12V battery charging problems - no-start

[bcolchagoff]

I am in the market for a 2015-2015 used B-Class electric. I have driven one and really liked it. However, on the CarFax it said that the car was a "buy-back" (Vehicle reacquired by Mercedes because of an issue). On the CarFax report, I saw numerous service entries with descriptions like:
- "Battery/charging system checked"
- "Battery charged" or "replaced"
- "Electrical system checked"
and then finally: "vehicle reacquired... reason: Battery drainage / No start".

So, I passed. I don't want to inherit a lemon.

Months have passed, and I found ANOTHER B-class buy-back with almost the same descriptions! The seller has been honest, providing a carfax report and the California Warranty buyback notice.

The seller also states:
"This vehicle was a manufacturer buyback for a no-start complaint. Mercedes inspected the vehicle and replaced an engine harness and power distribution block prior to reselling the vehicle to us. It's fully guaranteed by Mercedes and comes with warranty through 9/18/18 or 50k miles. Mercedes also includes a 1year/12k mile warranty on the buyback complaint."

I googled and search this forum and didn't see anything. so, questions:
- Is this a known problem?
- Does it only happen if you leave the car for significant periods of time? or any time?
- Is there a fix for this (note, from descriptions, it seems to be with the 12V battery, NOT the drive system battery)
- There's still the manufacturers warranty in place. Did Mercedes really fix it?

It think it's very odd to see the exact same problem listed on 2 buy-backs with so few B-Class used cars out there.

Advice?

 

[JeffRay]

BC,

I would not acquire a new MB with this kind of history. It is not a problem as you said this forum members have reported. It is a standard B class car built on a Tesla battery pack and motor so keeping a 12V battery charged should not be an issue but it was in these two cars. While I carry around jumper cables, who needs the hassle.

The good news for you is that a bunch of 2014s will be rolling off lease this year, like mine. With the advent of longer range and less expensive electrics, the asking price for our used 2014s should drop. MBFS is expected to lose money on our returned cars.

It is a great car. Having surveyed the other available electrics, I am planning on extending my lease to bridge to the next luxury, preferably MB electric offering.

 

[bcolchagoff]

Jeff,

Thanks for the advice. Yeah - I came to the same conclusion... why temp fate? I just purchased a loaded B-Class with all options (premium, range, parking, etc) from a MB dealer. It was 10% more, but with piece of mind.

Also, it's for my wife, so I want her to have the best experience and fall in love with electric cars.

Buff
2014 BMW i3
(and now) 2014 Mercedes B-Class electric

 

[JeffRay]

Buff, so you came clean as an original i3 owner. Most of us considered it but in my case, I needed room in the back for two pre-teenagers so the BMW did not work for me. My sister ended up getting one and she loved it to get to work and scoot around LA.

Trust you wife will enjoy the ride, the creature comforts and not having to go to the gas station.

 

[wtzouris]

Hey Jeff, surprise, my lease is up in December 2017, and Mercedes said no to any sort of lease extension. Not unless I had another car on order . They want the car back. I don't want to do the buy out (They want $23k) so I will be leasing a 2017 i3 REX with 94Ah battery. My only concern is the smallish cargo room, but I know it drives well. I'm looking forward to it. Mercedes Benz could have kept me in another B-Class if they had done any updates, like a 44 kWh battery and DCFC, that would have been enough for me to lease another one. Anyway, my winter tires/wheels are for sale! Good luck to you and let me know if there is any secret to extending the lease beyond the 3-year agreement.

 

[bcolchagoff]

Look, they are both good vehicles... and isn't that what we want for the EV community? Real choices with the least compromises?

Back in spring, I debated hard between the B-Class and i3. The i3 styling seems to be a "love it or hate it" affair. I like it. The Merc i think just about anyone would like -- class act.

Ultimately, for my driving, the lack of a DC Fast Charger, and the fact that MB won't offer B-Class as CPO tipped the scales. I picked up a CPO i3 with 4 year - 85,000 mi CPO warranty and Fast Charging for 10% less then a similar used Merc with remaining orig factory warranty.

For my wife - she loves the Merc style, and commutes 25 miles each way to work -- so no range issues. A perfect match. (I will probably "steal" her Merc now and again just for a change of pace and when hauling 5 people).

I don't wanna get flamed, but would like to make two points from experience:
- Myself and my 3 sons (all over 6'1" and 220 lbs) jump in the i3 for around the town stuff. It's no R350, but it fair enough for town stuff, and
- I take the i3 to weekly grocery store run, and fit food for aforementioned giants in just the hatch area without using the back seat.
That being said: I would clearly prefer the rear seat and hatch room of the Merc over the BMW.

Ah - to have such choices in EVs at reasonable prices is really great for the whole community. I can't wait to see the new breed of Merc EVs -- it's only gonna get better.

Buff
2014 BMW i3
(and now) 2014 Mercedes B-Class electric
2008 Mercedes R-350 (family truckster)

 

[JeffRay]

WTZ, my strategy is more complex than it needs to be:

1. Wait and see how things transpire as MB understands they have a money loser on returns.

2. Try to extend the lease without a car on order. Get past the business as usual person.

3. See if I can get a new one on friends and family deal time.

4. See if MB decides to unload remaining inventory to clear the decks.

5. Look at used ones, like mine, which will hit the market and sell for less than $18K.

6. Go without EV and just wait.

7. Look at Ford Focus since they are offering a big incentive.

8. Keep eye out for Audi EV. Stylish and longer legged.

Would be a lot simpler if option 1 works out, sigh.

 

[JeffRay]

Buff,

No flaming here, sir. Well, your kids must be trim and fit. I got into the rear seat and was uncomfortable. That being said, I would not describe myself as trim and fit, just a tad overweight! My two daughters took one look and said NO! They love the MB250e.

I absolutely agree that this is a high class problem we have here, sorting between quality builds as the offerings get better and better. I don't really need a long range car either as I have our family wagon for that. So would be quite happy with a 100+ range electric. Out east where the winters are not so bad, the range does drop for me to around 40 miles. As I live in a condo without a garage and park the car on the street to boot, recharging twice a week was required. A stop during week at dealer to recharge (and chill) was the drill and in a commercial lot on weekend overnight.

 

[GlennD]

While I loved my B I also love my eGolf. With my range needs any EV will work for me. I looked at the BMW's and the Bolt. They do not work for me. The Bolt is cheaply made and it just seems to be about range. After I totaled my B I thought about another one but I would have had to take money from my 6 month reserve and I did not have to for the eGolf. I lost my down but the gap insurance covered the difference between what I owed and the payoff.

 

[bcolchagoff]

Ok. One more question to get your input...

The Mercedes B-Class I'm purchasing is remote: I'm in Maryland and the dealership is in CA. I've bought other cars remote before (including my i3 from Connecticut), but I think there's a general lack of knowledge about the car at the dealership.

Car looks super clean, carfax clean, all that checks out. It's a 2014 with 17K miles, and 14 months left on original warranty. What concerns me is the Battery Certification and warranty. I can't tell from the CarFax report if the battery is certified. It did have yearly service, but there's no mention of battery work in carfax.
Carfax report: http://bit.ly/2vs2gFB

The sales guy is a little young, and he seems to say "I understand" and then goes away and gives me not quite what I asked for. It's been 3 days of back and forth on this sale. The final thing is:I'm trying to get to "is the battery status certified"? I don't feel confident.

The last iteration of this, I told him I had to have a document signed from the dealership that the battery is still under warranty, or at least they need to provide a report of battery status showing no substantial degradation After so much back and forth, I was willing to compromise the on the battery warranty if I only knew it was in good shape. I've researched a lot, and all the reports point to the fact that if the battery wasn't abused, I shouldn't have significant degradation over time.

So, here's what he gave me, and I'm supposed to sign the papers remotely tomorrow:
- A text from the sales guy stating "Yes sir the battery is perfect ... and everything on the car is under full warranty",
- and then the following image (via text):

, or as a PDF https://www.dropbox.com/s/vdj05u73a9p0pgm/Merc B-class battery report.pdf?dl=0

The battery looks ok, but they didn't really do a proper test right? And they didn't tell me the battery capacity left in KWh.

So, my questions are:
- Am I making too big a deal about this?
- Is battery abuse so unlikely that the juice is not worth the squeeze?
- Or should I make the dealership due a full certification test and provide the full results?

I'd love to here the community's opinion on this.

Thanks,
Buff
2014 BMW i3
(almost own) 2014 Mercedes B-Class electric
2008 Mercedes R-350 (family truckster)

 

[JeffRay]

1. If you are buying the car from a California dealer, they have to disclose any defects by law, as you pointed out with the 12v battery.

2. Since this is a 2014, there is a record of the recall software upgrade having been done on the car last year, ask for it. Dealer can get.

3. I don't know how to read the image you posted, maybe another member knows.

4. I had a battery test as did others. I was told it was fine but never got any paperwork.

I think you are good to go. BTW, as I am going to attempt to negotiate the buyout price of my 2014 with 10K miles, were you able to get a price below $20K or was it more like $23K.

Your young salesperson is in a California dealer, right? They are really the only dealers that have a bunch of the electrics. Your Maryland dealer like most east coast dealers likely doesn't know jack.

 

[bcolchagoff]

Thanks Jeff,

Yes. This is a Mercedes dealer on the outskirts of LA.

So, I tried hard to get them to come down, but could only get them a little south of $23K. I did get them to throw out all the BS "documentaion fees" and "notary fees" (they were gonna charge me $250 for a notary!)

The problem I had was this is a very clean, and very loaded B-Class (premium, range, parking, interior). I don't think you could get another option. My wife had very specific color, mileages, options she wanted.

There were others in the area with less stuff, but they are advertised at $21.7K-$22.8K.

However, a used one with 18K miles in CO was asking $19.5K -- she said she had been quoted a $19K trade-in. A used one in Ohio showed up for $19.8K (not the B-class market?).

Edmunds says trade-in $18K, personal sale $19K. They may be low.

Good luck.

 

[wtzouris]

I think you don't need to overthink the battery certification. These cars should be good for 80-100k miles without anything but fluid changes. That includes brakes. The 12v battery should be changed every 3 years. It is essential for the car /computer to work. Put in something good like a Bosch or Exide advanced AGM with a handle on top. An extended warranty covering the drive unit (motor) and gateway would be ideal. The battery is not going to be the problem. it's going to be a computer board failure . Or a motor failure. I have 30k trouble free miles on my B-Class and am turning it in in 4 months. I don't know how I feel about used B-Class in the $20k price range. I'm told the wholesale (auction) value is $14k for my 3-year old car, which stickered for $51,000/ my buyout is $23k and I say no way -- need DCFC and a larger battery. My next move is an i3 with 94Ah battery and REX. The REX is so my wife can drive 200+ miles in a day. I will choose DCFC as my way of making longer trips. I like the compromise. The only thing I will miss is the B-Class cargo capacity. Everyone says the i3 is immensely fun to drive I had one for 3 days and it was addictive. Makes you not think about how it looks. Although I am looking forward to being noticed after 3 years of not being noticed. The B-Class ED is a great car, I will miss her.

 

[MikeP]

Hello, I've come very late to this forum and topic, having just purchased my B Class EV. Here's the scenario:
1. When the car is left plugged-in overnight to the Mercedes garage 3-phase charger, using the cable that came with the car, the car was fully-functional afterwards. The car sent a message stating Charging Terminated early evening, leaving the car fully-charge for the rest of the night and morning.
2. When the car has been left plugged into my 13-amp Mode 2 charger, using the cable that came with the car, continuously for 3-days, the car was fully-functional afterwards.
3. When the car has been left plugged into my 7kW Chargemaster HomeCharger and left plugged-in overnight. In the morning the 12-volt battery was completely depleted. Note that the HomeCharger has a tethered cable, so the cable that came with the car is not being used.
4. The depletion of the 12-volt battery was being caused by a contactor in the engine bay fuse box cycling on and off continuously until the battery drained to zero.

Has anyone else had this experience? The problem appears to be an incompatibility between the car and the 7kW Chargemaster HomeCharger, the car being unable to establish if the HV battery is fully charged and keeps poking an enquiry causing the charging contactor to cycle.

 

[JeffRay]

MIkeP,

First, welcome and enjoy the ride.

Second, whaaatt? Over my non-engineer level. Maybe GlennD can chime in here. He knows stuff. How in the world did you figure this out? Never had this problem in 4+ years but only use commercial chargers or the pokey 110v MB supplied cable when car is parked at work for a couple of days like it will be next week.

 

[MikeP]

Thanks JeffRay,
I love the car but this total deletion of the 12-volt battery is a complete mystery to MB (here in the UK) and to ChargeMaster - hence my post. I have done extensive testing with a multitude of charging permutations over many weeks. My local MB dealers say they have never seen this before (and have enlisted the help of MB Europe) and ChargeMaster so far say it's the car. Meanwhile I'm stuck in the middle!
If it helps anyone I can upload my test regime and results, including a video of the contactor cycling (assuming it is possible to upload on this forum!). All thoughts gratefully received!

 

[JeffRay]

Mike P.,

To get a quicker response from members, you might try to PM someone like GlennD or Tony Williams or other UK members. It will hit their email and they can see your question straight away.

I am assuming MB will be replacing the 12v battery for you under warranty as this would not be considered normal wear and tear.

 

[MikeP]

Will do, thanks Jeff

 

[GlennD]

Quick Charge Power has a fast L3 charger for the B. It is 3K but that u-is in line with Tesla charges.

 

[GlennD]

The unit is Chadmo. I wish it was CCS since that is where the US seems to be headed, Right now there are fewer CCS chargers but that will change.