New prius Prime with dead 12v battery this morning

It could be a defective battery. That is why there is a warranty. I believe there was one other Prime here that needed a battery too.

 

Yes. That is what your warranty is for.

IIRC, the 12 V should be charging slightly any time it is plugged in.

But something is definitely amiss. You would have to leave a large current device turned on to draw down the battery if the charging was working.

 

Check the car's build date, on the decal in driver's door threshold? Maybe it's been sitting on dealership lot for months? I kind of doubt it with the Prime though.

I'm guessing the battery took some abuse at dealership, maybe door's left open for multiple hours during dealer prep, and/or the workers running the radio in accessory mode, something like that. Phone them up, see what they can do, considering how new it is.

Hey: when you showed up to take delivery, did they have it running...

 

since you plugged it in, but it didn't charge, i have to assume you did something wrong. do you use the timer function, or charge right away?
not sure if gen 4 shuts out all the lights if you mistakenly leave them on, but i thought so. dome light has always been the 12v killer on previous gen's.

 

maybe nothing, hard to say. i'm thinking you left a door ajar or something. but if it is a defect, you don't have to go back to the seller, you can take it to any toyota dealer.
remember, you have a free tow with toyotacare.

 

generally, when the timer charge doesn't start, it is a user error, but i can't speak to your specific instance.
they have probably increased the door casketing to reduce wind noise.

 

If the door didn't fully close, wouldn't there be a visible warning about a door being ajar? The Camry shows the graphic for that even when the car is off. It is possible the car simply won't charge if a door is seen as open.

Wasn't there warnings that the 12volt could discharge if the car is plugged in for too long?

My father had a defective battery in a new car, so that is entirely possible.

Toyotacare will only tow you to a Toyota dealer.

 

I've just experienced nearly the same.

My Prime had a full charge two weeks ago. I heard the half din of the aftermarket alarm, and, after stopping the alarm, all went dark. The plug-in would not initiate the charge, so AAA got it jumped in a second. But, again, the plug-in would not charge. I then tried my 3A battery tender but presumably the battery's voltage was below 3V and could not initiate the trickle charge. A second AAA jump, a few-hour joy ride later (without risking turning off during), and the plug-in began charging as normal. As well, after the hybrid battery was fully charged, the battery tender charged for less than a half-hour before going green. All's normal, now.

I'm sure that the only possible discharge is from the alarm, but to deplete the hybrid and 12V battery in two weeks is inconceivable.
I thought that at least I could begin the plug-in charge but, evidently, it requires nominal juice to detect and proceed-to-charge??
What gives?

Seems a 400A portable jump starter is a nice-to-have when in a pinch.

 

Sounds like your alarm is draining the battery somehow?

Try your battery tender again? Is that the brand name?

 

any news?

 

I'm pretty sure the lights only time out when the switch is in Auto. Should be a simple check in the owner's manual. I came upon a Gen 4 with the lights still on in a parking lot once, and the switch was in On, not Auto. So, that makes me think it is so.

 

I guess the alarm is drawing some battery but I can't imagine it discharging both batteries in two weeks time. I've had the car since July and, since it's still a backup to my 2004 Prius, it sits in the garage for weeks at a time. Regardless, my discovery is that you can't plug-in charge your depleted hybrid battery if your 12V battery is depleted.

 

It won't. You are operating under a mis-conception here.

Unless there is a really strange failure at work, NOTHING will discharge the HV battery when the car is OFF.
But many things can discharge the 12 V battery......including the battery itself when it gets old......and without a working 12 V, they system cannot determine the condition of the HV side.

An active after-market alarm can definitely drain the 12 V down below a usable level in two weeks; sometimes within a few days.

 

On the Gen 4 withhout Auto, the default timeout is 30 seconds, IIRC. I changed mine to turn off immediately. This is documented in the owners manual.