Pautab1

After leaving my 16 GTS sitting for a week and half, I started the car and a few blocks away and it threw a check engine light. My mechanic did a quick scan and mentioned it appears the battery is getting weak.

I understand the lithium ion battery has a lifespan of 10 years, and my battery is at about 6 years old so I’m surprised it’s going early. My mechanic said it’s common especially if they are not maintained well. How long has your lithium battery lasted?

Stenzel-Germany

Hi,

Had "problems" with the lithium battery.

Causes are the following:
Car charging system only charges up to 80% (You can write a book about the GT charging and protection system)
The lithium battery in the GT is only 60 Ah The battery has internal protection. Also until shutdown.
ithium batteries can also "debalance"

Cars that are driven less often are more likely to be affected.

My experience is that even good chargers don't really help. (Have tested several, including normal C-Tek)

What works is the MB charger.

If you have the original Mercedes Trickle Charger. (Only this one)

Connect.
Important for lithium batteries: Press the "Reset" button for about 5 seconds (until an LED lights up)
12 hours charging.
Repeat this 2-3 times. (Balance takes a long time)

Try it. You can always buy an expensive battery.

It is recommended to use the Trickle Charger preventively from time to time.

Assume that your mechanic meant this with "maintained well".
Otherwise there is nothing to service about the lithium battery.

Best regards

Stenzel

Pautab1

Thanks Stenzel. I checked the mfr date on the battery and it was manufactured in 2014 so we are approaching the 10 year life span so I think I will proactively replace the expensive battery

Stenzel-Germany

Hi Pautap1,

You can also install a regular battery at a fraction of the cost.
Then choose the largest possible capacity that you can build from the dimensions.
Depending on the manufacturer, there are up to 85 Ah.

The only disadvantage is the additional weight of approx. 20-25 kg.
And the lithium battery should be encoded. (Code: U98)
Otherwise you have a stored error.

If you replace the battery, would you sell me your old one? I will of course, cover all costs.

I would like to open this and try to replace the lithium cells. I saw an "exploded" picture once.
Think you can repair these batteries.


Best regards

Stenzel

Pautab1

Thanks Stenzel. Do you think a weak battery would cause a check engine light? (I think it came on when I turned on the heater)

If you install a regular battery, can they be coded? I was reading through the forums and couldn’t find an answer. I’d be happy to sell you the lithium battery if I am able to ship a battery to Germany.

Stenzel-Germany

Hi Pautap1,

A weak battery or the protective functions taking effect produce an undervoltage.
Each control unit, nozzle, relay, sensor, etc. is negatively influenced by undervoltage.
Some things are protected against this (e.g. sensors often run stock by 5V) some things are not.
An undervoltage can also generate almost any conceivable error code.
Of course also a check engine light.

You don't have to code the new lead battery.

A lithium battery is monitored / controlled via the LIN bus B15.
The front SAM notices the absence, because the battery LIN bus does not send/receive any signals.
At least one error will be thrown.

So should code out the lithium battery.

The safest way is: MB should remove the code: U98 (lithium battery) from the VeDoc and then update the front SAM.
This will then also apply to future updates.

If you could send me the battery that would be great. Thanks.
If there are shipping restrictions in USA, let me know, can give you an address in USA.

Want make a report on the repair.
Would also like to bring the capacity to the possible maximum.
There are MB lithium batteries with more capacity.
These have the same dimensions and use (to the best of my knowledge) the same internal parts except for the individual cells.

If it works, the community benefits. And I have a bigger spare battery. :-) :-) :-)

If not, little money and some time wasted. But at least i tried.


Best regards

Stenzel

Stenzel-Germany

Hi Pautap1,

You owe me dinner.
My pasta water evaporated while I was writing the upper post.
Then forgot the salt because of the stress.
Cooking is my world. :-) :-) :-)

Best regards

Stenzel