I'm not 100% sure the Optima is an update rather than just a direct replacement. I believe the Panasonic battery is the same construction as the Optima (just can't remember where I saw this info) and that Nissan is now recommending the Optima instead, perhaps, because it's easier to find as it's stocked by most auto parts stores in the US. I'd be interested to see what comes as OEM in the 2009 or even the last of the 2008's.

Both the Panasonic and the Optima are "absorbed glass mat" batteries:

http://www.daviddarling.info/encyclo...glass_mat.html

I think that's why you have to be careful on how you charge them.

 

The TSB doesn't indicate the exact model Optima battery Nissan recommends but it does show one with a red top. I was looking at the Optima website and the red top batteries aren't the deep cycle version - the yellow top models are.

http://www.optimabatteries.com/optima_products/

 

If that is the case it's very disappointing news. Why does this battery need ANY cold cranking amps? As far as I know, it does not turn the engine (there is no starter motor in the NAH). So it needs to hold a charge for prolonged periods of sitting, and it should be able to operate the 12V devices for long cycles where it may not receive a charge. Perfect application for deep cycle batteries! I have used Marine batteries in my truck (which is used for emergency services and has an 1800W 120V inverter) and never had a problem. These batteries far outlasted the original equipment "thin plate" battery in applications that put prolonged drains on the battery. (sitting hours with emergency lighting on and using 120V devices via the inverter)