Battery Disconnect Switches

If you leave your 530i parked for extended periods, the battery will be drained by the alarm and other systems.

I have learned that some cars are fitted with battery disconnect switches. Here is a collection of links to these products:

http://www.odysseybatteries.com/hella.htm
http://www.flamingriver.com/switches3.htm
http://www.moroso.com/catalog/catego...?CatCode=42225
http://www.mgcars.org.uk/electrical/body_switch.html

The last link is a how-to article. It also shows a switch (available from JC Whitney) that mounts directly to the battery terminal.

The "most engineered" system seems to be the switch from Flaming River. This one has a key you can take with you.

Anyone tried any of these systems? I guess the first puzzle would be, where to mount the switch?

Welcome your thoughts on this.

Regards, Michael

Flaming River offers two switches. I purchased the one with the key, but if I were to do it again, I would just use the one with the T-handle. It is a sealed unit, which is a good feature since sparking is a concern.

The switch mounts behind the battery, very neatly. It has solved the problem of the burglar alarm running down the battery.

I now keep a flashlight in the trunk to make it easier to find and turn the switch in the dark.

Be sure to disarm the burglar alarm before using the kill switch to turn the battery off.

Will post a photo when I get a chance. Very happy with the product, and with the neatness of the mounting.

Excellent! Thanks, Michael!

Does anyone know if you disconnect the battery, if when reconnected and started, there is a "re-learn" process for the ECU on a E39? I ask, because that is definitely the case with some cars I have owned. Typically you restart without touching the gas pedal (as normal), and then don't touch any controls or gas pedal for anywhere from several seconds to several minutes (usually outlined in the manual). I have not seen such warnings in the owner's manual for my 540.

Dave