marc777

Got caught out on Sunday when the car failed to start - actually the dash lit up like a Chrstmas Tree with 2 Brake failure malfunctions - and ESP malfunction - but in the end it just turned out it does that when the battery goes dead.

MB were out within the hour and jumped started it. Battery was fine after a couple of minutes.

Turns out that my daily commute of just 3 miles, with Xenons, heated windows/mirrors/CD/fan/phone/radar detector/ etc was just too much. The kids loaded a DVD without the engine running on Sunday morning just before setting off and that finished it off.

I've now turned off the auto lights (becasue they do come on in daylight).

I used to do this in the 70's with an old Ford. Hadn't expected to have to do it with my 2002 W211 !

Marc

marcos

Thats the trouble woth modern cars like the W211 Marc. Too many electrical items using too much power, bieng diesel of course the glowplugs will have been on and the electrical pre-heating elements for the heater.

marc777

Of course - I hadn't even considered the glow plugs -

Omer

Had the same problem myself over the weekend. Car flashed every malfunction warning from brakes, ESP, Display faulty, SRS to rear backrest not sure.

The breakdown service guys came out but said that the battery was totally drained so probably problem with rear fuse box.

Anyway to cut a long story short, dropped the car off at the dealers. Hoping am not given a huge bill at end of day!!

Gunite

This is why I always thought installing a large capacity deep cycle battery on these cars, in place of the standard one would be beneficial. These battery's are designed to withstand a slow current draw all day long.

sosh

My commute is only about 3/4 of a mile. Never had this problem with any Bemz, Thats a W210, W211 and 2 ML's. You may have had a bad battery

prprandall51

I looked into this a while back. Deep cycle batteries are great for long-term low current draw but their construction is different in order to achieve this aim. The contain a larger number of thinner plates than a starting battery. Under heavy loading - such as starting a large engine - these thin plates are in danger of over-heating. If they do, they buckle, causing an internal short.

I have purchased a Gel battery to overcome this problem in my Land Rover. The solid gel (rather than liquid acid) helps to prevent the plates from buckling, plus the plates are thicker. The downside is that they are very expensive, quite bulky and are mind-bogglingly heavy - mine is 47Kg (104lbs) - too heavy and too large to fit in the standard battery location (and this was a "small" gel battery).

In a standard car (with a pre-defined battery space) it seems to me the best bet is to purchase the biggest starter battery that will fit. However, most battery problems are due to a lack of charging time (resulting from short trips) anyway, as discussed above.
Philip

Gunite

I'm guessing the heaving loading, engine starting is not the main problem but, the fact they have to be used for this much more often in cars then boats. Where a boat with a large high compression engine may only have to be started once a week, and our cars every morning.
My car is not my daily driver so this still may be an option for me or others who don't use their car everyday.
My only question is if the battery does developed an internal short will this cause any damage to the electronic devices in the car.

marc777

The service guy said the battery was a gel type of battery.

He also tested it and stated that it no faults and just needed charging.

Marc

prprandall51

Hi Gunite
Fair comment about the usage profile. I am not a boat person - I actually assumed that boats fitted with a "leisure" (deep cycle) battery for lighting, TV, fridge, etc. also have a separate starting battery for the motor but I don't know.

If a battery shorts internally there is no reason for electronic components to be damaged within the car. The short in the battery will merely appear to the compoents as a drop in the voltage from 13.5V (standard, charged) to, say, 6 or 8 volts at the connectors, depending on how many cells in the battery pack up. This would not damage any electronic component (electronics are usually damaged by the application of a voltage to a pin where voltage should not be). As confirmatio of this, batteries expire all the time around us (usually every 4 to 6 years per car) and a new battery immediately sorts everything out. Electronic systems are not damaged by a dying battery (which often dies because of an internal short).
I should add that I am not in any way qualified on this subject beyond my own researches into batteries and personal experience and education.

Philip

SAguirre

My family and I have had many boats and I would strongly recommend against going for a deep-cycle battery. It sounds like a good idea, but a deep-cycle battery will not crank your engine like it needs to. Also, like mentioned before on this thread, if you pull too much power at once from a deep-cycle, you run the risk of destroying it!

On occasion, I (as a teen-ager) have started our boats with the battery switch on the wrong battery. The battery would barely crank the 350 CI (5.7 liter) V8s, but then the battery failed immediately after the cranking. That is why there are two distinct kinds of batteries and cars don't use Deep cycle batteries. Needless to say, I did not make that mistake again, but did not feel too bad when my father did it again after I did.

As per the original post, I have been driving my car this week to work and it is only 1 mile. I have never had any problem. I think that you must of had a bad battery, it happens. If you feel like it, search this thread for "battery maintainers" you will see what I have on my car for the times it sits for long periods of time.

Hope this helps,

Steve