Battery replacement time?

[LisaLannister]

I know this may be a very naive question, but shouldn't tender me attached to the battery?

[Emmrbee]

Originally Posted by LisaLannister

I know this may be a very naive question, but shouldn't tender me attached to the battery?

Not on this vehicle
Have never removed my battery from my Z4M or the previous 3.0si in the 10 years that I've owned them. I prefer not to remove the power from the vehicle as it sometimes causes problems when reinstalled.
The BMW version of the battery tender plugs into cigarette lighter outlet.

[bosstones]

Originally Posted by LisaLannister

I know this may be a very naive question, but shouldn't tender me attached to the battery?

Directly or indirectly? There are jump points under the hood that provide an electrical path to the battery and chassis ground. Electrically, it's no different than hooking up directly to the battery. It just comes w/ less hassle. There is also a cigarette lighter option, too.