OK, so it appears that I know nothing regarding the proper maintenance of my E300's battery while sleeping in the garage.

a. what is a good unit to maintain my battery's full charge. Yuasa and Battery Tender have been mentioned, what model would be best for the large E300 battery?

b. how often do I connect it (trickle charge). I've seen photos of the "Battery Tender" where people appear to leave them plugged into the vehicle all the time while stored.

c. I would imagine that since my vehicle is in a single bay garage, the garage would need to be vented, i.e. ajar door as the battery emits gases during use, be it charging or drawing current?

d. what else am I missing?