Speak EV - Electric Car Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
Over 7 weeks ago our B250e shuddered to a halt in Milton Keynes, with an alarming message "Stop Switch engine off". Green flag recovered us home, and then came the following morning to take the car to MB in Oxford.

After nearly two weeks of it being with them we received a call to say that the battery has had an internal failure and needs to be replaced. However we were then told that the battery is on back-order and they have no indication when stock will become available. Fortunately, since the battery is covered by MB then we'll have nothing to pay, but how long is reasonable to wait for the car to be repaired?

We're fortunate to not needing to rely on the B250e as my wife can take my car to work and I'm working from home, but sooner or later we will need the car back.

Are there any consumer rights that would support us in rejecting the car after a certain period of time, either with a trade of an equivalent vehicle, or a cash payment? Or are we stuck and have to wait for a replacement, which could take months as I'd doubt MB (or Tesla) would restart production for a single battery, meaning we'd have to wait for a few more batteries to die before any new ones would be made.

And, as a side issue, do you thing a replacement would be built using the latest Tesla cells? There may be a useful increase in range if that were the case...
 

·
Registered
Joined
·
4,336 Posts
You can reject a car up to 6 months after purchase with this type of fault relatively easily, but after then it is much more difficult.

The Car Expert's guide to what to do if your car is faulty or not fit for purpose

I'd also check out the terms of the battery guarantee - if it is like Nissan or Renault it is not "new for old" but "old for old" up to a certain minimum capacity. In other words in the event of a complete failure you might get a worse battery than the original was prior to failure.

I can't believe that you'll get the new cell technology.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #3
Thanks for the reply.

We bought the car just under 2 years ago from Mercedes as a used car. I'd be surprised it we don't get a new one, since it's on back-order, which to me says that they're waiting for a new batch to be produced. And it's that assumption that makes me think that Tesla wouldn't have kept in stock what are effectively at least 5 year old cells, and since the cell size is an industry standard then they would make any new battery packs from the latest cell technology.

I'll prod MB for an update on whether the battery is still on back-order, as they're hopeless at providing information unless they're asked.
 

·
Registered
Joined
·
4,336 Posts
'Fraid I think that Hairy Leafer is correct. Nissan and Renault have centers where they repair batteries by replacing individual cells and potentially other components that have failed then send these to dealers install in warranty claim cars (although they sometimes send the cars to the specialist center). I'd suspect that MBUK are just waiting for somewhere to repair a batch of batteries. I would be amazed if MB aren't required to recycle more batteries from accident damaged cars than they need for warranty claims.
 

·
Registered
Joined
·
603 Posts
And, as a side issue, do you thing a replacement would be built using the latest Tesla cells? There may be a useful increase in range if that were the case...
Not a chance, especially not the newest 4680's, they are not in full production yet. They wouldn't fit for a start. As the current 2170 cells only came into production in Tesla in 2017/18, my bet is your battery pack was built using 18650 cells used in the Tesla Roadster. These are still available and used in power tools and laptops, so pretty confident it would be rebuilt using those.

Good luck.
 

·
Registered
Joined
·
603 Posts
or they busy are phoning round all the scrappers..
Yep sadly i agree with Hairy Leafer too, you are almost certain to have a recovered pack from a written off B250E fitted. If MB dont have some "sitting on the shelf" packs as spares, then not a chance MB will persuade Tesla to build them a new one.

They might relent and pay a specialist company to rebuild your pack with new 18650 cells that for the ones that have failed. Again i wouldnt expect 100% all new cells, they will most likely just replace the ones that have failed.

There could be a strong chance MB will just write the car off and give you a cheque for it's current 2nd hand value, or offer to supply you a 2nd hand like for like exchange.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #10
Thanks for the info chaps. MB have finally given us an expected battery delivery of around the 10th November. I'll ask whether it's a new one, or a recycled/refurbished/repaired one and report back.
 

·
Registered
Joined
·
2,205 Posts
Most of the spares for the B250e powertrain seem to be ordered directly from Tesla, the Back Order system just means Merc dont have it within the local spares network and need to order it.

While its fun to speculate that "Tesla wont build Merc a new one", i would be astounded if a large established automaker like Mercedes didnt have an agreement in place to ensure spares availability to see out the warranty period and X years beyond.
 

·
Registered
Joined
·
162 Posts
Sadly for EV owners, this is the 'elephant in the room'. Most of us fans talk about replacement battery packs, individual bad cell replacement, but most of that is wishful thinking. How many 24kwh Leafs or imievs have had their battery packs replaced? It's not economically viable. When a car struggles to go 50 miles on a charge, it's as good as worthless.
As for the OP's situation, I hope it gets resolved ASAP. OP: keep us posted. It'll be interesting to find out if Mercedes write the car off, give you an old pack or a shiny new one.
 

·
Registered
Joined
·
3,328 Posts
A lot of cars seem designed to make the battery easy to service and replace nowadays.
 
1 - 13 of 13 Posts
Top