Newbie with questions

The 12v battery should have been the one to be drained in your scenario.

Have you ever replaced your 12v battery? Have you checked it to see the voltage recently? I suspect you're nearing the need to replace your battery due to age and leaving the dome light on for 10 hours drained it enough for the car to act wonky due to low 12v battery voltage. Putting a charger on the 12v battery probably got it back to an acceptable voltage level so the car ran fine after that.

About your least question about the car being able to run on engine only, I'm thinking no. I think the traction battery has to provide some assistance for the car to move, it can't be completely and utterly dead. If you look at the hybrid transaxle, even though the engine is connected to the wheels, it has to go though a planetary gear setup (that also involves the MG1 and MG2), so without power from the traction battery (even a questionable traction battery) the engine itself can't move the car. At least this is my understanding.

If I were you, I'd plan on replacing your 12v battery soon if you haven't done so already. Research on how to check the 12v battery's voltage to see what state it's in. You might be able to get away with a few more months before replacing it, provided you don't kill it by leaving the dome light on...

Scott

 

Hi The Dealer battery is about $135 plus labor

Optima sells a Prius 12 volt battery, the only safe aftermarket battery in the US:
Optima DS46B24R Optima battery direct fit replacement for Prius 2004 +

 

What is wrong with the Exide Edge battery FP-AGM51JIS exact fit for the Prius correct posts,and vent tube. Higher amp/hr capacity than the optima with 4year full replacement guarantee at comparable price. Available in the US.

 

First I have heard of it, so far I have found no US websites who will ship it, but it would be fine if they did.
http://www.exide.com/Media/files/Downloads/TransAmer/Products/Edge%204%20page%20booklet%20non%20spread.pdf
makes it look like it was introduced 1/2012
'Retail' Locations near me selling Exide batteries have names like Peterbuilt of Memphis and MidSouth Kenworth, they will be amused to get a Prius owner looking for a battery.

 

The OP did replace the 12v when he got home. I am wondering if all is well since the 12v change? H

 

The 12 volt battery runs the computers, once they are not getting a good 12 volts, they will be erratic. Do not hesitate to replace the 12 volt battery if this persists.

 

Did the MFD (touchscreen) indicate the traction battery was low (0-2) bars? Or did you just see the big red triangle and some other dash lights?

If the MFD incidated a low charge on the traction battery that maybe just be coincidence. Perhaps it was low when you parked the car (from climbing a hill or running the AC) then the low voltage on the 12v battery caused the hybrid system not to charge it when you were driving after draining the battery. This is speculation on my part...

There are relays between the traction battery and the hybrid system so when the car is turned off, no power can flow to or from the traction battery. So leaving the dome light on can only affect the 12v battery.

I'd keep an eye on everything. If you notice any other weirdness, have the dealer look at it.

Scott

 

Theory 1) 12 volt battery is so low it can't activate relay, so HV battery never comes online.
Theory 2) 12 volt battery is so low that the computers do not produce accurate results.

 

Sears are advertising this battery for delivery to the UK from the US for a nominal delivery charge of £20 add cost of battery at £95=£115. That is over £70 cheaper than the Optima in the UK.

The battery is also available "according to there adds" at Battery Service Corporation Chicago, next day free delivery.

Side by side Sports.com (nation wide).

Cooper State battery, Pheonix and Las Vegas.

In the UK and Europe it is against the "sale of goods act" to advertise something you cannot supply or do not have, do you have an equivalent legislation in the US.