Storing a Prius a few weeks

You should be fine, it is the 12 V. battery that gives people the most problem.

Some good info here.

BU-702: How to Store Batteries – Battery University

 

There's a very high chance the HV battery from 2007 will be unbalanced and will fail when you return.

 

If you're extremely concerned about the Hybrid battery running low you can manually charge it all the way up before going on your trip. The 12-volt battery is easy enough to disconnect from a car, or put a battery tender on it.
To fully charge the Hybrid battery start the car up I would suggest driving it around first so that everything is warmed up. Go back to your house leave the car in Drive keep your foot on the brake hard and floor the gas pedal and you can charge the battery all the way up the engine will run fast for a while and as the battery charge increases the engine speed will decrease as the charge level increases. You can look at the information screen and see the battery level going higher eventually the car will stop putting power into the battery. I would suggest at that point putting the car in park and letting it sit for a little bit you may find that the gasoline engine runs for a while stops and starts several times I believe this is to get the temperature down on the hybrid cooling system but I'm not sure. Every time I have done this the engine starts and stops a few times after I complete the charging.
Honestly if the battery is in the blue section you should be perfectly fine. When I bought my car it had sat unused for months, and fired right up.
but it's useful to know how to fully charge the Hybrid battery if you want to.


Posted via the PriusChat mobile app.

 

My 2005 with 550,000 has had fewer days off than I have. My Mothers 2005 sits for weeks in the garage and has only required a jump once after leaving her dome light on for days. Her batteries last just as long as mine. As a carpenter I've learned from my cordless tools its best not to let fully charged batteries get hot, or to charge a hot battery.
The Prius engineers by the GEN 2 had found just about every current leak in the Pri and solved it. I would let it sit for three weeks and test for 12 volts. Only when it dropped below 12 Volts would I put a trickle charger on it. Why you say? Lead Acid batteries, your 12 volt battery, work by stripping electrons off of lead plates with Hydo cloric acid. This acid, as it warms, off gasses hydrogen. This is why the battery has a vent that goes outside of the car, as the gas is quite combustible. as the hydrogen evaporates the acid becomes more and more dilute. Just ask anyone who sells batteries how often they put a trickle charger on their new batteries in the store, they don't. Your attempt to do a good thing for your car would actually age it.
As to the storage of a high voltage battery as long as it has a couple bars it stores just fine no attention needed for months.

 

how many miles on her?

 

there is some risk that a 12 year old hybrid battery commits hari kari from not being used regularly. can't put a number on it though, or why some do and some don't

 

I'm kinda sceptical that a week or two downtime is tough on the hybrid battery. The 12 volt yeah, but I believe the hybrid battery is effectively isolated, no drains, when the car's off?

Our car sat new at dealership for over a year, and nowadays 2~3 days without use is often happening, and it seems the same as day one. I'm thinking relentless hill-climbs might be more of a factor, day after day.

I found this:

How long can a hybrid sit unused in the garage? - The Globe and Mail

And there's something in the Owner's Manual I recall, which seems pretty lenient:



(page 30 in my 2010 North American Owner's Manual)

 

the computers help balance the pack when you're driving. if any cells are on edge, maybe they slip into no mans land when sitting and cannot recover without help. no idea, just a wag.
we do know (i think. i don't know anything for sure) that older low mile packs don't seem to do as well as higher mile, hence the prolong solution

 

which brings me to my daughters 2008 with 130k sitting at the gas station all winter for sale.

 

A Prius sitting at a gas station all winter, they probably think there is something wrong with it.

 

Perhaps it’s time to lower the price?

 

Maybe older, more unbalanced packs are more vulnerable. Sounds like me...