2010 Prius Dead Battery - Left Stranded!

It had happened to some French owners too.
I think that the batteries will be replaced under guarantee.
Will you I give a glance at it on the french forum ?

 

Perhaps they could check the physical connections between the battery terminals and connectors. In my Honda, my positive terminal wasnt completely secured. So it wouldnt fully charge the battery from the alternator and eventually just drained the battery and died. A jump start and a wrench to tighten the connector and all was back to normal.

It is hard to diagnose, since the battery holds a charge when charged, the alternator is putting out the correct charging voltage, and the terminals have the correct voltage, it is just not getting to the battery. Almost impossible to detect.

 

Do you ever sit and wait for the kids with the car on? If you do, in either accessory-mode or neutral, you've deep-discharged the 12-volt... and consequently damaged it.

Intentionally preventing the engine from running like that drains the 12-volt without giving it an opportunity to recharge.
.

 

John, what do you mean? I've sat and listened to my car radio on other cars for thirty minutes or more without a problem -- why is Prius different? I'm not challenging you, I know this car is different, but I don't understand what I'm supposed to avoid.

 

Most cars use the 12v battery to turn the starter, so they have a relatively large 12 battery. The Prius starts the ICE with MG1 getting electricity from the HV battery, so the 12v battery is relatively small.

If I was going to run accessories for more than five minutes, I would do so in Ready mode, so the 12v battery is not discharged. It is vital to start the computers, so they can start the ICE.

(If, like me, you turned on the lights at the dealer and never turn them off, this is especially important. The headlights do not turn off when you turn off the car, but when you open a door, so you can unknowingly run 150 watts of lights when you meant to run the radio)

 

Did you ask for the battery voltages from the dealer? Put the car in Maintenance Mode & see the voltages for yourself. Please tell us what they are.

Since I believe the battery is weak I suggest hooking up a trickle charger & checking the voltages regularly. Dealing with a weak or dead 12v battery is a PITA.

For a 5 minute stop I don't power down the car. I just turn the radio, fan & lights off then manually lock the door.

I am presuming that when 12v power is lost Safety Connect doesn't work.

 

The purpose of the 12-volt battery is quite different than with a traditional vehicle. It doesn't even start the engine. So, there's really no basis of comparison available. Just always leave the system started as normal and you'll be fine.

In other words, leave it powered up and in PARK when you are stopped and listening to the radio. That way, the engine can come on from time to time to maintain the 12-volt.

Switching to neutral or accessory mode prevents normal up keep.
.

 

To be redundant, as John has said, the operative word here is PARK.
I killed the battery three times, once unknowingly, once accidently and the window film guy killed it the last time.
All because the ignition was ON but the car was NOT in PARK.

Now I ensure the PARK light is ON before I leave the car (or else the car screams at me..beep...beep...beep...yeah, yeah I know...)

You can remove the little 12v battery and head to the auto parts store and get it checked if you are worried. Otherwise, just throw a charge on it. (Yes, you can safely charge the little battery while it's in the car, just follow the owner's manual instructions) Been there, done that.

Oh...did I mention the word PARK yet?


Sincerely,

ZC1

 

I'm buying a small battery charger with a float voltage maintenence mode and permanently installing it in the car.

 

The key here is that the Prius uses a very small 12V battery. Since it doesn't do any of the actual cranking, there isn't much need for a big 12V battery, which would take up space and add weight. The downside is that you can kill it pretty fast.

Tom