Trickle charging 8 series

[wcl4]

This may seem obvious to most, but my cigarette lighter trickle charger doesn’t seem to work anymore so I’ve begun exploring other ways. Looks like most people have said to use the jump start posts to connect the trickle charger. But looking under the hood, the negative post is obvious, but I was unsure of the + post.

Am I correct in circling the red as the positive and the black as the negative?

[rjjablo]

Thats correct

[petejk]

This may seem obvious to most, but my cigarette lighter trickle charger doesn’t seem to work anymore so I’ve begun exploring other ways. Looks like most people have said to use the jump start posts to connect the trickle charger. But looking under the hood, the negative post is obvious, but I was unsure of the + post.

Am I correct in circling the red as the positive and the black as the negative?

That’s right - exactly where I hook up my charger to. Has kept my batteries charged while my car has been garaged (for too long..!)


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[wcl4]

Thank you. There’s no + indication or red color so I wanted to be sure.

[petejk]

You’re missing part 5, which has a +ve symbol on it

https://www.realoem.com/bmw/enUS/sho...diagId=12_0382


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[Red Racer]

This is a good location jumping or quick charging. For a permanent connection, I hard wired my charger to the rear driver's battery. When I go for a drive, just disconnect via the plug. This way there are no wires to burn in the in engine compartment.

just my 2 cents...

[Auraraptor]

As mentioned, your intuition was correct but your car is missing this: https://www.ecstuning.com/b-genuine-...r/12521724375/

Of random aside, the same cover (different part number but similar design) in my E38 does not have the letters painted red, rather just a boring all black plastic.

For charging, I use the left (driver side) battery on a trickle (CTEK) charger as I can't close the hood easily with charger connected (they had a habit of popping off if not positioned just right).

[Reell]

Let's get to the bottom of this. My cigarette lighter plug stays on independent of key position. It connected directly to the battery. if you're unable to trickle charge the battery through it, there is a great in the circuit somewhere. Most like the fuse. You can easily verify this with the cigarette lighter itself prior to checking the fuse.

Relevant information. I read many posts regarding concern of wire burning using cigarette to trickle charge the battery. Foremost, trickle charging implies one to two amps at most coming from the charger. The cigarette lighter receivers in older cars have a 20 amp fuse in line.newer cars have 10 amp fuse. Either case, the wiring is more than capable of handling 2 amps trickle charging. I suspect folks aren't using a "trickle charger" or have the wrong setting on the charger causing over heating and or wire melting.

[toomann]

This is a good location jumping or quick charging. For a permanent connection, I hard wired my charger to the rear driver's battery. When I go for a drive, just disconnect via the plug. This way there are no wires to burn in the in engine compartment.

just my 2 cents...

me too!

[TxGR8White]

I keep both E31’s on an electronic trickle charger. One is connected via the left rear battery and the other via the posts under the hood - it does NOT matter which way you do it.