C350e quoted 14k for replacing battery

Page may contain affiliate links. Please see terms for details.


New Member
Aug 12, 2023
2018 c350e Estate
Hi, I have a 2018 c350e estate with 71k miles which I've been quoted €14k from MB dealer to replace the HV battery. I've already shelled out for a new 12v battery and a pair of speed sensors which haven't sorted the issue and the fault relates to insulation in the battery according to the dealer. Has anyone any real world experience of a battery replacement ( the car was supplied in the UK and imported to Ireland at 60k miles ). I have the car more than 12 months - the problem started about 2 weeks ago with a red battery malfunction and towing sign. It's been towed twice since and now sits in the dealer - and apparently MB Germany has no hybrid batteries in stock so now idea how long it will sit for. When I asked if I would get a new 6 year/100,000km warranty on the battery they weren't even sure. Advice appreciated, thanks.
Can you buy the battery? A guy on a USA forum just replaced (himself) the three traction batteries that sit under the rear seat on his Lexus hybrid. He got a heavily discounted price (circa $3500 vs $6000+) from an on-line Lexus/Toyota parts vendor. He had to carry over some parts/wiring from the old batteries to the new but he described that as being as simple as 'paint by numbers'. Lexus dealership quoted him $1600 as a fitment charge.
Well there is a battery for your car on ebay for £900 with postage,might be worth a look if you are faced with a 14 grand bill ,your car up and running is worth about 12 grand sold to the trade,thats not a nice situation to be in hope it works out for you,will they fit a new battery under the 6 year warranty?
There’s sure to be a growing industry for the aftermarket here, repairing battery packs.

At the end of the day this pack will just be assembled out of mass produced cells from China.

£14k seems steep, I wonder what sort of capacity it is? LiFePO4 cells are getting cheaper - I’m surprised MB haven’t foreseen these sorts of issues and planned ahead to presence their reputation and customer buying confidence etc.

Obviously they don’t want their cars to last forever, but they need to be able to justify their prices and stable residuals are part of that model.

Have you looked at any independent hybrid/EV type specialists who maybe able to advise on other options aside from main dealer - ie replace battery only?
There's an issue with the first generation HV batteries - they hardly make them anymore and MB charge the moon for them.

See also:

eBay is the way to go.
Guy with a Nissan Leaf had his batteries changed in Holland for 4k, I don't have any details though but it has to be worth shopping around.
I think the issue with the ops pack is that he has an "Isolation fault" This is where the BMS detects a high voltage outside of the internal battery structure OR too low a resistance between internal and external points.

This is designed to stop parts of the car becoming live at 100+V DC. So whilst a dodgy cell that is below capacity could be replaced, this needs a bit of further investigating/repair. Usual cause of this type of fault is water ingress. I am not sure of the possibilty of fitting a used battery and programming ETC but knowing MB it will probably require reading/writing individual chips inside the BMS to transfer the "identity". Still probably the best way to go.
Exactly, the battery pack as a unit is very expensive from MB but I suspect as time goes by there will be some appetite for a service to diagnose and rectify rather than replace the entire thing.

It’s a bit like binning an engine because of a fault with one cylinder that could be relatively simple to repair.

BBA reman, where are you? :)

Users who are viewing this thread

Top Bottom