Is it safe to connect the couplers to the mounts under the hood or do they need to be connected directly to the battery? I will be away from my car for some time and the wife does not feel comfortable driving my car while I am away. Thanks.

 

Only connect to posts under the hood. I installed the optional quick connect cable as per attached.

 

+1
Best to connect to under the hood.

 

That is what I was hoping to hear. Thank you folks.

 

+2 .. I used quick connects so I could disconnect / reconnect the wiring easily.

The attached pictures are the set-up for my Z3; in this case it's a '98 so was connected directly to the battery posts as the electrics for the car are less complex than current BMWs. I duplicated the setup when I had my '07 530xi.

You can pick up the connectors at any Radio Shack. The little cap (visible in the second picture) protects the in-car connector when it is not in use. I used low-voltage landscape wire so I could extend the connecting wire to the car and not have to use an extension cord to the battery tender.

Pay close attention to polarity (when connecting to the car's under hood battery post) though most battery tenders have protection circuits built in.

 

Just my opinion, but backed up with some facts: I just lost everything we owned in a house fire from a built in charger in a bass boat. after talking to the fire investgators I will think long and hard about using these type of trickle chargers and the plug in scent modules used in a house because at least 3 of these guys who see house fires everyday said these 2 items caused a lot of the fires they see. I'm not trying to keep you from using them, just be sure there is a fire suppression system over the area where they are used, or that the vehicle isn't in your basement while you sleep above it because that almost cost me and my wife our lives.

I will always do my charging outside and during the day while I am close by just in case. I had the built in charger in 2 boats and 5 battery trickle chargers on my car collection which now are ashes ( not even good for scrap), this cost me a few million in lost corvettes and Camaros, and tools, boats clothes ect....

 

Out of curiosity, what brand chargers were you using? Guess it would be too little too late to say the company should be liable for the fire. Sorry for your loss but at least you and your family are safe.