I put my NSX in winter storage on Nov 15th, 2017. I connected the OEM charger (CTEK) every two weeks to top up the 12 V battery. I started my NSX today after 2 1/2 months of sitting. The EV battery was at about 85% so hadn’t lost much in 2 1/2 months. The car started instantly and ran smoothly. Put it in Sport Plus and the EV battery was fully charged in about 5 minutes. I think once the EV battery is fully charged it will last 6 months. As usual Honda is being conservative recommending a 30 minute run every 90 days.
Submitted by Jim Cross