View Single Post
      12-05-2011, 07:54 PM   #15
Tom K.
Major General
Tom K.'s Avatar

Drives: '07 328iT, '13 Boxster
Join Date: Mar 2008
Location: Maryland

iTrader: (0)

I'll look in the Bentley manual today and see if they say anything about harming the IBS (-) or the Safety Terminal (+). I don't recall seeing anything in the owner's manual about it either. The owners manual of modern BMWs don't tell you anything about maintenance other than to go to the dealer for it, so I doubt BMW addresses something like float-charging the battery in the owners manual. [/quote]

The owner's manual does cover this indirectly under "Giving and Receiving Assistance/Connecting Jumper Cables":

Connecting jumper cables
Connect the jumper cables in the correct
order, so that no sparks which could
cause injury occur.

Your BMW has a jump-starting connection in
the engine compartment which acts as the battery's
positive terminal, refer also to the Engine
compartment overview on page
215. The cap is

marked with +.

My ancient Battery Tender works just fine when connected to the underhood terminals of both my 128i and 328i.