncharged for more than 14 days somewhere.

I'm wondering though, maybe the high-voltage battery would have charged just fine if it wasn't for the demand to charge up the 12v battery. I.e, the onboard charger's current to the main battery was less than the main battery's current going to the 12v. battery, so by morning the main battery showed a depletion.

The 12v battery with the car off, not charging up, and undisturbed (no doors have been opened and all gauges undisplayed) measures 12.76 volts. Once any door is opened, the voltage drops to 12.43v, the display, interior light and guages light up, and a fan goes on for a while in the front of the car. If nothing else is done, the car returns to dormant, the voltage returns to about the same voltage.

If the key is inserted and turned to position 1, the 12v battery reads 13.6v, which the main battery is supplying voltage to charge the 12v battery.
Turning the key to position 2 does the same, "starting" the car does the same. Plugging the charge cable in does the same as well, using either the 240v (@30amps) cable or the 110v (@9 or 12amps) cable.

I have no idea what amperage the "alternator" (for lack of a better term, since it is no longer a belt driven motor, but a circuit board 12v charger of some type) can deliver to the 12volt battery, but apparently it is quite high, if it was limited to 13.7 volts and boiling away the battery. Maybe that is something the recall fixes to prevent this from happening.

I did find this link for a list of TSB's (Technical service bulletins) 2018 smart fortwo Electrical System Technical Service Bulletins
You may find this helpful, I haven't fully explored it. Not sure if it applies to all countries, just NA, or just the US.

 

[Hobiecat]

Believe the versions are the same for NA with exception of units of measure. I’m in a strange place since there was nothing I could not fix on a gas engine, now when I look under the hood I recognize almost nothing. I have other experience with smaller lithium batteries and am aware they can”brick” if over discharged becoming unusable. Think this applies to the main battery from what I have heard. No the dealership I bought it from was in Ottawa, had it shipped to Toronto, had never seen it or even driven one before it was delivered. That dealership pulled some other tricks, they would take the sd cards out of the new cars and then sell them to the new owners for $400 CDN. And other stuff, not dealing with them, getting fixed here in Toronto. The impression I got from the dealer is that this recall is a big deal. Major components to replace, calibrate and test. I’ll check out the link you sent thanks.
Just happy at this point it was not mice. That would have been a whole new fight.

 

[Hobiecat]

In case anyone is interested, the car has been at MB for 5 days now, service manager refuses to tell me what went wrong, what the damage to the car is and if it is covered under warranty. Keeps defaulting to the need to hear back from Germany. No further mention of the safety recall issue. Has asked some leading questions like “did you use an extension cord to charge? Was there an electrical storm that night? Did the power go out that night?
If I were to guess, I’d say they are looking for any excuse to deny the warranty claim Very much a don’t call us, we’ll call you approach. Did say there was much more damage then just the 12v battery yesterday, today hinted at it just being the battery. A bit frustrating since this is my only car and I’m stuck at home.
Have to say I’m not impressed with MB thus far.

 

[MB DNA]

In case anyone is interested, the car has been at MB for 5 days now, service manager refuses to tell me what went wrong, what the damage to the car is and if it is covered under warranty.

Keeps defaulting to the need to hear back from Germany. A bit frustrating since this is my only car and I’m stuck at home.

Have to say I’m not impressed with MB thus far.

Count me as “interested”...

If their EV Tech only works one day a week and they are involving the “talent” in Germany this could take a while!

When our MY15 ED had issues and required input from Daimler no updates were freely given and details were very sparse.

Several weeks and a few thousand in warranty parts later and all was well - have had no problem since.

Note, if this is the selling dealer AND your smart is under warranty THEY OWE YOU A COURTESY CAR!!

Ask nicely but if refused, don’t be a nice guy. Call the M-B 800 number and demand a loaner!

 

[Hobiecat]

Thanks for the note. Sadly or not, I could not take dealing with the selling dealership any longer, this is a local dealer dealing with the repair. I’ll just have to wait it out. Will see what they say in the next couple of days and think about a loaner car then. I am starting to think that they may feel repairing this car may present too great a liability for them. My house could have burned down if the car remained plugged in much longer. Then they just refund the purchase price or provide a replacement which would be difficult in NA since I doubt there is any available inventory of new units. I really did like the car for the three weeks I had it.

 

[MB DNA]

Hobiecat, even though there is the underlying dealership disconnect THE WARRANTY is w/M-B.

As the loaner cost would be charged against the warranty it does provide a little incentive for them to seek a prompt and proper resolution.

I’d at least ask especially in view of that being your only car?

 

[Hobiecat]

So they changed the 12 v battery and checked out the car under warranty, the report indicates it threw a bunch of error codes in the 12 v system which they cleared then charged and the codes did not reappear so the car was given a clean bill of health. Time will tell. Cause undetermined but suspected failure to perform the safety recall last year may have had something to do with it, my guess is the car was left uncharged for an expended period before I bought it which killed the 12 v batt. With luck no other damage was done.
Thanks for your feedback.

 

[Jeb Baker]

With luck no other damage was done.
Thanks for your feedback.

Please keep us posted. Do your cables to the battery seem new or different now? Could you scan & post the paperwork on the work that was done? Is your battery any different (make/amp hrs, etc)? I'd love to compare to what I have.

 

[Jeb Baker]

Also note this is an enhanced flooded battery!

 

[MB DNA]

Also note this is an enhanced flooded battery!

Interesting primer on EFB batteries (generally used in stop/start applications) - who knew???

⊳ AGM and EFB - What is the difference? ❘ Banner Info Centre

What are the differences between an AGM and EFB battery? We’ll show you ≫ different battery times ≫ areas of application ≫ tips for changing the battery. Find out more now!

www.bannerbatterien.com

 

[Jeb Baker]

Aaaand now, it looks like I don't have the right battery in the car! According to all the mb parts online stores like this, my battery, which ends in 02-00, is for the gas engines, the one that ends in 08 (453-982-00-08) is what I'm supposed to have!

Can anybody look and see what you have in your 453? (gas or electric)

Now I'm concerned!

 

[khlam]

Glad to look under the hood for you.

From my 2016 Prime DCT (453, gas, without start/stop option), look like it still has the original battery:

12V - L2 VRLA 60Ah 680A (EN)
VRLA (AGM) special technology
VARTA
DC A 453 982 0208
24410 2324R

 

[24trams]

FWIW: My 2019 EQ coupe 12V battery has a sticker that is identical to the photo posted by Jeb Baker.

 

[Jeb Baker]

So just to re-iterate, I and 24trams batteries both foe 453 EV/EQ's are:

12V - L2 EFB 60aH 510A
Enhanced Flooded Battery special technology
DC A 453 982 0200
2440 5613R

Neither our's or Khlam's gas 453 smart are using the 453 982 0008 part as listed by various MB parts sites.

Again, I ask anybody else with a 453 please post your 12v battery model and specs.

A reference posting will be a great help for in the future when we need to find the proper battery and MB stops carrying them for us.

 

[Hobiecat]

Was hoping to wait for them to check the codes but I’m told it could take a few hours and if they find any problems then parts will have to be ordered, guess they are not quite as confident as they seemed when they handed back the keys. Will go back in week after next. Will advise when there are any updates. I love how we are focused on sourcing parts for when MB abandons smart owners. Reminds me of my Fiat days.