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"BMW - Positive Battery Terminal T-Post Broken"


BMW - Battery connector T-post


Summary: BMW's T-post battery terminal connector is might to work where jaws of battery connector are relatively open. If you break bolt, might get from eBay or do as I did and use the one on the negative battery connector.




BMW X5: model year 2000, 4.4i, 200,000+ miles.

Replace BMW battery with auto parts store battery.

Tightening positive battery terminal post, broke T-post bolt (had to tighten to point of breaking to get BMW terminal to be tight on battery post).

Apparently there is no battery post size "standard" and positive battery post on BMW battery must be a much larger than after market batteries.

Went to BMW dealer and they do not sell T-bolt as a separate part, have to buy harness from battery to electrical panel on rear wall of spare tire compartment ($$$)!!!

Researched Internet: same bolt used in VW and Volvo, so went to dealer. Did not sell separately.

Went to auto parts stores, did not sell.

Did find T-bolts for sale on eBay but all said not compatible with X5??!!. Probably a mistake and could have used but decided not to chance it.


My Solution:

While positive battery terminal wiring harness is unique or complicated, negative terminal is not.

Cut off negative battery terminal connection and replaced with auto parts store, heavy duty battery post connector.

Used T-post out of old negative terminal on positive terminal.

Found that the battery post was so much smaller than BMW battery that even at relative tighten of T-post, BMW terminal was not tight on post.

Went to parts store and bought lead battery terminal shim. This is a lead cap that fits over battery post to make it larger in diameter.

Used screw driver to open end jaws of BMW battery connector and after cutting lead shim, got BMW battery connector to be relatively tight on battery post with jaws of BMW connector pretty open.

Now when T-post tightened, BMW terminal nice and tight on battery post.

T-post design meant to work where battery terminal size is large and bolt has to be tightened only slightly.


Ron - Shared Knowledge Home