There are many smart chagring systems out there to keep the 12v battery charged, invest in one. Turn off the smart system, if it has one, and you should be fine.
The high volatege battery is covered by the 8-year/100,000-mile factory warranty. I have never heard of warnings that the high voltage battery will die. Over the years, when sales were slower, we have had Prius vehicles sit unmoved for 2 to 3 months. if we forgot to turn the smart system off, we just had to jump the 12v battery and off we went. Never caused a problem with the high voltage battery, it was low but worked fine right away.
Last edited by isaiah58; 05-14-2008 at 06:33 PM.