Going on a 3 month trip, how to avoid a dead 12v battery?

I disconnect the negative battery cable from the 12 volt battery. You will loose your radio presets so write them down before disconnecting the battery. My car is in a garage so I put a work glove over the hatch latch so I can open it when I return and reconnect the battery. This has worked well for me. I also make sure to drive the car before disconnecting the batter to make sure the traction battery is charged. Hope this helps.

 

Not enough, disconnect the 12v (see above) or attach a "Battery Minder"

Just press the door unlock button (if the 12v is now connected) on the remote.

Yes

If you disconnected the 12v, you will have to reset the radio settings and reinitialize the automatic driver side window opening by fully openning and closing it.

JeffD

 

Or (just a thought) you could install a new Optima before you go, turn off SKS, and just have a nice trip.

 

Drive?

 

Ask a trusted friend to drive it every couple of weeks. I left mine last Winter for 6 weeks; a friend drove it once after 3 weeks and it was strong a ready to go when I returned.

 

What is SKS? sorry i'm new to Prius..
and how do you turn it off/on ??

 

Smart Key System

Its the system that senses key fob proximity. It uses power
when the car is powered off. Although minimal current draw sometimes on prolonged absence it will kill a borderline aux battery. Although, many reports of people going away for 3 months and coming back with no issues but its best to be safe.

To turn the SKS off there's a button under the steering wheel.

The major determining factor is if you have ever had to jumpstart your battery just once its not a good candidate for prolonged absence even with the SKS off.

 

Come on people! RTFM! The SKS system will turn off by itself after a few days of no use. It is -UNNECESSARY- to turn it off manually.

For three months, I'd disconnect the battery -ve terminal unless you have a battery tender to leave connected to it. The Prius 12V battery, even when new and/or in good shape is only going to hold enough charge for about 4-5 weeks of no use, SKS or not! This is not only applicable to the Prius as well. Most modern cars will drain the battery over this kind of time interval of no use.

You WILL have to figure out how you're going to get into the hatch to reconnect the battery. I recommend connecting another 12V source to the boost terminal under the hood to energize the hatch release. A portable boost device is a good choice here, as you can leave it plugged in in your apartment, but even if the car is left at an airport a portable boost device, left on the floor of the car while you are away, should be able to power up the hatch release when connected to the boost terminal.

 

Every winter our 2008 prius goes into garage storage for three (3) months. 1st, we change insurance coverage to comprehensive only; $$$ savings. 2nd, disconnect the cable from from the battery (10 mm wrench) located on the right side of the trunk. Leave the wrench & work lite close to the work site for ease of reconnection. 3rd, check & clean the cable & terminal connections. 4th, use something to insullate/ separate the terminal & cable from each other. Before closing the hatch I put a shop rag over the lock latch. The key fob then goes into a security container.