C220 d is failing to start, assistance needed please.

[Howard_silver]

I possess a 2012 C220 D estate; I approached it last nite, merely four hours after returning home in it, unlocked it with the remote key fob, everything appeared normal, entered the vehicle, turned the key - it was unresponsive! I believe there were some electrical glitches and noises within the dashboard, yet the starter did not activate, no dashboard lights illuminated, and there was no response. Secured it once more using the remote control.
I replicated the procedure subsequently, yielding identical outcomes (albeit now devoid of electrical anomalies and components, though I am not entirely convinced there were any), with no dashboard illumination, nothing.
Once more today, the central locking functions properly, yet there is no ignition.

I have taken a battery charger from my family as a precaution, although it seems illogical to me.

Where ought I to direct my gaze? Assistance required.

[Allan8932]

Ensure the battery is completely charged and verify that the terminals are firmly fastened.
Upon complete charging, if it fails to start, it is essential to have the fault codes analysed to determine the problem.
A Mercedes expert is undoubtedly ideal, yet you might require a mobile mechanic or electrician equipped with a code reader to diagnose the issue.

[Howard_silver]

The battery was charged, initially displaying 5% on the charger, and was increased to 90%, but it would not rise further; upon attempting to start, the mileage and other indicators appeared (which were absent during my tinkering on Friday night). No thing
Attempted to recharge the battery once more, reaching 5%, yet it surged to 90 instantaneously, still no results.
Attempted to leap from the vehicle belonging to my spouse, but to no avail. No indicators illuminated. The glow plug indicator, merely the typical digits within the speedometer that light up upon activation.

[clk320x4]

Attempt to install an additional battery. It appears that the installed component has malfunctioned, and the internal resistance may be hindering the donor battery from supplying sufficient power to initiate the start.

[Howard_silver]

Simply apply a battery tester directly to the battery located beneath a large plastic cover. This is 1-2 hours after the charger was last connected; it indicated 12.42, which aligns with the 90% the charger reported.
Evidently, I lack expertise, yet it seems the battery is functioning properly? 

[clk320x4]

Not obligatory.

It pertains to its performance when subjected to stress.

[Howard_silver]

Thank you, I will revisit this matter.

[clk320x4]

How did you attach the jumper cables?
Should I connect directly to the battery or to the jump start terminal in the engine compartment?

[ML350_Colin]

Is this the authentic MB battery? If that is the case, then at the age of 13, it owes you nothing—simply purchase a new one regardless.

[MrGreedy]

I have merely perused this discussion thread.

A few enquiries: for what duration have you possessed the vehicle? Have you purchased from an M-B dealership; has it been maintained by them and is it current?

I understand the vehicle is several years old, yet if it possesses a complete dealer service history, it might include their Mobilo Life coverage, which could allow you to request a diagnostic visit. I am confident that additional individuals will join, given the numerous terms and conditions; however, the primary stipulation is that maintenance must adhere to the schedule and be performed at an M-B dealership.

If that is not the case, are you affiliated with one of the breakdown services, such as AA or RAC, and do you possess home start coverage? Once more, you might be able to arrange for a technician to visit and diagnose the issue with your vehicle. If the issue extends beyond the battery and they are unable to resolve it immediately, you ought to request that they transport the vehicle to a garage of your preference.

The issue may lie with the battery, as previously mentioned by others; should you procure a replacement, verify the appropriate specifications for your vehicle (some models possess dual batteries, though I am uncertain about yours) and opt for an OEM brand such as Bosch or Varta; select a battery with a five-year rating. Although substituting the battery will undoubtedly pose no detriment, there exists the potential for other issues to be present.

To ascertain the appropriate battery type for your vehicle, input your registration number on the website provided below, navigate to the car batteries section, and it will specify the correct battery model for your car, along with a selection of compatible batteries from various brands; it is advisable to opt for one of the premium brands listed, yet it is prudent to compare prices as they can differ markedly between retailers (occasionally by as much as £100 for the identical battery!).

For instance, if a website indicates that your vehicle requires a type 019 battery, it is likely to present various options available for purchase; however, if you also explore platforms such as eBay or Amazon, or simply conduct a Google search for a type 019 car battery (this is merely an illustration and may not pertain to your specific vehicle), the results will yield numerous vendors, revealing considerable price disparities for the identical battery—thus, it is advisable to compare prices.

[MrGreedy]

https://www.eurocarparts.com/?utm_source=awin&utm_medium=affiliate&utm_term=ecp+homepage&utm_content=Skimlinks&awin+traffic&utm_campaign=Sub+Networks+78888&sv_campaign_id=78888&sv_tax1=affiliate&sv_tax2=815061&sv_tax3=Skimlinks&sv_tax4=forums.mbclub.co.uk&sv_affiliate_id=78888&awc=3997_1788184813_64d46b45c42ff93bbcd6aeac6ce160aa

[AMG33D]

A seemingly depleted battery can still provide 12.4 volts. AGM batteries do not accept a charge when they fail. You should install a new battery or, at the very least, procure one temporarily to determine if that resolves the issue. A nonfunctional battery will not permit charging via jumper cables.

One method to rejuvenate a depleted AGM battery is to detach the cell caps and introduce distilled ionised water into the cells, in an attempt to facilitate charge acceptance.

Attempt to loosen the live and earth connections and manipulate them slightly, then retighten.

[MrGreedy]

I assume you were referring to AGM!
Absorbed Glass Mat batteries contain an electrolyte gel that is retained within a fibreglass mat and, to my knowledge, are hermetically sealed.