My wife drives her car (2006 E60 530i) on quite a few short trips which results in a 66% battery charge and the associated electronic gremlins (passenger airbag warning, passenger seat belt light malfunction). So I bought a float charger and set about finding a way to connect it to the underhood terminals. I wanted something that I could connect the charger without having to open the hood. The path I chose is to route the cable around the cabin air filters (near the wipers) over the the drivers side hood gasket, across the shock tower and then to the positive terminal and the negative to the bracket for the power steering reservoir. Here are a couple pictures:


Note the ground connection as well as how the wire is routed past the weather stripping on the right:


Wire routed around the drivers cabin air filter:



When I want to connect the float charger, I reach under the edge of the hood by the wipers and pull out the wire:



Charger connected:


The charger that I bought (I also got the 25' extension cable):


One note, the cable that came with the charger wasn't long enough to make it out to the wiper area. I therefore had to splice a longer piece to it to make a total length of ~4 feet. Good luck!

 

I'd be interested to hear how you get on with it. On my car float charging with too low a current charger is counter productive. The increased voltage stops the car going fully to sleep, it then draws more current than I'm putting in! That is with a 0.8A float charger really designed for a motorbike.

 

CJCVette,

I like that set-up, but I was wondering if the end of the cable has flapped around and left wear marks by the windsheild. Could you please advise as to how it's worked out?

Thnx!

 

It appears to charge just fine. I left it overnight and when I checked in the morning, it had switched over to maintain meaning that the battery was completely charged.

 

I have had it hooked up for a week now. I just checked and there are no rub marks or otherwise. I don't expect there to be since the cable is plastic and light weight. One thing to note is that when I am driving the cable sits next to the drivers cabin air filter (see the third picture above). I only pull it out to charge it. Also, the hood is sealed near the windshield which reduces airflow from the engine (which keeps it from flopping around). There is some turbulent airflow from the edge of the hood, but I wouldn't expect much. Basically, it is a lightweight cable resting on plastic - not much to worry about.

 

Thank you for your reply.