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Old 04-18-2011, 11:19 AM
tampamark tampamark is offline
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Location: tampa fl
Join Date: Jan 2009
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Mein Auto: 650 Sold - '12 Jaguar XK
Originally Posted by 645/333 View Post
I am interested in this charging from under the hood or charging at the battery?
I don't mean directly across the terminals on the battery, but using the connections in the boot area. The terminal in the engine +ve (red) is wired directly to the battery with no intermediate connections or circuitry.
The -ve being the body connection. Therefore there is no difference between doing the charge at the battery as opposed to the battery +ve terminal under the hood. What difference the impedance of the cable ??????? don't think so !
BMW officially sell wiring kits which connect directly to the +ve terminal of the battery and the _ve or ground of the body. They have plug connectors which can be put into the rear internal boot sill to allow the charger to be plugged in as a matter of convenience without having to lift the floor carpet over the battery compartment.
The IBS is not impacted by charging at either location...... so why are people so intent on saying only charge at the terminals in the engine compartment............ sorry but it does not make technical sense ????????
Your BMW is a control freak. It wants to know everything that goes on, especially when related to the battery. The TIS manual specifically calls for charging the battery using the jumper terminals so that the system can monitor the charge even when the car is off and you are using an external charger. That way the electrical current flows through the IBS circuitry.

Of course, if you replaced your battery and never registered it, then what does it matter?

I am not sure if the boot area is before or after the IBS circuit?

Last edited by tampamark; 04-18-2011 at 11:20 AM.
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