Mercedes Battery has black socket near Negative Terminal

[plls]

Hi

I own a 2017 Mercedes C200 2.0l car and I have to change the car battery. I ordered a new Bosch car battery from Eurocarparts but when I began changing the battery I realised that the new battery lacked a certain feature present on the original Mercedes battery.

As you can see below the original battery looks very similar to this. On the left side near the Negative terminal you can see some sort of electrical socket (it's the black socket) which is connected to some wire. However the new battery completely lacks this feature so I can't connect the wire to anything.

I'm wondering what's the purpose of this wire/socket in the car and if it's important? If it's not important can I continue using the Bosch Battery below or do I have to somehow get a replacement battery similar to the one shown below?

Thank you

 

[EmilysDad]

Hi .... welcome to the forum.

I can't see the socket you 're referring to so can't help ..... do you have a clearer picture?

 

[plls]

Hi

Thanks for the welcome

I've highlighted the area around the black socket shown below

 

[Snake Charmer]

Top battery is a Lithium Ion, I think the connector is for the CANbus connection to the car as there is a control circuit within the battery. The other battery is AGM chemistry so has no circuitry within.

 

[EmilysDad]

Hi

Thanks for the welcome

I've highlighted the area around the black socket shown below

Ah! I've never seen that on battery before. Maybe someone else might know what the wire that plugs in to it is for. Maybe you can make up a short lead with a suitable female connector at one end & an eyelet at the other that could be connected to the negative battery lead

 

[Snake Charmer]

 

[EmilysDad]

All the PPE ..... and a short sleeved shirt!

 

[Snake Charmer]

I'm wondering what's the purpose of this wire/socket in the car and if it's important? If it's not important can I continue using the Bosch Battery below or do I have to somehow get a replacement battery similar to the one shown below?

Fitting the AGM battery may need a coding change to prevent warnings on the dashboard. @alexanderfoti or @Steve@Avantgarde may be able to shed more light on the coding requirements.

 

[pgh13]

Are you sure it's a wire and not a vent pipe for any gases released when charging?

 

[ajlsl600]

If that's not a vent. It's prob latest scheme to prevent ur choice of battery!! And therefore ability to control costs. I struggle to understand any need for any "socket", connection other than the std +, - . But then I don't understand many "schemes" on modern cars, benz in particular.

 

[Larkone]

Its likely to be a a connection to manage the rate of charge to prevent the cells getting too hot - lithium battery fires can be be very destructive

 

[ajlsl600]

More complication to what was otherwise a very simple system, previously I believe a simple fuse dealt with that, not something built into a battery that cannot be maintained.