Disabling SKS drained battery?

Disabling SKS does not kill the 12V battery. You were trying to do all the right things, but it sounds as though something killed the 12V battery anyway.

Do you have any aftermarket electronics installed? They sometimes cause excessive drain.

Do you *always* lock the car? Always locking is an easy way to prevent many common battery-killing events.

[Oh crap, I overlooked "run for a couple of minutes". Yes, that will eventually kill it. In a cold climate it needs at least 20 minutes of "READY" once a week to keep the 12V battery charged.]

 

The problem is that you only let the car run "for a couple of minutes" at a time. That does not help to keep the battery charged. You must leave the car READY for at least 30 minutes, every two weeks. (Not necessary to actually drive the car as long as it is READY with the gear selector in P.)

Turning off SKS did not hurt your situation. However it did not help because the 12V auxiliary battery is close to being dead now.

If you do not charge the battery up in the very near future, then expect that when you finally get around to it, the battery will not hold a charge and will need to be replaced. (It may already be permanently dead.)

If you must store the Prius for an extended period, then it would be best to either disconnect the 12V auxiliary battery (once it has been fully charged) or else hook up a battery tender (if you have AC power nearby and can leave the tender plugged in.)

 

I think that several hours may be required to recharge the 12V auxiliary battery if it is near dead now. If you have access to a digital voltmeter then you can measure the voltage across the battery after leaving the car IG-OFF for an hour or more. 12.6V or better is considered fully-charged. When the car is READY you should measure 13.8V, which is due to the DC to DC converter providing higher voltage on the DC bus to power the Prius electronics and charge the battery.

To give you a data point to consider, I don't drive my HiHy very much and don't bother to use a battery tender, so the battery voltage is usually around 12.2V (which is considered around 50% state of charge.) I recently drove 500 miles one-way, and brought along a meter to keep an eye on the battery. After driving ~5 hours, I stopped for lunch. After lunch I measured the voltage and it was 12.4V. I measured the voltage again after arriving in the evening and letting time pass, and the battery was finally up to 12.6V. The voltage dropped back down the next morning, probably because of the very cold weather at my destination, lows around 10 degrees F.

 

IMO you don't need a jump, you need the battery charged. I'd hook it up to a charger & let it charge for a day or two. If it has been discharged too long then you'll have to buy a new battery.

 

It's pretty cold in upstate NY right now and batteries don't like cold, you may have to or want to bring it to the dealer for a total 12VDC aux battery check. Sometimes after total discharge, they are never the same. I think right now the tow is gratis because you are still under warranty. More trouble, but safer. If you jumper yourself, shut off the other cars engine, it's not needed. AND absolutely do not connect backwards!

 

OK, now I see why the car is being stored. No, the ICE will only run as needed to warm up, and this is unrelated to charging the 12V battery. In fact, Prius does not appear to monitor the state of charge of the 12V battery in any meaningful way.

I think that the purchase of a decent battery charger (and if needed, the necessary tools so that you can disconnect the negative battery cable while you are charging the battery) would be reasonable and help you to be self-sufficient in dealing with this problem.

 

I agree with Pats comments, however the dealer for good customer relations "might" drive you and the car back home. After that you could still have a problem it's really a great shame that this car isn't being driven. There are probably many responsible men or women that would love to take responsibility for the car AND act as your taxi-driver when you have to go some place. If you know of none go to the nearest charity or Salvation Army. You might make a new friend.

 

Before going too much further I suggest you read this.

http://techno-fandom.org/~hobbit/cars/prius-12V/

The entire site is extremely helpful. Understanding how the main battery supplies charge to the 12 volt battery is quite interesting. Primarily it is through the inverter while the ICE is running, but also through the inverter when the ICE is not running.

So, run the ICE. To start the system tape ten D cells together like in a flashlight. Use a couple of wires attached to the positive and negative ends of the stack and apply them to the points under the hood detailed in your manual for attaching a booster. If you are quick enough the computer will start and the problem of charging your 12 volt battery will be solved.

Even better would be borrowing a small booster, but D cells will work in a pinch for a low 12 volt battery. Not a dead one, just a low one.

There are times in all our lives when we must depend on the kindness of strangers. Don't be chary of asking for anything you need; you never know how good you can make anyone feel being helpful to you unless you ask them for help.

As for the dealer/driving problem, explain to the dealer your driving problem and he might allow two of the techs to return your car to your garage.

But much cheaper than towing is a cheap booster battery. I remember seeing a five and a nine dollar charger on sale at Walmart. One of those little motorcycle chargers would be fine for the Prius 12 volt battery.

Just don't get discouraged; look on the license problem as an adventure in alternate living.

 

It's easiest to jump and charge from under the hood. There is a jump point expressly for this purpose. It is clearly documented in your owner's manual.

You should be able to open the back doors if you insist. Manually unlock them from the inside.

Tom

 

The child locks may be enabled. In that case, you have to unlock the doors from the inside, then crawl out and unlatch them from the outside - it's a lot of bother.

You can jump from the battery, but you have to get there first. With a dead battery you can't open the hatch from the outside, so you have to crawl through, lift out the floorboards, lift out the tray, pop the cover, and pull the emergency hatch release. You really don't want to do that unless it's the only option.

The standard jump point is under the hood. Pop the hood and look for a black fuse box on the driver's side, close to the windshield washer bottle. Pop open the cover on the fuse box (it can be tricky the first time) and look in the upper left corner of the box (as you face back leaning in over the bumper). You will find a shiny metal pin sticking up inside the fuse box. This is the +12V jump point. Attach ground to the chassis or engine just as you would with any other car.

Tom

 

Pls note that 11.9V is very marginal. You would expect a new battery, fully charged, to be at around 12.6V after resting overnight.

Hence I suggest that you continue to make the car READY for a few more hours over the next few days, as your time permits, and see if the battery voltage comes back up.

If not, then expect that you will continue to need a jumpstart if you leave the car for more than a couple of days.

 

I'll second that.

 

i like this battery test via Elearnaid.com:

Prius battery test procedure for 2004 to 2009 Prius Cars
Here is a battery test you can perform on a Prius battery that is easy to do. It will not always detect a weak battery that does not allow you to park you car for long before it is drained down by the security system.

However, this test requires no tools, is easy to do and will give you some idea of the state of your battery. You can also perform this test after the car has been parked for a while to see how well the battery holds up under the drain from the security system.

• Do this test after you have driven the car for at least 30 minutes. This will give the battery a chance to be fully charged.
• Put the transmission in Park.
• Turn off the car.
• Engage the parking brake
• Push in the power button.
• Push Display button. top button to left of screen - "DISPLAY" will now appear in the upper left corner of your screen.)
• Push on the upper left(1) on the display just inside the box, withdraw, push on the lower left display(2) and withdraw . (see picture) Do this three times. Keep trying till the screen changes. If the word "Display" in the upper left hand corner of the screen goes away hit the display switch again.
  
• Push on Menu in upper right of display screen.
• Push on Display Check
• Push on Vehicle Signal Check
• You will see the 12 volt voltage displayed. In accessory mode the voltage should be 12.6
• With no electrical accessories on including lights the voltage should be fluctuate between 12.6 and 11.9. The lower the voltage, the less of a charge your battery currently has. If the voltage is low do not proceed as the load test might totally discharge your battery. (If you see a voltage around 13.8 you are seeing voltage from the high voltage battery being converted to around 13.8 in an attempt to recharge your battery. This normally does not occur till after you start the engine but might occur earlier if the battery is very drained.)
• You can also test the battery by turning on the headlights, rear window heater and the heater fan. For a new battery the voltage would be around 11.3. If the voltage drops below 10.2 it should definitely be replaced. For voltages in between the lower the voltage, the lower current charge of your battery.
• Note: If in doubt disconnect the 12 volt battery completely (start with the negative post to avoid shorting the battery) and hook it up to a battery tester.

12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008 and 2009 with free shipping