my 03 (original owner) with 68K miles still has both OEM original batteries. I have had no issues with starting or anything else should i just keep going until one of the batteries dies?? car is garaged both home and work, maybe that has helped them last 8 years so far. thanks for your help

 

I'm a firm believer of preventive maintenance. My 03 also has the factory battery, and the date on it was in 02..... so this week I will be replacing the main battery as a preventive measure. I will also replace the backup battery in the near future, as soon as I can find a suitable replacement.

While it is amazing that the factory battery has lasted as long as it has (mine only has 68k on it as well) I do not feel the need to push the limits of battery life and find myself stranded.

 

thats what i was wondering, will there be any warnings, or will i go to start one day an nothing. Its do for a D service soon, so i will have the dealer give it a check and make a decision based on there findings...

 

when batteries go bad there is no warning... my experience is that they fail when its really cold out or really hot..... extremes....

 

My 2003 spent 3 years in N.Y. with unknown conditions and about 4 years in my heated garage. Batteries went out within 6 months of each other at about 84 months.
You are on borrowed time

If you wait for a failure, it will be untimely. I have heard that the roadside assistance for OEM batteries is quite reasonable but still, better to be on your schedule than someone elses. OEM batteries are a dealer only item (I believe) but there are a number of equals for $100 to $250 for the cranking battery and $39 to $100 for the little aux battery. I definetly would get an AGM for the smaller. My 2003 had a vent line for the large conventional battery so that is how I replaced it. AGM is more expensive

 

Mine gave the bat warning and I replaced it with a new AGM from Carquest last year. Cost was about $195 and it was an identical battery made exclusive for European cars. The aux bat I provided enough info to find a replacement at Autozone/Napa and many other places around $65. 00

 

thanks guys for your input, while getting gas i ran into a MB roadside assistance tech who had a truck full of batteries, as he said its the season. Very nice guy, he put his electronic battery checker on the one in the truck and it checked out ok, but he said that 84 month thing too, he also recommended i call roadside since there would be no install charge for a new battery, and gave me a $40 off coupon.

 

How much do they charge if you have MB roadside assistance people change/replace the main battery with a similar OEM battery?

 

My car is 8 years old with 51,000 miles on the clock. I am the second owner. It was garaged nightly for 7 years with the original owner, unfortunately 5 motorcycles are filling the garage so the car is parked outside at all times. With the onset of winter I noticed the 'electrical consumers switched off' message was appearing more frequently (it had been appearing beforehand, but less frequently) so I checked both batteries. The main battery was showing output of less than 12 volts, the auxiliary battery was showing output above 12 volts. I decided that now was a good time to replace the main battery, I'll check the auxiliary battery again in six months, once the output is showing less than 12 volts, then I will replace it.

I enquired at the MB dealership and was quoted £150 for the main battery, and £90 for the auxiliary battery. Searching online I found the equivalent main battery Yuasa Professional 100 12v 70Ah 650CCA Car Battery for £75 delivered, and the equivalent auxiliary battery Yuasa YTX14-BS 12v 12Ah Motorcycle Battery for £52 delivered.

I've now fitted the new main battery, and even after being parked outside for more than a week covered in snow, and with temperatures below freezing for most of the week, the 'electrical consumers switched off' message is no longer appearing.

I personally wouldn't replace your main battery until you start to get the 'electrical consumers' message. I'd been getting it for quite a while and it wasn't a case of getting the message, then the car wouldn't start. You may find in your case you could get many more months, even years, before the warnings start to appear.

Cheers

Stephen