Battery voltage

[Merc mat]

Ok I have issues with no stop/ start
Not going green ,iv tested both battery the auxiliary is saying 12.8 and the main 12.00 I think at 12.00 it's a little low , but I didn't think the main battery affected the stop / start the car is a 2012 e220 ,

 

[Wighty]

Ok I have issues with no stop/ start
Not going green ,iv tested both battery the auxiliary is saying 12.8 and the main 12.00 I think at 12.00 it's a little low , but I didn't think the main battery affected the stop / start the car is a 2012 e220 ,

12 is almost dead buddy , what date is on the terminal

 

[malcolm E53 AMG]

I’ve found that the condition of the main battery on the 212 is a big factor in whether stop/start is available. I replaced my main battery last year and stop/start hadn’t been available for quite a few months prior now the indicator shows it’s available within a couple of miles. Incidentally I switch it off as soon as the indicator shows that it’s available to save the engine - acts as a good battery indicator though.

Varta or Bosch are the OEM batteries I used Tanya online to order mine, best price and next day delivery. Regardless of where you buy from top the battery charge up for a couple of hours before fitting it makes all the difference

 

[Gazwould]

Just replace the battery when it starts cranking slower , no stop strain is an excellent thing .

 

[Merc mat]

12 is almost dead buddy , what date is on the terminal

Not sure of date this is a picture of it , I do no it's never been replace , as it was my father in laws car,

 

[Blobcat]

Not sure of date this is a picture of it , I do no it's never been replace , as it was my father in laws car,

I'd have the tops off the cells and and fill with de-ionised water

 

[EmilysDad]

Not sure of date this is a picture of it , I do no it's never been replace , as it was my father in laws car,

The date is normally stamped into a terminal post in the same format as a tyre ie 4 digits, week number of the year & then the year number ie 5020 would be week 50 of year 20

 

[Tony Dyson]

From the picture the Date is Week 09 2012

 

[EmilysDad]

From the picture the Date is Week 09 2012

you're right .... I tried to enlarge the photo on my laptop but failed ... I could see it though on my phone.

At over 8 yrs old it's well past its best

 

[Blobcat]

From the picture the Date is Week 09 2012

 

[malcolm E53 AMG]

Yes 8 years service is good for a battery if you’re keeping the car I’d replace with the same Varta battery, shop around for price but Tanya take some beating re price and delivery

 

[Merc mat]

Thanks guys, so it looks like new main battery time, I did recheck the voltage direct off the battery and it read 12.15 , thats still a little low ?

 

[Blobcat]

Thanks guys, so it looks like new main battery time, I did recheck the voltage direct off the battery and it read 12.15 , thats still a little low ?

Very low - 12.6 is what you're looking for

 

[Gazwould]

Yes 8 years service is good for a battery if you’re keeping the car I’d replace with the same Varta battery, shop around for price but Tanya take some beating re price and delivery

Not necessarily .

Strongly consider buying locally in case of issues .

 

[Merc mat]

I'd have the tops off the cells and and fill with de-ionised water

Is it not a sealed unit ?

 

[Blobcat]

Is it not a sealed unit ?

Yes and no...
You can cut around the tops of the cells (the sticker) then use a chisel (or screwdriver) and hammer to knock the cell tops anti-clockwise to unscrew.

It messes the cell tops up but only cosmetically. You can then fill the cells up with de-ionised water and I expect the battery will come back to life.

I expect the tops of the plates will be completely exposed with no visible electrolyte at all.

Fill it up to just over the plates and leave it 1/2hr then measure the voltage again.