The OEM battery can't be that bad. I had my car in the cellar garage of a Ford dealer during 5 months in the winter (no heating, battery connected - i.e. everything you shouldn't do) while I drove a Ford car through snow and ice.
When I swapped the cars in spring I just sat in the NSX and started the car - the dealer couldn't believe it. He said he never had any ABS equipped car that stood for so long and started just like that (maybe ABS needs some mA in standby mode - don't know).
As the car is now a track only car I have a Varta Gel battery that loses nearly no content even in very hot conditions. Varta (a division of Johnson Controls) says they are absolutely maintainance free.
When I swapped the cars in spring I just sat in the NSX and started the car - the dealer couldn't believe it. He said he never had any ABS equipped car that stood for so long and started just like that (maybe ABS needs some mA in standby mode - don't know).
As the car is now a track only car I have a Varta Gel battery that loses nearly no content even in very hot conditions. Varta (a division of Johnson Controls) says they are absolutely maintainance free.