Red Battery warning light

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C63mberley

Member
Joined
Dec 27, 2017
Messages
47
Location
Camberley
Car
C63
Evening all,

Driving home this evening and a red battery warning sign appeared on the dash.

Hoping some of you learned folks can tell me what the likely problem could be.. and what I should do next please.

Many thanks.

W204 2013 C63
 
Not a chance this could be alternator related?
Is it worth getting it connected to diagnostics?
 
Check battery voltage first, likely as a 2013 car it’s the original. Have you got a battery condition tester? If not try to borrow one - these cars eat batteries so 5 years is not at all unusual.
If it’s not the battery then yes of course diagnostics and it could be the alternator or ..
 
Sounds like the battery needs to be replaced.
This time of year with the need for lights on, heater on, damp mornings, etc the battery gets hammered and any weakness will soon show.
Depending upon the length of your journey it may well need a trickle charge once a week to maintain full battery health.
 
Defo sounds like battery is fooked.
I managed to get 10 years and 105k Miles out of my battery on previous CLS500, but then had to replace battery and alternator together. If you’ve a local Halfords they will be able to test the battery voltage for you[emoji106][emoji2536]


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Have you got a voltage meter to test the volts before and while starting? I had a similar problem a couple of years ago where I took the battery off and charged it overnight and it was fine throughout the winter till I sold it a year later.

I've recently bought an icar diag reader that I can plug in for you if you want that measures voltage. I'm nr Hook so not a million miles away.
 
The one time this happened to me (on an Astra Estate) it was the alternator failed. As mentioned above, Halfords can check the battery and the alternator - when I had a new battery fitted to my 968 cab a couple of years ago they also tested the alternator for me FOC.
 
Charge light on with engine running normally indicates nil output from Alternator.
Check drive belt not broken / slipping. If engine starts, check voltage with meter, should be 13.8 / 14.8 ish.
 
Thanks everyone. Especially those offering their help.
Think I'll pop into a local Halford and ask them to check the battery.
If it's buggered, Euro have a Bosch for £102 after discount.
 
If the battery is knackered, you might want to find out why - your car isn't that old.
 
Just a thought...
I don't suppose my Merc Roadside Assist cover can be used in any way for this?

Thanks.
 
I had that it was the alternator, I'm still on the original battery after 10 years !!!
 
That battery warning can appear for reasons other than a bad battery. Most likely culprit is the alternator not charging. I had the same warning recently on my own car, but the power steering failed at the same time - reason was a shredded serpentine belt.
 
My red battery visit workshop comes on after being left standing for a few cold days when first started. If I urn the engine off after 30 secs and restart all I normal again, indicating that only the slightest amout of charge from the alternator is enough to clear the fault. I don't get any "convenience features temporarily unavailable" messages (which I used to get on my 211 when the battery was quite old), and heated seats for instance work from first start up. From all this I surmise that its a warning for the auxiliary battery which might even be the original (12 tears old!), so a new one is on its way. As your light comes on whilst driving I would say its more likely the alternator.
 
Quick update on above. Gen MB auxilliary battery arrived today (£73). Fitted it and all was well. Removed the old battery and as I suspected it was the original stamped week 22 05. so 13 years old and hardly surprising it was showing signs of giving up!!
 

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