Ctek/Bmw Charger

[enuff_zed]

just for my understanding, why are people connecting to these terminals, rather than the battery terminals?

You are right of course on an E85.
However sometimes it comes down to something as simple as the distance to a plug socket and whether the car is nose in or tail in.
In addition, running a lead into the engine bay and then locking the car up is slightly easier than into the boot, where there's no obvious gap for a lead to come through.

[Ed Doe]

Thanks for the reply - I was wondering if there was something I was doing wrong - for me i've found it fine running either through the boot, or one of the doors has worked ok!

[Johnbmwz4]

I thought you had to use the terminals in the engine bay on E89s due to the BMS module. Charging straight to the battery by passes the BMS module.

[B21]

Thanks for the reply - I was wondering if there was something I was doing wrong - for me i've found it fine running either through the boot, or one of the doors has worked ok!

The E89 has IBS..intelligent battery sensor on the battery terminal, part of a pretty advanced regenerative battery ‘ alternator system that uses accurate battery charge state for a myriad of different ECUs across the car…

If you charge the battery via its terminals you confuse the charging logic calculations..so the engine bay terminals are the only approved method of charging..

[Ed Doe]

There we go, knew there was method to the madness! Equally pleased to hear it doesn't apply to my old nail too, as I've been charging it on the battery..!

[B21]

There we go, knew there was method to the madness! Equally pleased to hear it doesn't apply to my old nail too, as I've been charging it on the battery..!

I’m just staggered at how complex these cars are..I thought things went high tech when we got capacitor discharge ignition…

Trying to do mods on these cars gets TFD cause so many bits are micro processor controlled and then there are multiple data busses varying signals everywhere..and there’s no documentation

[enuff_zed]

I thought you had to use the terminals in the engine bay on E89s due to the BMS module. Charging straight to the battery by passes the BMS module.

You do, but the OP showed photos of his E85 engine bay so I replied in that vein