12 Volt Battery Issues

[Benzak]

My 2014 B-Class Electric Drive has been showing the message "Stop Vehicle See Operator's Manual" randomly during my drive the past couple of months. I see it once every couple of weeks now but goes away after the car is restarted. There is no change in the car's performance. After taking it in the MB dealer for diagnostics, they found the low voltage 12V battery to be the issue and suggested I pay $630 and replace it. I decided I should try and replace it myself. Has anyone had to replace this battery and are there any precautions, sequence of disconnect/connect to worry about?

 

[cblankespoor]

Hi Benzak,

I posted the following in another thread earlier this year...

"Same thing ["Stop Vehicle See Operator's Manual" warning message] happened to me twice in 1 week about 6 months ago...I replaced the 12V in my car with an XS Power Battery and haven't had any Malfunction visit workshop display message since.

I would suggest getting a really heavy-duty 12V battery...yes, they are more expensive, but with almost everything peripheral in our Bs running off that battery, it will be money well spent!

Curt

P.S. The XS Power 12V AGM 2900 Max Amp Car Audio Battery D4700 is the one that fits. And don't forget to purchase the terminal hardware, as it doesn't come with the battery.

 

[JeffRay]

Benzak,

Whenever my mechanic has replaced the 12V in my B250e or E500W for that matter, some other electrical doodad gets messed up. So sequence may be important. Not to say the dealer mechanic will be immune but all in all, it should not take more than one hour labor so that is what you save by doing it yourself and you can choose a lower cost batter.

Examples I have experienced were: error message, sun roof in wagon would not work.

Perhaps there is a YouTube video but find one for our B250e. Remember, with ours, keep the Drive Unit and big battery safe.

 

[WantOne]

My time has come with my 2014 B class. On both 12V issue as well as drive motor replacement.

What are the 12V battery people are using? Dealer charges $650 for it of course but offered to installation only if I provide my own parts.

I saw the XS Power D4700 suggestion from @cblankespoor. Any other suggestions? Firestone website pulled up interstate batteries MTX Article #7015379 not sure how well it’s going to fit our b class.

Suggestions? Thanks!

 

[WantOne]

Responding to my post. Went with dealer batter at about $350 + tax as I’m also doing tesla motor replacement. I’m hoping the new motor will last > 5 years so that this is not end of the road for b!

 

[JeffRay]

WantOne,

Yes, wish your B250e a long renewed life with replacement motor. I don't miss it as much because the only driving I do these days is to take the kids to school a couple of times a week and otherwise be the family Uber driver (errands, shopping, etc). Using my wife's ICE wagon and fill up once a month.

Things should be different in 2021 so as per my other post, will look at MB EQA when it comes to the US. No rush but I did send a note just now to my MB salesperson.

 

[WantOne]

EQA Sounds very interesting. Jeff do you know if MB exhausted the $7500 tax credit yet?

I’d not like another first user experiences like my B class but price and options makes it attractive.... we’ll have myEQAelectricdrive.com site lol.

 

[JeffRay]

WantOne,

MB only sold a limited amount of the B250e so they have not used up the $7500 tax credit. I just checked online since you asked. Same is true for hybrids when I was looking for a leftover GLC350e PHEV.

I consider our B250e to be MB's teething training wheels. They are basically doing it again with the EQA and EQC, installing EV tech into an ICE platform. That being said, I would still look at the option of starting with a lease and buying it off lease at the end if I loved it.

BTW, nothing from my MB dealer so suppose EQAs are going to be sold in Europe first like the EQCs.

 

[Remmisk]

Any of you know if the 12v battery can simply be removed and replaced without any software issues? I am trying to avoid my MB shop for 12v AGM my battery upgrade. Thanks!

 

[PatricioEV]

The 12v system is just like any other car. It just gets power from a dc/dc converter rather than an alternator. I've replaced MB batteries with no issues.

 

[altamonte]

I believe you must hook up a battery tender to the posts to keep 12v available to keep alive all the computers in the car. I know that if it goes to zero, you will likely need to have the dealer re-flash everything.