German/English cars

[jc1kz]

Just a rhetorical question here...Why do all BMW/Mercedes/Jaguars/Audi cars fail to start after they are left for just a few days?....I own '94 MB 280C/'00 Jaguar XJR/'04 BMW 325ci ZHP/ '08 Toyota Solara Sport...I went on vacation for a week, and of all these cars the only one that started right up was the Toyota....I've had to have the others started by AAA and was recommended to get battery tenders? I love my foreign cars, they drive great, handle beautifully...but a "pitas" when it come to starting after a few days (five or so). Any way just wondering....just my two cents

[flyfishvt]

Can't blame the car for a weak battery caused by it sitting idle for long periods. Battery tenders pay for themselves quickly. Batteries do not like to become fully discharged. The quickest way to kill a brand new battery is to let it discharge a few times.

[shogun]

I have no problem with that, not with the 11/88 E32 750iL and not with the 98 E36 M3. Can leave the cars at the airport for 2 weeks in the parking lot and they start w/o problem.
In case you do not use the cars that often, use a battery tender. In case you park the cars outdoors and there is enough sunlight, use a solar battery panel with cigarette lighter adaptors. These are small solar panels that plug into car cigarette lighters, all are small and designed to maintain batteries that have no load. They are not meant to re-charge drained batteries.

[MarcoZandrini]

I've left my last BMW, 2001 330Ci, for more than 2 weeks and he ("Fritz") started right up. These cars are rolling computers and don't like whacky voltages. That means your battery has to be in great shape.

[dhurley34]

Some batteries develop a parasitic drain within the batteries cells themselves after a few years. Nothing to do with the vehicle. All of my Germans have started right up after sitting for weeks. Even the diesels.

[Andpaw88]

I have E46 330D produced in 2003 and still with the first battery. I had no problems with it except one time when I left the lights on. Sometimes stands for 1-2 weeks and is still ok.

I think you should compare the battery voltage when it is connected to the voltage when it is disconnected (the car should be in a sleep state). Maybe something is badly connected or broken and gets charged even though it should not.

I've left my last BMW, 2001 330Ci, for more than 2 weeks and he ("Fritz") started right up. These cars are rolling computers and don't like whacky voltages. That means your battery has to be in great shape.

Cool name, I'm used to say that my car is my lover.

[Leothelion092]

Yeah there's def something wrong. My car had to sit for 3 weeks due to transmission oil cooler failure and I didn't have the time or parts to pump the transmission to make sure no coolant was still in it so I had to wait and then trailer it to my nearest mechanic with a machine flushing system to really get all the coolant contaminated fluid out. After I got that all done car started up right away. No hesitation or anything. As a matter of fact I actually had a Bluetooth audio player connected that constantly had power to it even when the key was out, and my battery is from 1/2013! I should probably change the battery out pretty soon here but so far so good. Especially with these cars batteries are one of the most important things to keep in tip top shape. Like MarcoZandrini said, they're rolling computers.. I built a desktop computer before with meager power supply and it wouldn't even be able to do basic things like play a YouTube video without freaking out. A computer needs a good power supply to make sure all components are working correctly.

[Honolulu]

Bought my '02 325xi after it had been sitting for months (kid lost the keys) and it started right up. I vaguely recall that it didn't sound like it wanted to do that a great number of times, but without subsequently charging the batter, it's now been seven months with no issues (related to the battery).

Yes for parasitic draw. There are posts that address using an ammeter to discover the flowing amps, but you have to wait until all the car's systems go to sleep. It's a lilttle while after you turn it off, maybe 15 minutes, but don't trust that number, do your research. OTOH if the battery drain does not recur, skip it.

Many shops that sell batteries will load test your battery for free, on the (sometimes very good) chance they will sell you another one. I have used their services a few times.

[Eaglesail]

Did the above mentioned use 'SU' carburetor....and also, and unrelated..but also maybe too incorporated 'LUCAS' wiring systems too for...and including Rover, Triumph, MG, Jaguar, Bentley/RR and ..a host of others???....Hmmm! ....German cars never to my knowledge used anything but German made parts before ww2. VW explored foreign markets for out-sourcing first...BMW seemed more conservative...but now today who knows? BMW's are being built in the USA south!

[jc1kz]

Okay, after reviewing the suggestions here, I purchased new batteries and new trickle battery tenders. I Will be setting them up tomorrow...Thank you to all that replied with positive suggestions.....

[Mjbrox]

I leave my 96 Land Rover with a junk yard battery sitting for months in the winter, and it still starts.

[curry]

I just got back from a five week trip to Europe. Started right up. No hesitation and no battery tender. Original battery.