Originally Posted by jfoj

All this discussion about removing the battery cable while the engine is running really cracks me up and is really so stupid.

The only reason this was ever done back in the 60's & 70's is people did not own a multimeter and it was a backs woods way to test for charging.

Why this is even discussed or considered in 2015 when you can buy a multimeter for the price a a few cups of Starbucks and possibly risk damaging or even glitching a module is not even worth the discussion.

Especially when many of the BMW models have a built in Voltmeter and you do not even have to buy anything, open the hood or get out of the drivers seat.

A Voltmeter is really all that is required to get a very good idea as to what is going on with any battery or charging system. Yes, having more than a Voltmeter or tools that can verify AC ripple, measure Amerage and apply a load is all fine and good, but if the charging system or battery can meet some basic Voltage measurements, it is pretty much the case that things are working correctly and in good shape.

So anyone that wants to disconnect their battery cable, go ahead, I believe the more knowledgeable crowd would recommend that this not be done.