Auxiliary Battery Malfunction

[Louisgcl]

My ride: C200 Sport (PI) Latest model

Hi C- Class owners, I having problem in my ride, It keep showing auxiliary battery malfunction even i press ok. Kindly advice whether does C200 have any backup battery? Please advice any workshop that is specialist in this. Thanks 

 

Appreciate your advice.

[johnphua]

Sometimes, vehicle park too long didn't use (example: parking at yard pending inspection, waiting for buyer) will result battery malfunction. Our sponsors MBM or optima etc should be capable doing this simple work

[dyeeng]

The auxiliary battery is the one in the front. Normal battery life span between 14 to 18 months. Tell tale sign of battery failing: sudden dim of lights, double cranking on start, jerky ride.

Change of battery, as soon as signs appeared is always better than having to tow car to WS or wait for AA truck to come by (waste of time). Save lots of agony.

[jtang]

Bros....u are barking on the wrong tree. Aux batt is NOT the main batt found under the hood. It's a small 12V batt used for the Eco start/stop feature. It's found behind the glove compartment of a CLA or A class. Not sure where it's found in W205...I believe it's somewhere there too. Even though the warning sign shows a fault in aux batt, the car can still start up & move normally as that relies on the main batt. 

Who can fix this? Better go back to C&C...

 

looks something like this...

 

[dyeeng]

Bro, the main battery is usually located in the boots while the one under the hoot is the auxiliary battery. At least that's what I learnt from C&C WS and, I think, it is also mentioned in the owner's manual..

Previously I thought that whatever under the hoot (in the main engine compartment) is obviously the main battery...

[jtang]

For W205... The main batt is under the hood in the front lah.

 

[MBENZ]

Certain cars have 2 battery, 1 in front and 1 in boot. In that case, front is starter battery and boot is main battery to power all your barang barang. 

Some battery in the boot is located in a hidden compartment behind the rear seats (like the s class). it's not placed next to the spare tyres. So u may want to be sure if there is a boot battery.

If your car only 1 battery , it powers everything including starter, just like jap car.

Aux battery is a small battery under side dashboard. To power your ecu. Usually it can last a long long long time

[Angchug]

Need help ! Can anyone advise where I got get the auxiliary battery for W205? 

I need to replace it . Thank you in advance 

[Angchug]

I went to PAS Auto the MD parts supplier. They said is not a real battery. Just a voltage converter. 

I struggled to locate it. Anyone know where is the location? 

[Angchug]

Finally got it done. The ‘Auxiliary battery’ which is actually a voltage converter unit and located infront of the passenger floor. After changing you need to do a reset. Cannot DIY. 

 

[Edisonaldo]

Hi Angchug, 

Did u face this problem, everytime the car restarts after start-stop mode, the radio restarts itself.. 

Changed the main battery but problem still persist. 

Should i change the auxiliary battery? 

How much did yours cost and the workshop u went to? 

Thank you very much 

[jasminejordan]

this is common error faulty for Mercedes, i think you need to replace voltage converter like other forum members suggested, you can buy it here https://xenons4u.co.uk/mercedes-benz-a2059053414-voltage-converter.html or any other shop 

[Jim]

What's the cost to replace the auxiliary battery. Mine is a W212.

[Darth Revan]

On 3/5/2020 at 10:04 PM, Jim said:

What's the cost to replace the auxiliary battery. Mine is a W212.

 

I got my W212 auxiliary battery replaced for $180. The battery is located at the trunk.

[unkermobil]

On 9/13/2016 at 11:58 PM, jtang said:

On 8/23/2020 at 1:40 AM, Darth Revan said:

 

I got my W212 auxiliary battery replaced for $180. The battery is located at the trunk.

 

Can u share which workshop did u change your Aux batt at? 

I recently (August 2020) serviced my W212 at C&C, and they highlighted that my Aux Batt should be changed as it is > 2 years old.  
Was quoted "about $600".  So I decided to KIV... 

[kepiting1sg]

On 9/17/2020 at 10:01 AM, unkermobil said:

Can u share which workshop did u change your Aux batt at? 

I recently (August 2020) serviced my W212 at C&C, and they highlighted that my Aux Batt should be changed as it is > 2 years old.  
Was quoted "about $600".  So I decided to KIV... 

For my battery replacements (not aux), I go to Khai Wah Batteries 453 Tagore Industrial Ave

See boss Fred for advice

[Darth Revan]

On 9/17/2020 at 11:01 AM, unkermobil said:

Can u share which workshop did u change your Aux batt at? 

I recently (August 2020) serviced my W212 at C&C, and they highlighted that my Aux Batt should be changed as it is > 2 years old.  
Was quoted "about $600".  So I decided to KIV... 

I went to Khai Wah Battery & Tyre @ 453 Tagore Industrial Ave S(787824).

[unkermobil]

thanks for the recommendations!

Noob question here.... How do you know the AUX batt is about to die? 

Cos for the Normal Batt, u can easily tell when the cranking is sluggish. 

But for the AUX batt? What are the tell-tale signs that it is failing? 

[level z]

the best way is to get the mechanic do a voltage check with a voltage meter, that is the surest way.

[Darth Revan]

On 11/3/2020 at 8:52 AM, unkermobil said:

thanks for the recommendations!

Noob question here.... How do you know the AUX batt is about to die? 

Cos for the Normal Batt, u can easily tell when the cranking is sluggish. 

But for the AUX batt? What are the tell-tale signs that it is failing? 

1. your brake-hold function would not be able to activate

2. Eco-mode stop working (Yellow E sign)