Originally Posted by Marki_GSA
Can you link to figures for the 1A per headlight? Current figures would have the actual light out put in lumens a fair bit under a normal halogen. Personally I think the LED lights will be neared 3A, more than happy to be proven wrong though.
As I said earlier what if you don't have LED as many don't? They don't come with a bigger alternator to make up for it.
Valid point about the 2 spark plugs that will save a bit but then you have the added synchro throttle bodies and all the other electronic stuff the older bikes don't have.
Adding to the subject:
The GSLC not only has a new smaller alternator but also a new smaller battery (12 Ah).
In spite of very likely differences in watt consumption of the new versus previous model, the major reason for a change in battery capacity and, therefore, alternator capacity is the new starter system that uses much less energy to start the engine due to the new decompression system.
Although I find cjack's
calculations perhaps too optimistic regarding LED consumption and Marki GSA
more likely closer to the actual real value, the fact is that to know the real values one has to either measure them or get BMW's specs. The first are most likely easier to acquire...
What I think we can safely assume is that there are at least 5 amps available to the user as this is the limit of the accessory socket and another 1 amp if one doesn't use the GPS and an additional (estimated ) 3 amps if one doesn't use the original auxiliary lights. Most likely there is more watt reserve available, however, how many extra watts are available is, without measuring or BMW's specs, a wild guess.