Hybrid battery drain?

The owner's manual of the Prius does talk to this.

The issue is that the small 12v battery which powers the computer could, with the normal power usage of the various systems of the car (even when the car is off some things are on and using power, like the smart key system, radio, etc.), drain when sitting too long.

If the 12v battery (nowhere near as large as the 12v battery in a non-hybrid car) drains, you'll have to charge it or jump it (or change it, I guess, for a new one) to get the computer to boot up and allow the system to run.

Without that small 12v battery, all the juice that's in the powertrain battery is useless.

The owner's manual says to run and drive the car a few minutes every now and then if you're going to just let it sit for quite awhile.

You can leave it on a trickle charger, too. Or simply charge it up when you come back to the car after a couple of months.

The dealership guy was right, but he exaggerated the issue.

 

<div class='quotetop'>QUOTE(Clay Suttner @ Mar 31 2007, 11:25 PM) [snapback]415764[/snapback]</div>

Clay,

There is no risk of draining the hybrid (main) battery with lack of use. The main battery is completely disconnected when the car is off and they will drain slowly so 6 months of no use could be a problem, but not 3 weeks.

The other factor is the small 12v battery that is needed only to initially start up the systems. It will drain in a few weeks due to the electronics that remain on when the car is off. There are two good solutions:

1. Disconnect the 12v battery when leaving the car alone for more than 1 or 2 weeks.
2. Get a "battery minder to maintain the 12v battery while you are away.

Tell your friend to enjoy the new car and not to believe everything the dealer says.

JeffD

 

I would presume there's a push-button switch on the lexus rx400h. On the Prius it's below the steering wheel. Pushing it in turns it off.

OOPS, TP posted before I finished. No SKS, no disabling it.

I just took a look at the RX400h site and it only says: Remote Keyless Entry Multifunction in-key remote with rolling-code technology

 

Prius owners, your SKS shuts itself off after one week of inactivity. You'll have to manually turn it back on again with the switch.

Even though I have a base model without SKS, I remember this from--drum roll, please--reading the owner's manual.

 

Instead of starting another thread on battery drainage, I'll add my question to this one. I'm going to be away for about three months. For fiscal reasons, my car will be stored in a car storage warehouse and will not be allowed on the road while I'm gone, this will save me a lot of €€. The storage warehouse offers a service where they can start the car for me every so many weeks. But they will probably not move the car at all, certainly not if it happens to be stored in one of the compartments that can only be reached by a lift. I have the SKS.

How can I best prevent the 12V and traction batteries from draining? Is 3 months an issue for the traction battery? What instructions should I give the storage company?

 

The traction battery shouldn't drain. If they simply start the car like you would, and let it sit there for 15 minutes or so in Park, that's all you need to do.

The traction battery will charge up the 12v battery, and the engine will run as needed to keep the traction battery in the range it needs to be.

The owner's manual covers this situation in nice detail.

 

Sorry, it's 14 days, not 7 days.

07 owner's manual, page 33, middle column, "BATTERY POWER SAVING":

So it looks like if you're standing outside your car jaw-jacking with your friends for more than 10 minutes, the SKS will shut off. You'll have to press the lock button on the outside door handle or use the remote or use the mechanical key.

I wonder how many people are now saying, "AH-HA!"

 

<div class='quotetop'>QUOTE(adam1991 @ Apr 1 2007, 11:44 AM) [snapback]415942[/snapback]</div>

This is also true with the 2006. Same page in the manual.

Tom

 

<div class='quotetop'>QUOTE(Tideland Prius @ Apr 1 2007, 07:49 PM) [snapback]416170[/snapback]</div>

Could that be a Canada-only thing for 04/05?

Evan? What's your manual say?

 

<div class='quotetop'>QUOTE(lowlander @ Apr 1 2007, 07:30 AM) [snapback]415899[/snapback]</div>

It's probably OK if you do nothing (and have them do nothing). However, if you want to be safe, I'd disable the SKS (push button under the steering wheel). Actually, I'd do this for two reasons: (1) You can be sure that the SKS won't cause a battery drain and (2) you can be sure that if the "car storage" people move the car around, they have to put the fob in the slot to move it. Why do I think this is important? Because this means that it is impossible for anyone driving the car to walk away with the fob and have the car still running. This way, you'll ensure that you car isn't running in its spot for the 3 months you're away

I would also make sure that you don't have anything plugged into the cigarette lighters, as that can cause a drain on the battery. As far as the main traction battery, I think you have nothing to worry about; I'd just let it be and tell them not to do anything to your car while you're away.