Dome Light Left On...Effect on Battery???

Sounds suprisingly good considering. Is the the original battery? If you can pick up a digital multimeter: the voltage on a healthy battery should be above 12.6.

Whenever I have an "incident", and just every so often, I hook up a charger with ours. This is what I'm using, though there are a lot of similar. The nice thing is it gives a rudimentary display of your battery's health. Well, really rudimentary: dead, so-so, or good. Read up on it: it's using several cycles, supposedly good for reviving borderline batteries.

Battery Chargers | CTEK Battery Chargers

Still, if it's the OEM '06 battery, might be time to replace...

 

Those bars are for the big traction battery, not the little 12V battery that gets run down by leaving lights on.

The 12V battery is more expensive than any previous car battery you have had (there are several threads here about non-Toyota options, particularly Yellow Top). But if is has never been replaced, it is already running on borrowed time even without this overnight error. Though the fact that is wasn't drained hints that it isn't the car's original 12V battery.

 

Sounds like your leaving the car in "Ready" instead of turning it off.

Tell me your NOT leaving it on all the time. !!!!!!!!

 

If the 12V battery was dead then the Prius would not start. That battery is required to power up the various ECUs before the Prius becomes READY.

I suggest that you ask your husband to charge up the 12V battery overnight, at 4A charging current or less. Then if you have no further problems, don't worry about it.

I assume that you are not the original owner of the Prius since you say you are a "fairly new owner" and you have listed the car as a 2006. If this is true then I am not sure your husband will know whether the 12V battery is original equipment or not unless he can find the date code which on the original equipment battery will be hidden under the battery bracket.

 

Each time you discharge a lead acid battery, it is weakened. Unless it is designed as a "Deep Discharge" battery (the OE Prius Battery is not), 3 or 4 times and the battery is toast.

They can last 5 years or more if treated well (kept charged and no deep discharges). Mine is still functional at 7+ years.

Typically 250k miles or more and 8-10 years, but some fail sooner. Mine failed at 194k miles and 7+ years.

The "Big" (HV, Traction, or 200volt) battery is about $3300 installed at a Toyota dealer. A $2000 option is to have a refurbished Traction battery installed (see: Remanufactured Hybrid Vehicle Battery Packs) or for about $1000 buy and install a salvaged battery. I had a ReInVolt refurbished one installed.

JeffD

 

The "traction battery" (the big one for which the meter on the dash displays the charge level) will last as long as you own the car, unless you are very unlucky. The car takes care of it better than any human could. Don't worry about it, just enjoy using the car.

The traction battery can stay in any charge state without damage. I don't think you could do anything to actually damage it, short of running out of fuel and continuing to drive until the car shuts down on its' own.
So just keep -some- fuel in the car (don't run out) or if you do run out of gas, don't drive the car until it stops on its' own.

The traction battery will last a very long time. There are taxis with over 300,000 km on them. If it does die yours is warranted until 2016, mileage limited I think to something like 100,000 mi. It would cost in the order of $4000 to replace with a new one if you managed to get out of warranty.
But it is considered by Toyota and the rest of us to be a lifetime part.
So as I said, just enjoy.

 

The traction battery costs ~$2,300, plus several hours of labor time to replace. There are alternatives to buying new, such as buying a used battery from a salvage yard (maybe $600 or so plus shipping), or buying a "remanufactured" battery for ~75% of the new price.

One bar on the traction battery state-of-charge gauge is OK, especially during the summer when you have heavy air conditioner usage. The AC compressor is electrically powered by the inverter. The inverter will take power from the traction battery while the gasoline engine is not running.

40 mpg for stop and go city traffic isn't bad, again assuming you are using the AC heavily in hot summer weather. I suggest that you take a long drive where you are moving at a relatively constant pace on level terrain and your average speed is around 50 mph or so, and see what mpg you can log.

The traction battery is supposed to last "for the life of the car." "Life" is a very nebulous concept. In the auto industry, an automobile is typically expected to have a life of 10 years / 150K miles. Hence, to the extent that a Prius traction battery lasts beyond that period of time, this should be viewed as a bonus enjoyed by the individual owner, rather than an entitlement that all Prius owners should expect.

If the 12V battery is relatively new, then once it is fully-charged it should be OK. If you keep the battery charged, it will typically last 6 years or more in geographic areas with moderate climates like yours. If you allow the battery to be drained repeatedly, its service life with be markedly shorter.

 

I'm in the school of thought to treat the 12 volt as an expendable. Just like an oil change: change the 12 volt battery at some interval, before it dies.

What interval is debatable. Some emergency vehicles replace 12 volt batteries bi-yearly, or even yearly. This is too extreme for the average car consumer, but food for thought. If the battery's 4 or 5 years old, and especially if it's been partially drained in past, might be time to change it.

 

Wow! . . . did I miss one of the threads in this post? No one mentioned the yellow-top optima from e-learn-aid?

Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 10

Tons of us here on PC went the optima route. The OEM Prius aux battery is weak to begin with ... somewhat undersized considering how many PC'rs abuse it ... running headlights ... sterio ... ventilation ... all with the "ready" mode not running. The OEM was really meant to just boot up the Prius' "ready" system, as Patrick mentioned. Ready mode recharges the aux battery ... accessory mode kills the aux battery pretty quickly. The aux 12v battery was never designed to "start" the car - in the traditional sense - in that that Prius has no cranking/starter motor. The electric drive motor starts the gas engine - only after the 12v aux battery boots up the Prius. The optima (being the same dimensions as the OEM aux battery) actually IS designed to crank over a starter motor - thus - you'll get better use without having to worry about dome lights mortally wounding your aux battery. and welcome to PC!

:welcome:

one other thing I didn't see mentioned. Once the OEM aux battery gets deep discharged (accidently) - it'll never be the same. Yes, you can recharge it. But a deep discharge on such a little battery causes the OEM to never be as robust as it was when new. Heck, your OEM is already a half decade old ... that means it's pretty much time. Most here (using prudence) replace the OEM around 5 years any way. There are tons of other posts here on PC that corroborate this.

 

As hill says, the Optima battery referenced in his post is a favorite of many on this forum. I had one installed a few months ago as a preventative measure -- my original battery was four years old and had just begun to show symptoms of being on the downhill side of life. I thought it better to be safe than sorry.

How do you test your battery to see what sort of shape it's in? Follow this link and the directions within. You don't even have to get out of the car:

http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html

Run the test. If the battery voltage doesn't fall within the listed parameters, you should buy a new battery and have it installed ASAP. Better safe than sorry. Hope this helps.

 

There are three dome lights and switches in the car. Make certain the right and left dome lights are off with their respective switches, and that the middle switch is not in the rightward position. Was hard to see in our car.