Battery Life

[Scouser51]

Hi everyone, all I need to know is whether or not my battery after six years is at the end of its life?
The reason I ask is that I keep getting the message displayed Stop Car and let engine idle. So knowing I was doing a 2 1/2 drive the next day, I put the battery on a trickle charge overnight. By the morning as all 8 lights had been illuminated on the CTE charger I assumed all OK.
No it wasn’t because half an hour into my journey the same warning appeared, it did disappear after a while but as soon as I switched on the air on it came on again.
Having completed the return journey today (another 2 1/2 hours) the warning came back on about halfway home. Once home my Mercedes me app sent me a message advising the battery was critically low on charge. It’s currently connected to the CTEK charger again as I’m not using the car until Friday.
Is this a battery issue or something more ominous, I drive a 2018 E Class 220?

Many thanks for any advice.

 

[DSM10000]

It sounds as if the battery cannot hold charge but before buying one have you checked that the alternator is charging? It should provide around 14 Volts at idle.

 

[Scouser51]

I blooming hope it’s not the Alternator, wouldn’t know how to check the alternator but will ask a neighbour whose good with electrics!

 

[Scouser51]

Just a thought, if it is a battery problem it could be the auxiliary battery, where exactly is that located on my E Class?

 

[markjay]

I don't know what the issue is, just to say that the original MB-branded Varta battery can last anything from 3 years to 15 years, and so the fact that the battery is 6 years old is neither here nor there... you'll need to get the battery tested by a car electrician. My local KwikFit used to offer free battery testing, not sure if they still do that though.

 

[Chrishazle]

Halfords will test your battery and alternator for free, although you may need to book an appointment and chances are they will then try to sell you a new battery including extra for fitting. Take their free test offer then go away and think about what you need to change and where to buy what's needed!

 

[Scouser51]

Halfords will test your battery and alternator for free, although you may need to book an appointment and chances are they will then try to sell you a new battery including extra for fitting. Take their free test offer then go away and think about what you need to change and where to buy what's needed!

Thanks for the heads up

 

[markjay]

I don't know what the issue is, just to say that the original MB-branded Varta battery can last anything from 3 years to 15 years, and so the fact that the battery is 6 years old is neither here nor there... you'll need to get the battery tested by a car electrician. My local KwikFit used to offer free battery testing, not sure if they still do that though.

Meant to say "my local Halfords!

And they charged £5 for fitting the new battery (but that was a while ago).

 

[E55BOF]

If your car did two two-and-a-half hour drives without an extrernal power source connected to the battery, the alternator is charging at least some of the time. If it's faulty, it's only faulty intermittently. Either that, ot it's not putting out full charge.

If all eight lights illuminated after an overnight charge, the CTEK found nothing wrong with the battery. If it's faulty, it's only faulty intermittently too...

If either is faulty, my money would be on it being the alternator not charging properly. Your neighbour should be able to identify that easily.

 

[colinallcars]

If your car did two two-and-a-half hour drives without an extrernal power source connected to the battery, the alternator is charging at least some of the time. If it's faulty, it's only faulty intermittently. Either that, ot it's not putting out full charge.

If all eight lights illuminated after an overnight charge, the CTEK found nothing wrong with the battery. If it's faulty, it's only faulty intermittently too...

If either is faulty, my money would be on it being the alternator not charging properly. Your neighbour should be able to identify that easily.

Can’t you check the alternator by bringing up the voltage display? 12 volts with engine off, 14 with engine running. Sadly I can’t remember how to call up the display…..

 

[SpikyMikey]

Just a thought, if it is a battery problem it could be the auxiliary battery, where exactly is that located on my E Class?

There should be a sticker on the car (normally on one of the B pillars or fuel filler flap) with a QR Code on it. Scan this and you'll get the "Rescue Card" for your car which should show battery locations.

 

[oldguy57]

As post 10 look at the charging display to see if you're getting constant 14v plus on a journey. As above it seems to be a charging problem so checking the alternator is a first step. I'd also be looking at the belt and the pullies, if any of these are failing it can cause a charging issue.

 

[markjay]

There should be a sticker on the car (normally on one of the B pillars or fuel filler flap) with a QR Code on it. Scan this and you'll get the "Rescue Card" for your car which should show battery locations.

I wonder if the location of the auxiliary battery is showing on the QR code, on cars that are equipped with a capacitor (instead of the traditional Lead-acid battery)?

 

[Chrishazle]

On my 2008 S204 C220 with NTG4 Comand, ignition key to position 1, press and hold "answer phone, end phone call and OK" buttons all together, after about 5 seconds a menu appears, the first item is something like vehicle conditions, press OK and you get battery info, start engine and you see alternator output voltage and amps. Don't know if it's the same on your E class!

 

[colinallcars]

On my 2008 S204 C220 with NTG4 Comand, ignition key to position 1, press and hold "answer phone, end phone call and OK" buttons all together, after about 5 seconds a menu appears, the first item is something like vehicle conditions, press OK and you get battery info, start engine and you see alternator output voltage and amps. Don't know if it's the same on your E class!

That’s the one! Probably not 100% accurate but it’s a good pointer to a battery / charging problem.

 

[markjay]

For those who do not have the voltage display on the dash, there's always this (or something similar~):

https://www.amazon.co.uk/Charger-Adapter-Voltage-Display-Samsung-Black/dp/B08NGCXHFZ/

 

[SpikyMikey]

I wonder if the location of the auxiliary battery is showing on the QR code, on cars that are equipped with a capacitor (instead of the traditional Lead-acid battery)?

Good question

 

[OneForTheRoad]

A 2018 will most likely be the capacitor pack . The warning your getting though tells me it's the main battery and the safety systems on your car are seeing low voltage. Watch this to put the hidden voltage menu on .

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Another thing when you charge the battery , where do you put the charger clips ??

 

[BTB 500]

I don't know what the issue is, just to say that the original MB-branded Varta battery can last anything from 3 years to 15 years, and so the fact that the battery is 6 years old is neither here nor there

The one in my SL was fitted when I got it in 2004 and is still going strong The one in my Vito lasted 17 years.

 

[OneForTheRoad]

The one in my SL was fitted when I got it in 2004 and is still going strong The one in my Vito lasted 17 years.

I've just took my AGM off my 2018 GLC , previous keeper was a woman doing school runs , I could charge it to 100% and stop start would work ,after 3 days or so , no stop start and charger would charge from 20% . New battery and new capacitor pack fitted , I now have full stop start in all conditions. One thing I did notice was the original mb battery was Exide and not the usual varta brand. Might be a story in that??