Car going to be dormant for 52 days

A boat battery is usually much different than a car battery.
Actually, you'll often see a whole classification of "marine" batteries if you go into a large battery section on my local battery store.

 

Dormancy test data:

1. Previously drained battery on a brand new 2014 Prius - jump started back to life by Toyota Care
2. Left dormant for 17 days + in temperatures ranging from a low of 30F - 70 F last & this month. Car alarm blinker in dash is on
3. 17 days later - the car starts, no worries.

If I had to leave it dormant & unattended for longer periods of time - I would probably disconnect the tiny battery. And it is a little guy for sure compared to other car, boat or underwater scooter batteries I have dealt with.

 

I'll be gone for about 12 days, should be ok

 

I guess I can't totally argue with that but it really is better to connect a "tender" type battery charger, if you can do that easily.

It is better for the battery AND better for you so that you don't notice that the car is running "funny" after you reconnect the battery and all of the computer's memory is lost.

 

This is very interesting. My Prius battery was dead for a week, or too low a voltage to turn over the ICE. No data was lost to the best of my knowledge….but it only had about 100 mph!!! That said - what systems would be affected and what types of data are backed up should something like the battery go totally kaput?

Cheers,

Cape Ann

 

On other cars I'm familiar with, the battery maintains the computer memory that has learned from the sensors over time and has stored the learned values to use as normal to factor into the computation it uses to maintain the air/fuel ratio. Replacing the battery and you have to go through several driving start drive stop cycles before the values are relearned. I've also seen the radio presets and even auto seat and window options and the like lost. Use a maintainer on that car and no loss of any of the above.

Not sure what is connected to the 12v on the v.

 

What he said ^^^^^

 

If you are going to be leaving the car dormant for many months I would just disconnect the 12V battery and put that on a CTEK charger (I use the CTEK 3300 for mine on long trips as it won't ever overcharge the battery). Then pull the orange safety plug on the hybrid battery and that will isolate the traction battery from any exterior current drains and the modules themselves (if in good condition) will lose voltage very, very slowly (may last a year or more this way). Then when you get back just reverse the process (plug first, then connect 12V again). If you are gone for less than 3 months just hooking up a trickle charger (as mentioned above) will work fine.

 

We have left ours for 60 days ...no problem at all, 12 volt was still up and hybrid bat didn't look like it changed on the dash.
On our Sienna we used a type of battery tender, (harbor freight $4.95 special) for 6 months and no problem when we went to start the van.

 

It is NOT necessary to disconnect the battery to put it on an automatic charger.
And the charger should be an automatic tender type.......NOT a super cheap trickle charger; those can over-charge over long periods of use.

 

Your boat has a pretty big battery, and it's probably all the way disconnected when the hull is dry.
The OP is letting the car sit idle for 7 weeks.
It will probably have zero real-world impact on traction battery.
The aux (12v) battery is a far different story since as mentioned above there are constant draws on this battery and Toyota used a painfully inadequate battery.

My employer uses Priuses as fleet vehicle and we do have problems with cars not starting properly after sitting idle for >2-weeks.
The last time this happened with mine(4 months ago,) I jump started the car and got on with my life.
The time beofre that?
The battery went Tango-uniform.
Your call.

I have 2-$20 WallMart battery maintainers that I rotate between 2 motorcycles, a ZTR mower, and 3 cars.
I've got 15 years of experience with these and for my applications they're jsut as effective as the gollywog $100 units.
The only reason I don't use them on the Prius is that I don't home garage.

This is one of those "6" versus "half dozen" things.
Me?
I'd get and use a battery tender.

Goof Luck!

 

I never said it was required at all (I always leave the 12V on a tender and still connected while on shorter vacations) ........the CTEK is a smart charger too BTW. For longer term storage (several months) I would probably just pull the hybrid service plug and leave the 12V connected (disconnection of 12V is more for corrosion problems) but no big deal if you have sprayed the terminals.

 

If you have an AGM battery like the car came with, it is sealed and there should not BE a corrosion problem to begin with.

But I still like a little something on the posts anyway.

 

So my car sits there seeking out if my key fob is in the area. Any data on how long it will do that and what the drain is on the battery? Modern cars with all their smarts aren't like the Model A where off meant just that.

(For a previous car, I managed to get a chart showing how many amps each feature/option drew after shutdown and for how long. My practice was I used a maintainer if I planned more than 2 weeks without use. Since it was a sports car and I had a 4WD for winter use, it sometimes sat for weeks. And the battery never let me down. Only reason I replaced it after ~7 years was caution. Plus I wanted an AGM.)

 

X2

Completely agree.

 

I don't have the manual right in front of me, but it indicates that after about 10 days it stops trying to seek out key fobs.

 

It may be fine this time since the battery is relatively new. But if this were and older pack, this would not have been good.
A High Voltage charger/balancer would help keep it healthy.