I have a '99 C280.
I will not be driving my car for 4 months. what should i do from these 2 option?
1. disconnect the battery ? do you think the car would need to be reset again once the battery is connected again?
2. let someone warm up the car at least once a week for 15 mns?

what do you recommend? do you have any other option?

thanks for your help.

 

either way will be fine. if you disconnect the battery you may have to put in the radio cade again and normalize seats and windows. everything I have been taught about batteries though is that on average it takes approx. 30mins. to recover the battery from the power drawn to crank it. just make sure that the car is running to the full operating temp. and let it stay that way for a few minutes. had a guy bring in his R class the other day that sat for 2 years while he was in Dubai. ran fine just neede a new battery. I have a few project cars and i leave the batteries disconected when not using them.

 

The best thing you can do is go to you local battery or motorcycle dealer and get whats called a bettery tender. I leave my batteries in my jetskis and bike over the winter and just hook up and tender to each one. The tender is designed to charge each time the battery drops below a certain point and the turns back off and had a fail safe built in. So you hook it up and go. They are normally $35.

 

I like to use the type of charges that cycle the batteries versus giving a surface charge. Yes they are pricey, in the 100 dollar range BUT it's supposed to give the battery better long term life...who knows for sure...

 

I wouldn't leave it disconnected and the reason is simple. Even if you leave a brand new battery on the shelf for a long time they go bad and that is why there is a "shelf life" for batteries and if certain batteries don't move, the battery people will "rotate" them. The process is called Sulfation. This is where sulphur separates from the electrolyte and falls to the bottom of the battery and after a while it is high enough to short out the lead plates. This will happen if the specific gravity of the electrolyte falls below a certain reading, where the electrolyte turns more water than acid.
To cut it short it is suffice to say that it is better to either use the "battery tender" that ibgummy mentioned or have someone drive the car for 1/2 hour every 2-3 weeks or so.

Alan.

 

My 2002 C230 coupe sits under a mountain of snow all winter from December to April every year (since 2002). I just start it once a month and let it warm up to full operating temp.
Only had one new battery since 2002. I don't use a battery tender but think they are a great idea.
I would highly recommend that you NOT disconnect the battery.

 

Hi,
I have a battery problem with my 1995 C280. We bought the car new in 1995 and it still has less than 60,000 miles.

In the last several years, we've used the car less frequently and sometimes it sits for several weeks. In the last three years, we've had to replace the battery about five times. We've taken it to the dealer and to an independent mechanic. They both say the alternator does not need to be replaced.

The independent mechanic has said we need to drive the car at least once a week in order to keep the battery charged. He also sold us a better battery and told us not to buy the batteries sold whith the AAA road side service. He doesn't think they hold up.

Unfortunatley, the new "better" battery has the same problem the other batteries had. We had out of town visitors and the car was not driven for three days, the battery went dead. This battery is less than three months old. If it were the first battery, I might blame the battery. I think something else is going on and so does my husband.

Based on an experience his sister had in a Honda Accord, my husband suspects that the factory installed car alarm is draining the battery. He wants to permanently disconnect it. That would mean no car alarm and no panic button if I needed it.

Does anyone have any other ideas?

Based on over 15 years of C280 car ownership, we think it is a pretty good car. The only ding I would give it is that the electrical system (fuses, etc.) has been somewhat unreliable over the years. Other than that, the car hasn't really had very many problems. We did recently redo the headliner and replace the back speakers, which were rattling. We also upgraded the stereo with something that can handle an i-pod and bluetooth. We'd be rolling in style but for this battery issue.

I don't know if anyone is still looking at this thread so I'll probably start a new thread in hopes of getting some advice.

Thanks!