I'm new to this forum and hoping that I can get some advice. I am storing my 2012 Prius V for several months, and have been adviced to hook up a battery maintainer. I have two questions: 1) is it better to leave the battery connected to the car, or take it out of the car, and 2) if I leave it connected, what amperage maintainer (12V) should I use to maintain the car's electronics. Thanks much in advance. Dennis
The Owners Manual* recommends to remove battery before charging, and keep the amperage under 4~5 amps (forget which, roughly that). FWIW our 2010 is near-constantly on a charge, battery in the car and fully connected. I’m using a CTEK 4.3 (4.3 amp) smart charger. Its current equivalent is CTEK 5 (still 4.3 amp). These chargers can be safely left on indefinitely. we’re very low usage (under 5k kms yearly, on our 2010 hatchback), most recent battery replacement was September 2015. I’ve followed aforementioned practice since install, and battery still testing like new. * If owners manual missing pdf versions available on Toyota Tech Info website (just Google that name).
We also use a CTEK 4.3 on the ‘fleet’, each with charger state telltales. No issues, whether wet or dry cells.
