Solar Powered floating battery charger??

[lostbeachbum]

So, I have a couple of questions regarding how to maintain my car battery fully charged between long periods of non-use. I recently got into my car to go out to a local car meet and found myself with a dead battery which prevented me from going to the meet. This got me thinking about preventative measures. I currently live in an APT and do not have the ability of using a 120v floating charger. I started looking at solar powered battery chargers but also started reading about how overcharging a battery could do just as much damage as letting a battery fully discharge.

I was thinking about this idea. using a VW solar Panel ($20.00) and a OBD2 to BMW 20pin adapter(cheap)- Is there a 12v port on the BMW 20pin adapter in which this solar charger could charge the batter?

what do you guys think and or recommend?As far as cost I would like to spend as little as possible.

[Keith M]

I have a solar charger/battery maintainer that I use on my trailer. My brother also uses them on his sail boats. Not cheap at $150 but it works well and I've not had any problems. The company is Granite Digital.

[TurboJake]

Why not just take out the battery, and take it into your apartment to charge/maintain it, or disconnect it every time you leave?
That's the cheapest answer.

[Fusion]

Yea, or make a main positive on/off switch.
I have to install one too because I don't DD the 30.