Home Alone

The HV battery will be fine for up to about 6 months...that won't be an issue for you.

The 12v battery may or may not be an issue. I suspect for just 3 weeks, with no SKS, if you're sure to turn off the head lights switch and all accessories/interior lights that it'll be fine too.

If you're particularly concerned about it just put the 12v on a float charger while you're away.

 

<div class='quotetop'>QUOTE(Oxo @ Sep 22 2007, 01:59 PM) [snapback]516247[/snapback]</div>

It's probably fine to do that, but it's not what I would do for a few reasons.
While the ICE will run for a minute, it'll then shut off. The 12v will charge directly from the HV battery during that time. But while the car sits during that 10 minutes charging the 12v it will be discharging the HV battery. Now, it probably won't do any harm since when the SOC of the HV gets to around 45% the ICE will come on, it just seems an unnecessary thing to do.

You didn't say how long you'd be gone...if it's a period of a couple months then I'd have your friend start and drive the car for about 20-30 minutes once every 2 weeks or so. This will keep the HV SOC high and the 12v charged.

If you're just going to be gone for a few weeks or even up to 2 months then it will be easier and better to just put the 12v on a float charger (cost you around US$20). Then your friend doesn't have to do anything and you don't have to worry about them not shutting it down properly or something.

 

<div class='quotetop'>QUOTE(prius2go @ Sep 22 2007, 02:11 PM) [snapback]516252[/snapback]</div>

Yikes! Please don't do this. What an unbelievable and unncessary waste of fuel and despite the very low emissions you're still just creating pollution unnecessarily. Further, once you do run out of gas the car will stay on until the HV battery drains to a deep level of discharge. While it will shut off eventually on its own you may have issues restarting, you'll find a car out of gas when you get home, and the long term impact of such a deep discharge is likely to be very bad for the battery.

For goodness sake just buy and use a little float charger and save that gas for another day.

 

<div class='quotetop'>QUOTE(prius2go @ Sep 22 2007, 02:19 PM) [snapback]516258[/snapback]</div>

Oh God, thank goodness...ya need a smilely or something in there.
I believe some of the police departments have managed to rig a larger 12v battery, the problem is finding one you can vent outside the cabin, and obviously finding a way to secure it since it won't fit in the slot designed for the 12v that's in there now. IMO way to much trouble to bother unless you absolutely need the extra capacity. I'd rather either disconnect the 12v if attaching a float charger is not possible or practical (ie if you have to park on the street) or use the float charger when practical.


You can also pull the DOME fuse for the same affect as disconnecting the 12v but it's much easier to do.

 

<div class='quotetop'>QUOTE(Albertus @ Sep 22 2007, 04:01 PM) [snapback]516295[/snapback]</div>

And I think that's completely reasonable. The only "But" I'll give you is that those folks who've had their 12v deeply drain often feel, probably b/c it's real, that their 12v never behaved the same again once deeply discharged like that.

So, I'm not really 'trying' to talk you out of your plan, I honestly think it's probably going to be fine. But it would be preferable to put it on a float charger for both the short and long-term benefit of your battery.

 

<div class='quotetop'>QUOTE(Oxo @ Sep 23 2007, 01:13 PM) [snapback]516559[/snapback]</div>

It's very easy to do from under the hood, no need exagerate the complexity. And presumably he's bright enough to have thought through as far as realizing he'd need a power source to jump from.