I do charge the battery at least once a week with a Battery Tender, 1.25 amp 3 stage unit. About every other time it tops off in less than 1 hours and then sometimes it takes overnight to top it off. If my wife tells me she saw the battery symbol or I do I top it off as well. I have a battery tender lead under the charge port for easy access and charging.
While I agree that ultimately I think there is something wrong with the car, after reading that other thread it seems like there is no conclusive evidence as to what is causing the phantom drain and the lack of charge. My theory now is charging with the larger 6kw on-board charger doesn't give the system enough time to top off the battery. That coupled with the weird intermittent 800 mA load on the 12v battery is the problem. I have toyed with the idea of getting a 12v data logger, but honestly it is less expensive to get a better or more appropriate (deep cycle) battery and just charge it once in a while.
My long term hope is Nissan will figure out what is up with their charging parameters and tweak it before I get the next one, or maybe a software update on this car.
I suppose data logging the 12v battery might help my cause to get Nissan to do something about it and I like the idea of actually seeing it logged, but should I take the time and effort or just put a band-aid on it and move forward? That is the real question
This is the data logger I was considering
http://www.amazon.com/Lascar-EL-USB-3-V ... ata+logger" onclick="window.open(this.href);return false;
I have the temp and humidity one and it works great.