Dead battery.

[Gary Toth]

Hi all,
went to work no problem car started as normal no issues, my car is a E350 blue tec convertible. Came back after a night shift at 0400 and not even the bleeper would work, opened with key and no door light so flat as. Now been having a hit and miss affair with the stop-start over recent months, and this was put down to the battery. So to my question can the battery just dump all its charge, then get jumped started and drive home perfectly normal and restart at home like it never happened as mine did. I am replacing battery as per Mercedes spec. its been starting in all that ice mornings we've down south no problem until last night, not a warning given, only the stop-start issue.
Your views sirs and ladies.

 

[bembo449]

yes batteries can fail just like that pal , assuming until then the car was starting well , replace the battery and go about your business

 

[Gary Toth]

but for it to resume as was.......almost taking the micheal.

 

[bembo449]

it happens pal , stop / start is a waste of , in my opinion

 

[Gary Toth]

I'm not a fan either, don't know if you can turn it off though?

 

[bembo449]

not a clue but instinct tells me it will be no on an MB

 

[bc100]

If you have a Blu Tec car then your battery can't be that old but a new battery is always the first port of call. Pre stop/start and complex cars I usually had ten years from a battery.

I always turn the stop/start off on every journey but there is an OBD port gadget (not a Mercedes part obviously) that will do that for you.
I think on mine it will only turn off in sport+ mode but when you start the car after four hours it reverts to comfort mode.

 

[Gary Toth]

The Dead battery was because i had left the hazards on at work, we have to drive through the yard so have to have them on
The shunter had told the office but I was 50 miles away by then and no messaged was relayed to me bless.
as it was 5 years old and could not be let down again I bought a new one, as per merc £230 yes could have gone cheaper but wanted like for like.
so mystery solved.

 

[Craiglxviii]

Auto Stop Start can be turned off but that is every journey, it’s hard wired in. It also doesn’t use the main cranking battery but a capacitor bank instead.

It’s surprising what little current drain will flatten a battery. I remember an open circuit boot lamp totally wiped out the battery on my old Astra overnight, baffled me for ages as it was intermittent!

 

[L John]

yes batteries can fail just like that pal , assuming until then the car was starting well , replace the battery and go about your business

Respectfully, I wouldn't agree with that.
For a battery to be completely flat in such a short time when it was previously fine and it recharges ok, it almost certainly has to be caused by an external current drain.
If a cell had failed it wouldn't recharge and then start ok.
As the stop start has been playing up the battery may well have needed replacing but stop start always seems temperamental even with a new battery. There are a lot of factors that are used to calculate if the engine is stopped when stationary.