Battery

[isohail72]

Hi,
Can faulty battery can cause engine light? As Halfords check battery under the bonnet. And life come as 0%. But volts were 13.7 and car was not start. Which is the main battery in the s class?

 

[Stocious]

Battery can hold a surface charge, also if that’s the voltage of your battery with the engine off it’s been overcharged, possibly an alternator fault, when you try to start the car check what voltag reads cranking, if it drops too low while cranking, day below 5v it could throw lots of codes as most sensors use a 5v reference, that and any one of the modules in the car

 

[isohail72]

Battery can hold a surface charge, also if that’s the voltage of your battery with the engine off it’s been overcharged, possibly an alternator fault, when you try to start the car check what voltag reads cranking, if it drops too low while cranking, day below 5v it could throw lots of codes as most sensors use a 5v reference, that and any one of the modules in the car

Both batteries are original, Mercedes batteries. 14 years old. 2 workshops suggested battery is poor. But volts on a check good.

 

[isohail72]

Both batteries are original, Mercedes batteries. 14 years old. 2 workshops suggested battery is poor. But volts on a check good.

Which is the main battery?

 

[Stocious]

Both batteries are original, Mercedes batteries. 14 years old. 2 workshops suggested battery is poor. But volts on a check good.

Battery voltage is too high, start the car briefly and check the battery voltage with the engine running and post back here, also while your at it stick a meter on the battery and see what bolts it drops to when you try crank it,,don’t buy new battery yet if there’s something wrong with the charging system, someone will chime in I’m not sure how or what way the alternator regulation works

 

[Stocious]

The big battery in the boot

 

[isohail72]

The big battery in the boot

Here are some readings of the batteries. Not good.

 

[isohail72]

Here are some readings of the batteries. Not good.

 

[Stocious]

What’s the voltage with the engine running

 

[isohail72]

What’s the voltage with the engine running

 

[Stocious]

Seems ok, I’d be comfortable with putting a new battery in, go for it, Varta are good or Bosch

 

[OneForTheRoad]

If they are 14 years old . They will be about toast. Replace both . Winters on its way.

 

[zipdip]

Well the battery in the engine compartment is just to start the car,all the other things that happen in your car are from the big battery hiding behind the rear seat which is accessed by removing the hard carpet covered board from the boot,changing it is easy if you want to do it yourself.

 

[markjay]

If they are 14 years old . They will be about toast. Replace both . Winters on its way.

You (and previous owners...) got your money's worth out of these batteries... time to replace them.

 

[isohail72]

You (and previous owners...) got your money's worth out of these batteries... time to replace them.

Changed electrical battery in the engine hood

 

[John N]

Changed electrical battery in the engine hood

And?

 

[OneForTheRoad]

And?

Turbo actuator arm not moving | Engine

It is W221, no SBC!

forums.mbclub.co.uk

More threads than a seamstress

 

[isohail72]

And?

Under voltage for both batteries is not coming.