2010 II 12 Volt Battery Dead After 17 Days of Parking

Ahh! that's a very good question because.. the hatch doesn't have a mechanical lock on it does it? I guess you could fold down the back seats before you store the car and disconnect the neg. terminal on the battery so you wouldn't have to climb over the seats.

 

That's ridiculous. Not you, what your dealer told you. If it is true that we should expect the battery to go dead after sitting for a couple weeks, which I doubt, then the battery is seriously undersized for the job and I will be greatly disappointed in Toyota. We should not have to disconnect the battery and lose all our radio presets and whatnot just to leave the car in airport parking for a couple weeks... who ever heard of such a thing! Sheesh, makes me long for a crank on the front. Heck, for the power it takes to engage a contactor and boot up the computer, you ought to be able to jump the thing from the USB port on your laptop.

 

Wouldn't you just use the key? ....oh I see what you're saying; I'll have to crawl over the seats and all. Eh, no problem.

And yes, this does seem to be a hassle on a brand new car but I suppose that's the state of the art with the available technology at this price point.

radio

 

The fob? If the battery's dead, the fob wouldn't work to unlock anything.

I don't think there's a slot on the back for the little mechanical key.

 

get a solar 12V trickle charger and park on the top floor.works great.

 

All the more reason to think about hacking the solar panel... let it run the fan when the battery is charged and switch over to trickle charging the 12V battery if it gets low.

 

F'krissake, can't someone just go out and MEASURE the quiescent
current and report back??
.
It would be nice if there was a way to tell the car, "disable
SKS and RKE *now*" for just such occasions. Maybe the relevant
ECU harnesses could be pulled behind the glovebox. But instead
of waiting 5 days, someone should see if the "disable after key
is within range for 10 minutes" actually works, and how long
it remains in effect if/after the key is removed from the field.
.
_H*

 

Yo Rachaelseven! I bet you have a clamp on Amp meter? How about doing what Hobbit suggested and measure the current with the car off, doors closed, etc.

I'm still 1500 miles from home in a motel and I don't have a meter with me.

 

If the car can still be started whith the "short pin" removed it can't unhook the 12V battery. So I wonder what it does?

 

I do, actually. If I can steal a few minutes away from work tomorrow, I'll go out and check it. But refresh my memory... I'm a mechanical chick, not electrical... do clamp on Amp meters work on DC? I thought they were AC only... something changing current and induction and all that good jazz?

 

Some do, some don't. The more expensive ones will work for DC.

 

Good question, as sciguy125 said some do some don't. The ones that measure DC use a Hall effect sensor and tend to be rather spendy such as this one: Amprobe LH41A Clamp-On Ammeter Digital AC/DC Amprobe LH41A LH 41A LH-41A

You may not have access to one but I think there is another way, all we need is a guinea pig.

With all the stuff shut off, i.e. interior lights, etc. it should be possible to power the car with 12V through the jumper cable connection or even one of the power outlets. Then one of the 12V battery cables could be disconnected and an inline Amp meter installed. Then remove the temp source read the current and reverse the procedure to remove the inline meter. Or maybe better yet just put the meter in series with the temp source and unhook the 12V battery long enough to get a quick reading.

The alternative would be just to unhook the 12V battery and lose all the radio settings etc. I wouldn't mind that but I'm not sure if the backup beeper to 1 beep and the seat belt beeper to off settings would be lost as well? Anybody know?

 

One significant difference is that the cars have just completed a long journey via ship, rail and truck without any use. They've probably been on only long enough to move the cars onto/off each transport vehicle -- not long enough to provide an opportunity for much charge to go back to the auxilliary battery.

This also is one of the reasons for a warning against replacing the battery with some other type -- so the dealers don't just put new but wrong batteries in the cars.

 

I believe this is one of the reasons for the TSB suggestion that the disconnection should be of the harness in the "jump start" setup under the hood.

 

Sounds like that "short pin" is the SKS disable switch.

 

More than one computer has to boot, and they're not exactly designed for low power. Hobbit reported 300-400W with all the computers on, on the Gen 2. That's 25-35 amps. I believe Toyota have reduced the number of computers a bit on Gen 3, but not substantially.

As for the main relays, the more current carrying capacity and operating voltage required, the larger the contacts need to be and the further apart they need to be to get a large enough distance to prevent an arc. That requires more effort and hence bigger, more powerful coils to get them to switch over. More effort and bigger coils, more current required to energize the coil and activate the relay.

You're not going to manage any of that from your laptop, where the USB spec is 5 volts at a maximum of 500mA. Many computers can't even manage that rating - USB devices must declare to the computer what power they require and should support configurations where the computer supplies much less than this.

The question no-one has yet asked the OP is, do you have the alarm fitted? Alarms use substantially more power when the car is 'off' than most other accessories.

Since the car is very new, I wonder if the dealer actually did what they were supposed to (as given in that TSB) and made the car READY for half an hour immediately on receiving it, to let it recover from the trip across the Pacific. If the 12V was already pretty weak, you might not have got that much life out of it.

 

True enough, and I apologize for the poorly conveyed sarcasm of my USB remark. Yes, clearly you could not actually start the car with the amount of power available on the USB bus - I was trying to be a bit tongue in cheek - but I do think there is actually probably enough power in the laptop battery were it suitably connected.

Anyway, those devices with little internal batteries that allow you to self jump are looking better and better... something like this:

Viatek Vp01 : Volt Security Starters / Mobile Audio Video Accessories

I'm thinking the flashlight in the tray under my trunk floor needs to be replaced with one of them in case I ever have to leave the car parked long term.

 

I'm not certain this jump-starter will work for the Prius without making a change to the electrical system. The 12v plugs in the Prius are not in an always on mode. They are connected only when the Prius is switched to Accessory or On ("Ready") mode.

I'm far from being the electrical expert, but I don't think you can get the Prius into Accessory mode (and definitely not into On) when the 12v battery is dead. This prevents you from getting the connection necessary for the jump to work when it relies on the 12v plug for making that connection.

 

Some additional info:

Because the Prius is not meant to be used to jump start another car (see page 546 of the Owner's Manual), I thought I would get a self-contained battery-operated unit and started a thread on the subject (Jump You: Jumping a Non-Prius with a Portable Starter).

Rokeby made an early and valuable contribution to the discussion. See his post in that thread. He found a small portable starter that would use the 12v plugs in a car to slowly recharge the battery. Because the 12v plugs are not always hot, he devised a way to change that for one of the plugs. (As far as I know, the Gen3 and the Gen2 have similar settings.)

If you read through the rest of the "Jump You" thread, you'll find other folks' options and suggestions, but if you are comfortable making the mod suggested by Rokeby (and are aware of the danger of having an always hot 12v plug in the Prius), then this could be just what you're looking for.