Complete dead battery

[blackscooby]

Went out to the car this morning. Won't even unlock. Called MB Mobilolife and got in the car manually. Key in ignition, fuel pump whirs but that's about it. No starter action, just a click from a solinoid somewhere.

Yesterday I thought it was a bit slower when turning over, but nothing seriously bad. Very strange, it's completely dead this morning as it won't even turn on an interior light

Speaking to MB they suggested I did not attempt to put it on charge as it might fry something... DOH !

Waiting for Mobilolife now.....

 

[Benzowner]

There is a positive terminal under the bonnet which is normally used for jump starting and I would have thought it could be used for charging as well. Unless you were intending to dump some huge charge into the battery, I wouldn't have thought you would fry something, after all your alternator put out a very high charge normally. I would suggest your battery in dead and needs replacing and I know on a lot of modern cars if the 12v system is interrupted a lot of settings are lost. If you connect another 12v to the underbonnet terminal, you should be able to change the battery ok, but no doubt others will weigh in with easier suggestions.

 

[Gollom]

Sorry to hear about that. You've not exactly had an easy ride with that car have you?

Experiences like yours say a lot about MB quality (or not!) nowadays don't they

Steve

 

[blackscooby]

Issue resolved. Battery was completely dead. Reported 8v.
100Ah battery replaced by MobiloLife. Cracked straight up. Strangely it had died over night. I used the car at about 4pm yesterday.

 

[Rory]

100Ah battery replaced by MobiloLife.

Did they charge an arm and a leg?

 

[Benzowner]

Issue resolved. Battery was completely dead. Reported 8v.
100Ah battery replaced by MobiloLife. Cracked straight up. Strangely it had died over night. I used the car at about 4pm yesterday.

Thats how much is taken by the alarm system etc & with temperatures hitting zero, that will also take about 75% out of a battery, so if its suspect, it will loose all the charge

 

[blackscooby]

Thats how much is taken by the alarm system etc & with temperatures hitting zero, that will also take about 75% out of a battery, so if its suspect, it will loose all the charge

It's what I suspected to be honest. Temps went quite low last week in Cheshire, down to -2c for a few nights. Didn't have any issues at the time but certainly issues this morning !

Battery replaced FOC thanks to MobiloLife Would have been a rather expensive £130.

 

[GazCaff]

Issue resolved. Battery was completely dead. Reported 8v.
100Ah battery replaced by MobiloLife. Cracked straight up. Strangely it had died over night. I used the car at about 4pm yesterday.

Yep, batteries can go suddenly like that. I had one do that on a VW a few years ago. Just for peace of mind though, I suggest you measure the voltage being delivered accross the battery with the engine running.

http://www.mbclub.co.uk/forums/showthread.php?t=30472

 

[C240Sport97]

that's an amazing result .. is your car less than 3 years old?

Battery replaced FOC thanks to MobiloLife Would have been a rather expensive £130.

 

[BTB 500]

Battery is covered by M-B warranty on used cars too, they replaced the one on my R129 when it died the first winter I had it.

 

[television]

Batteries fail most at the start of winter, the car can be perfect one day and not start the next, what happens is that one cell goes high resistant and not enough current can flow to turn the starter. You can charge the battery and it will run fine all day then overnight, back to square one.

You should remember that alternators are not designed for charging flat batteries, severe damage can result . The car runs on the alternator (30% of output) 30% to drive the consumers in the car, the rest is there to charge the battery as needed.

Malcolm