I have the same Battery Tender as well. I've been using this for years on my 1987 Buick Grand National without any problems. Just plug it in and forget about it.

By the way '530inOK', thanks for the tip on pulling up on the hood switch. That should solve my high battery discharge message each time I start the car after sitting with hood open for several days.

 

Finally i am back after 8 weeks of vacations and battery tender did its job,,, the green solid light was ON when i came and car was up and running...

Thanks to all for suggestions

 

Great car combination. I have a '87 GN and a 5 too ;-)

 

+ 1 except that the leads to the tender unit fit nicely in the small opening between headlight and body so I can close the hood completely. After this cold weather has passed I'm going to arrange the leads connected to the positive under hood terminal and ground connection so they snake out to behind the grill area, fit a plug with a snap over cover, so I can plug in the tender w/o even getting underhood.

 

Thanks a ton for this thread. The instructions were great. I have been driving my cpo 528i infrequently. On my last long drive - 150 miles, I probably left my Bluetooth in searching mode, which drained out the battery. After jump starting, I drove for half hour. But it did not build up the charge. Got the battery tender and after fifteen hours the light is solid green. Hope that takes care of it.